Abstract:
A multi-chip module and a chip set that comprises a plurality of the multi-chip modules. The multi-chip module includes a plurality of functional circuits provided on a substrate, the circuits defining a plurality of signal inputs and outputs. A plurality of pins are secured in a single row along the periphery of the substrate and are connected to the inputs and outputs. The pins include a set of 91 signal pins, two ground pins, and a power pin, the signal pins having a configuration complying in number and signal type with the IEEE-Prequirements to define an ISA bus. The multi-chip module includes a rectangular housing wherein the pins, in the form of gull wing pins, extend laterally from a peripherally extending wall. The ISA bus pins extend along one side and partially along adjacent sides of the rectangular module. The functional circuits of one embodiment of the module include a CPU, serial interfaces, a parallel interface, a hard drive interface, a floppy disk interface, a keyboard interface, and flash memory. Other multi-chip modules can include a PCMCIA interface, an Ethernet interface, or a display controller.

Description:
FIELD OF THE INVENTION 
     This invention relates to a multi-chip module. 
     BACKGROUND OF THE INVENTION 
     The most successful applications of computer technology have been those that people do not see. Microcontrollers and microprocessors govern automotive anti lock braking systems, automatic teller machines, elevators, subway ticket systems, and medical equipment. These hidden computers, otherwise known as embedded systems, permeate our lives. The embedded control market is, in fact, growing significantly faster than the desk top computing market. A major trend is the move from 4- and 8-bit processors to more powerful devices that provide more computing power and enable more &#34;friendly&#34; man-machine interfaces. A study by Desk Top Strategies showed that in 1994 over 320 million 16- and 32-bit embedded control processors were shipped to original equipment manufacturers (OEMs) for use in embedded control applications. In contrast, only 50 million were shipped to desk top computer manufacturers. The compound annual growth rate for 32-bit processors in the embedded market from 1992 to 1997 is projected to be 53 percent, compared with an estimated 32 percent in the desk top market. 
     The area of greatest growth in the embedded control market is the segment of ultra-miniature controllers for portable and transportable instruments. OEMs have indicated a strong interest in developing products with the PC architecture, but have found that size, integration, power, reliability, or cost constraints make existing broad-level products unsuitable for their applications. 
     The Cardio 386 developed by S-Mos Systems comprises a full function, small footprint, X86 computer that includes a CPU, all standard PC-type I/O controllers, PGA graphics, floppy and hard disk drive interfaces, DRAM, flash memory, and transparent power management. It adopts a PC AT architecture which complies with the ISA (industry standard architecture) bus pin configuration. However, it makes use of a unique edge connector comprising a plurality of tracks formed into rows on a card. This is received in a complementary slot for connection to peripheral devices. The use of a connector for connecting the module to a board makes its implementation inherently unreliable since vibrations can compromise the electrical connections between the various tracks forming the pins, and the corresponding contacts of the slot connector. Furthermore, no provision is made for integrating the module with proprietary hardware of OEMs (original equipment manufacturers). 
     Another prior art device is the Northstar III by Micro Module Systems that comprises a multi-chip module, including a Pentium processor, a cache controller, and RAM incorporated in a 349 pin PGA package. Once again, no facility is provided for interfacing with OEM proprietary hardware, Furthermore, the North Star module is packaged in a 349 pin PGA which makes simple direct connection to peripheral devices impossible without complicated track layout design. Therefore it does not allow the module to be simply dropped into an OEM system. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     It is an object of the invention to incorporate a multi-chip module in an ultra-miniature form factor. In particular it is an object of the invention to provide a module the size of a large integrated circuit. 
     It is a further object of the invention to provide an Intel X86 compatible computer module and peripheral controller modules wherein the computer module includes a CPU, I/O (a parallel port and two serial ports), a keyboard interface, a DRAM interface, floppy disk controller, hard disk controller, and flash disk functions based on Intel X86 architecture. Specifically, it is an object of the invention to provide a multi-chip module that provides an OEM (Original Equipment Manufacturer) with the facility for incorporating a feature set that is compatible with IBM PC/AT hardware, software, and bus pin configuration. 
     It is a further object of the invention to provide a module having low power consumption, broad thermal adaptability, low cost, and high reliability by eliminating cables and mounting hardware. 
     It is yet a further object of the invention to provide a module family having identical ISA bus pin configurations to facilitate easy interconnection. 
     It is yet a further object of the invention to provide a development board to form a platform for receiving a multi-chip module of the invention, thereby to provide for the quick development of pilot projects. 
     According to the invention there is provided a multi-chip module comprising a plurality of functional circuits provided on a substrate, the circuits defining a plurality of signal inputs and outputs, and a plurality of module pins secured in a single row along the periphery of the substrate and connected to the inputs and outputs, the module pins including a set of 91 pins, two ground pins, and a power pin, defining an ISA bus means, the signal pins having a configuration complying in number and signal type with the signal pins laid down under the IEEE-P996 specification, and as applied in the ISA (Industry Standard Architecture) requirements. For this reason it will hereinafter be referred as to as the ISA bus. 
     The module can be rectangular in shape, having a first side, a second side opposite the first side, a third side, and a fourth side, and is defined by an upper surface, a lower surface, and a peripheral wall, and wherein the plurality of pins extend from the peripheral wall. 
     The pins of the ISA bus means of the present invention preferably comprise: pin 38 corresponding to signal SA0; pin 39 corresponding to signal OSC; pin 40 corresponding to signal SA1; pin 41 corresponding signal SA2; pin 42 corresponding to signal BALE; pin 43 corresponding to signal SA3; pin 44 corresponding to signal SD15; pin 45 corresponding to signal TC; pin 46 corresponding to signal SA4; pin 47 corresponding to signal MASTER-; pin 48 corresponding to signal SD14; pin 49 corresponding to signal DACK2-; pin 50 corresponding to signal SA5; pin 51 corresponding to signal SD13; pin 52 corresponding to signal IRQ3; pin 53 corresponding to signal SA6; pin 54 corresponding to signal DRQ7; pin 55 corresponding to signal SD12; pin 56 corresponding to signal IRQ4; pin 57 corresponding to signal SA7; pin 58 corresponding to signal DACK7-; pin 59 corresponding to signal SD11; pin 60 corresponding to signal IRQ5; pin 61 corresponding to signal SA8; pin 62 corresponding to signal DRQ6; pin 63 corresponding to signal SD10; pin 64 corresponding to signal IRQ6OUT; pin 65 corresponding to signal IRQ6; pin 66 corresponding to signal SA9; pin 67 corresponding to GND; pin 68 corresponding to signal DACK6-; pin 69 corresponding to signal SD9; pin 70 corresponding to signal IRQ7OUT; pin 71 corresponding to signal IRQ7; pin 72 corresponding to signal SA10; pin 73 corresponding to signal DRQ5; pin 74 corresponding to signal SD8; pin 75 corresponding to signal SYSCLK; pin 76 corresponding to signal SA11; pin 77 corresponding to signal DACK5-; pin 78 corresponding to signal MEMW-; pin 79 corresponding to signal REFRESH-; pin 80 corresponding to signal SA12; pin 81 corresponding to signal DRQ0; pin 82 corresponding to signal MEMR-; pin 83 corresponding to signal DRQ1; pin 84 corresponding to signal SA13; pin 85 corresponding to VCC; pin 86 corresponding to signal DACK0-; pin 87 corresponding to signal LA17; pin 88 corresponding to signal DACK1-; pin 89 corresponding to signal SA14; pin 90 corresponding to signal IRQ14; pin 91 corresponding to signal LA18; pin 92 corresponding to signal DRQ3; pin 93 corresponding to signal SA15; pin 94 corresponding to signal IRQ15; pin 95 corresponding to signal LA19; pin 96 corresponding to signal DACK3-; pin 97 corresponding to signal SA16; pin 98 corresponding to signal IRQ12; pin 99 corresponding to signal LA20; pin 100 corresponding to signal IOR-; pin 101 corresponding to signal SA17; pin 102 corresponding to GND; pin 103 corresponding to signal IRQ11; pin 104 corresponding to signal LA21; pin 105 corresponding to signal IOW-; pin 106 corresponding to signal SA18; pin 107 corresponding to signal IRQ10; pin 108 corresponding to signal LA22; pin 109 corresponding to signal SMEMR-; pin 110 corresponding to signal SA19; pin 111 corresponding to signal IOCS16-; pin 112 corresponding to signal LA23; pin 113 corresponding to signal SMEMW-; pin 114 corresponding to signal AEN; pin 115 corresponding to signal MEMCS16-; pin 116 corresponding to signal SBHE-; pin 117 corresponding to signal IOCHRDY; pin 118 corresponding to signal SD00; pin 119 corresponding to signal (0WS-); pin 120 corresponding to signal SD1; pin 121 corresponding to signal SD2; pin 122 corresponding to signal DRQ2OUT; pin 123 corresponding to signal DRQ2; pin 124 corresponding to signal SD3; pin 125 corresponding to signal SD4; pin 126 corresponding to signal IRQ9; pin 127 corresponding to signal SD5; pin 128 corresponding to signal SD6; pin 129 corresponding to signal RESETDRV; pin 130 corresponding to signal SD7; and pin 131 corresponding to signal IOCHCK-. The ISA bus pins preferably extend along the first side and at least partially along the third and fourth sides. The multi-chip module can include 240 module pins. 
     The functional circuits in a module can include a central processing unit. The functional circuits can further include two serial interfaces, a parallel interface, a hard drive interface, a floppy disk interface, a keyboard interface, and flash memory. 
     Other modules can include functional circuits that include a PCMCIA interface, an Ethernet interface, or a display controller. 
     The substrate can comprise a printed circuit board and the functional circuits comprise semiconductor devices which can be packaged or can be in bare die form secured to the printed circuit board. 
     Further, according to the invention, there is provided a multi-chip module comprising a plurality of functional circuits encapsulated in a rectangular housing, the housing having an upper surface and a lower surface, and a peripheral wall extending along a first side, a second side opposite the first side, a third side, and a fourth side; and a plurality of pins extending laterally from the peripheral wall, wherein the pins include a set of 91 signal pins, two ground pins and a power pin defining an ISA bus means, the signal pins of which comply in number and signal type, with the signal pins laid down under the IEEE-P996, and as applied in the ISA (Industry Standard Architecture) requirements. 
     Still further, according to the invention, there is provided a module family comprising a plurality of functionally different modules, wherein each module has a plurality of pins and the pins of each module include a set of 91 signal pins, two ground pins, and a power pin, defining an ISA bus means, the signal pins of which comply in number and signal type with the signal pins laid down under the IEEE-P996, and as applied in the ISA (Industry Standard Architecture) requirements. 
     Each module can comprise at least one functional circuit encapsulated in a rectangular housing, the housing having an upper surface and a lower surface, and a peripheral wall extending along a first side, a second side opposite the first side, a third side, and a fourth side, and wherein the pins of the module extend laterally from the peripheral wall. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of a multi-chip module of the invention; 
     FIG. 2 is a side view of the module of FIG. 1; 
     FIG. 3 is a block diagram of a multi-chip module of the invention; 
     FIG. 4 is a schematic representation of a multi-chip module of the invention indicating the configuration of the pins; 
     FIG. 5 shows a PC board layout for a development board showing the mounting site for the module of FIG. 1, and 
     FIG. 6 is a schematic representation of a number of different modules in accordance with the invention connected to each other by means of their ISA buses to form a module family of the invention. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     A need exists in the field of embedded applications for small, highly reliable computer systems that draw little power, are easy to integrate, have broad thermal adaptability and are relatively inexpensive. Applications for such devices include medical instruments, data logging devices, security systems, test equipment, point-of-sale terminals, communications devices, such as Internet and facsimile machines, and navigational instruments. OEMs (original equipment manufacturers) typically use the Intel X86 architecture since it offers the world&#39;s largest body of hardware and software. The present invention has accordingly been developed to address the problems in the prior art by providing a multi-chip module packaged to resemble a large integrated circuit chip comprising a 240 pin QFP having an overall footprint of 59.54×79.88 min. The module includes a set of pins constituting a bus for connection to the OEM designer&#39;s proprietary internal hardware. The invention specifically contemplates providing this bus with a configuration complying with the ISA (Industry Standard Architecture) requirements. This will allow the OEM designer quickly to incorporate IBM PC/AT hardware and software and to implement the module in ISA compatible proprietary product designs. The module is now described in greater detail with reference to FIGS. 1 and 2 which show a plan view and a side view, respectively, of the module. 
     The module 10 is a 240 pin QFP with gull wing pins having a 0.762 mm. pitch. The body is rectangular, the one side of which measures 76.2 mm and the overall footprint in this embodiment being 59.54×79.88 mm. The pins themselves are typically 0.5 mm wide, and the dimensions of distances 12 and 14 in FIG. 1 are 3.5 mm for this embodiment. By using a chip-like package in which the pins are formed around the periphery of the module 10 in a single row as illustrated in FIGS. 1 and 2, the module 10 can easily be soldered into place to form a very sturdy, reliable set of connections. Furthermore, tracks can be designed to lead directly from the pins to another device by making use of PC board tracks on one or both surfaces of the PC board without the need for several layers to route the various tracks. Since the pins are soldered directly to the interconnecting tracks, the system has inherent reliability in that it eliminates cables and mounting hardware that could otherwise vibrate loose. As many as half a dozen interconnecting cables, assorted connectors and mounting hardware required with many existing prior art single board computers, are thereby eliminated. 
     The module thus provides an Intel X86 compatible computer in an ultra-miniature form factor that can be integrated as easily as a semiconductor device and provides the full functionality of a desk top computer. As is described in greater detail below, the same concepts of using a chip-like module using a QFP package with gull wing pins and having an ISA compatible bus is extended also to peripheral controller modules. 
     By integrating a full X86 AT-compatible computer onto a proprietary OEM design, the need for multiple boards is eliminated, thereby eliminating cables and mounting hardware. 
     The full compatibility with PC-AT ISA allows for easy integration with low-cost hardware peripherals. The ISA, compliant bus makes it easy to interface with proprietary hardware design. 
     One embodiment of the module 10, having a CPU as one of its functional circuits, is illustrated in FIG. 3 and includes the standard I/O interfaces, serial ports, a parallel port, and floppy and hard disk interfaces allowing standard hardware, cables, and software libraries to be incorporated in the design. The module 10 includes an 80386 SX CPU 20 which is connected to a DRAM bus and an ISA bus 24 by means of core logic 26. The core logic controls AT-compatible DMA controllers, interrupt controllers, and timers/counters. It also controls the AT keyboard controller 28 and the real time clock 30. Two serial ports 32, 34 and a parallel port 36 are provided, as are a floppy disk controller 40 and an IDE hard drive interface 42. In order to facilitate total solid state operation, internal flash memory 44 is provided that is controlled by a solid state flash disk controller 46. Power is controlled by means of a power monitor 48 that provides a power saving function by controlling CPU sleep modes, and by a watch dog timer 50. The watch dog timer 50 monitors CPU cycles to detect interrupts in the cycle thereby allowing the system to be automatically reset after a predetermined time delay. 
     The microprocessor and various controllers and interfaces comprise chips, preferably in die form, mounted on a multi-layer PC board, e.g. ten-layers. The CPU 20 is a standard 33 MHz 80386 SX CPU having a DRAM controller for supporting up to 16M bytes of DRAM. 
     The standard DRAM interface provides all the signals for connecting standard page-mode DRAMs of various configurations, including standard 8- and 9-bit 30-pin SIMM modules and discrete components, such as standard 1M×4 and 4M×4 DRAM chips. The interface is designed to support 70 ns or faster DRAMs. The DRAM interface consists of: 
     
         ______________________________________• Multiplexed addresses                 MA00-MA10• Bidirectional data                 D0-D15• Column Address Strobes                 CASL0- to CASL3- (low byte)                 CASH0- to CASH3- (high byte)• Row Address Strobes                 RAS0- to RAS3-• Memory Write Strobe                 DRWE-______________________________________ 
    
     The serial ports 32, 34 are PC-compatible asynchronous serial ports, typically treated as COM 1 and COM 2 devices by DOS. 
     
         ______________________________________Serial   Typical     I/O      StandardPort     Usage       Address  Interrupt______________________________________Serial 1 COM1        3F8-3FF  IRQ4Serial 2 COM2        2F8-2FF  IRQ3          Serial Port Rersources______________________________________ 
    
     Either or both serial ports can be disabled using SETUP. When disabled, the port&#39;s I/O address and interrupt are made available for other expansion devices on the PC bus. 
     A full complement of input and output handshaking lines are supported by the serial ports, and all serial port signals are at standard LSTTL levels. In another embodiment, RS232C signal compatibility can be achieved by including a TTL-RS232C level converter to provide the necessary bipolar signal levels. The parallel port is a fully-compatible PC/AT parallel port providing bidirectional operation. It is typically used to support a line printer. As appears from the table below: 
     
         ______________________________________Parallel  Typical     I/O      StandardPort      Usage       Address  Interrupt______________________________________Parallel 1     LPT1        378      IRQ7   Parallel Port Resources______________________________________ 
    
     4.7K-ohm pull-ups (+5 V) are typically provided to the following parallel port signals: 
     STROBE- 
     SLIN- 
     INIT- 
     AUTOFD- 
     Generally, if the parallel port will be connected to a cable for high speed data communication (as opposed to static digital output levels or static TTL level sensing), certain signals require a 2.2 nF capacitor connected to ground. 
     These include: 
     PD0-PD7 
     STRB- 
     Parallel port registers are provided for the parallel port as appears from the table set out below: 
     
         ______________________________________          Signal            Active  DB25FRegister Bit   Name        In/Out                            High/Low                                    Pin______________________________________DATA     0     PD0         I/O   HIGH    2(A+0)    1     PD1         I/O   HIGH    3    2     PD2         I/O   HIGH    4    3     PD3         I/O   HIGH    5    4     PD4         I/O   HIGH    6    5     PD5         I/O   HIGH    7    6     PD6         I/O   HIGH    8    7     PD7         I/O   HIGH    9STATUS   0     1           --    --      --(A+1))   1     1           --    --      --    2     1           --    --      --    3     ERROR-      IN    LOW     15    4     SLCT-       IN    HIGH    13    5     PE          IN    HIGH    12    6     ACK-        IN    HIGH    10    7     BUSY        IN    LOW     11CONTROL  0     STRB-       OUT   LOW     1    1     AUTOFD-     OUT   LOW     14(A+2)    2     INIT-       OUT   HIGH    16    3     SLCTIN-     OUT   LOW     17    4     IRQ ENABLE  --    HIGH    --    5     1           --    --      --    6     1           --    --      --    7     1           --    --      --    Parallel Port Registers______________________________________ 
    
     The DOS-compatible floppy drive interface 40 allows cable connections for up to four floppy drives. In PC-compatible systems, the BIOS and DOS support two drives. These are configured using the BIOS SETUP function. Hardware controls for two additional drives are provided. 
     The floppy drive interface supports the following standard floppy formats: 
     
         ______________________________________Capacity  Drive Size   Tracks  Data Rate______________________________________360K      51/4 inch    40      250 KHz1.2M      51/4 inch    80      500 KHz720K      31/2 inch    80      250 KHz1.44M     31/2 inch    80      500 KHz______________________________________ 
    
     The various floppy interface resources are given in the table below 
     
         ______________________________________Resource     Function______________________________________I/O Address  3F2 FDC Digital Output Register (LDOR)3F0h-3F7h    3F4 FDC Main Status Register        3F5 FDC Data Register        3F7 FDC Control Register (LDCR)IRQ6         InterruptDRQ2-DACK2   DMA Controller ChannelFloppy Interface Resources______________________________________ 
    
     Outputs to the floppy drive and from the floppy drive are &#34;open collector&#34;. Pull-up resistors are therefore required for proper termination, both on the SMX/386 board and on one of the attached floppy drives (not both). 
     330-Ohm pull-ups are required for the following floppy interface signals: 
     DSKCHG- 
     RDATA- 
     WRPRT- 
     TRK0- 
     INDEX- 
     The pin numbers and functions associated with the floppy drive are given in the table below: 
     
         ______________________________________  FloppyPin    Pin      Signal Name                      Function  In/Out______________________________________11     2        DENSEL     Speed/Precomp  4        N/A                  N/A  6        N/S        Key pin   N/A12     8        INDEX-     Index Pulse                                IN13     10       MTR0-      Motor On 0                                OUT15     12       DRV1-      Drive Select 2                                OUT18     14       DRV0-      Drive Select 1                                OUT20     16       MTR1-      Motor On 1                                OUT22     18       DIR-       Direction Select                                OUT23     20       STEP-      Step Pulse                                OUT24     22       WDATA-     Write Data                                OUT25     24       WGATE-     Write Gate                                OUT26     26       TRK0-      Track 0   INPUT27     28       WRPRT-     Write Protect                                INPUT28     30       RDATA-     Read Data INPUT29     32       HDSEL-     Head Select                                OUT30     34       DSKCHG-    Disk Change                                INPUT  1-33     Ground     Ground     Floppy Drive Interface______________________________________ 
    
     The IDE hard drive interface 42 is a standard interface used in PC-compatible systems for hard disk drives. Up to two drives can be connected in a master-slave arrangement. The resources are depicted in the table below: 
     
         ______________________________________Resource           Function______________________________________I/O Address        Hard Disk Interface1F0h-1F7hIRQ14              InterruptIDE Hard Disk Resources______________________________________ 
    
     The IDE interface pins are arranged to easily attach to a male PC-mounted ribbon-cable connector, the IDE drives typically being attached to the drive interface using a 40-pin ribbon cable. 
     The pin configuration for the IDE interface is given in the table below: 
     
         ______________________________________ IDEPin   Pin    Signal Name                   Function     In/Out______________________________________223   1      HDRESET-   Reset signal from host                                OUT 2      GND        Ground       OUT224   3      IDED07     Data bit 7   I/O225   4      HDD08      Data bit 8   I/O226   5      HDD06      Data bit 6   I/O227   6      HDD09      Data bit 9   I/O228   7      HDD05      Data bit 5   I/O229   8      HDD10      Data bit 10  I/O230   9      HDD04      Data bit 4   I/O231   10     HDD11      Data bit 11  I/O232   11     HDD03      Data bit 3   I/O233   12     HDD12      Data bit 12  I/O234   13     HDD02      Data bit 2   I/O235   14     HDD13      Data bit 13  I/O236   15     HDD01      Data bit 1   I/O237   18     HDD14      Data bit 14  I/O238   17     HDD00      Data bit 0   I/O239   18     HDD15      Data bit 15  I/O 19     GND        Ground       OUT 20     KEY        Keyed pin    N/C 21     N/A        Reserved     N/C 22     GND        Ground       OUT240   23     HDIOW-     Write strobe OUT 24     GND        Ground       OUT1     25     HDIOR-     Read strobe  OUT 26     GND        Ground       OUT 27     RSVD       Reserved     N/C2     28     HDALE      Address latch enable                                OUT 29     RSVD       Reserved     N/C 30     GND        Ground       OUT237   31     HDD14      Drive Interrupt request                                IN         IDE Drive Interface______________________________________ 
    
     The pin configuration for the module 10 as a whole is illustrated in FIG. 4 and is given in the pin description table below: 
     
         ______________________________________Pin  Pin Name  Description            Type______________________________________1    HDIOR-    IDE I/O Read, active low. Buffered version                                 024          of IOR2    HDALE     IDE Address Latch Enable, active high.                                 024          Buffered version of BALE3    IRQ14     IDE Interrupt Request 14. For use with                                 I          IDE interface. Same signal appears on pin          90.4    IOCS16    IDE I/O Chip Select 16. A low requests a                                 I          16-bit transfer on the SA bus. Same          signal appears on pin 238. This one is          used for the IDE interface.5    HDA1      IDE Address 1. Buffered version of SA1.                                 0246    HDA0      IDE Address 0. Buffered version of SA0                                 0247    HDA2      IDE Address 2. Buffered version of SA2                                 0248    HDCS-     IDE Chip Select. A low indicates that data                                 024          is being transferred to or from the IDE          drive.9    FDCS-     Floppy disk Chip Select. A low indicates                                 024          that data is being transferred to or from          the floppy disk.10   LEDIN     LED signal from IDE drive                                 I11   DENSEL12   IDEX      Floppy disk index pulse, input from drive                                 I13   MTR0-     Floppy disk active lower open drain output          selects motor driver 0. The motor enable          bits are software controlled via the          floppy&#39;s Digital Output Register (DOR).14   MTR2-     Floppy disk active low open drain output          selects motor driver 2. The motor enable          bits are software controlled via the          floppy&#39;s Digital Output Register (DOR).15   DRV1-     Floppy disk active lower open drain output          that selects floppy drive 116   DRV3-     Floppy disk active low open drain output          that selects floppy drive 317   GND18   DRV0-     Floppy disk active low open drain output          that selects floppy drive 019   DRV2-     Floppy disk active low open drain output          that selects floppy drive 220   MTR1-     Floppy disk active low open drain output          selects motor driver 1. The motor enable          bits are software controlled via the          floppy&#39;s Digital Output Register (DOR).21   MTR3-     Floppy disk active low open drain output          selects motor driver 3. The motor enable          bits are software controlled via the          floppy&#39;s Digital Output Register (DOR).22   DIR       Floppy disk open drain output that controls          floppy read/write head movement          direction. Low=set pin.23   STEP      Floppy disk active low output provides the          step pulse to move the floppy read/write          head24   WDATA-    Floppy disk active lower signal writes          precompensated serial data to the selected          floppy drive. This is a high open current          drain output and is gated internally with          WGATE-.25   WGATE-    Floppy disk active low open drain signal          that enables the head to write onto the          floppy disk.26   TRK0-     Floppy disk active lower Schmitt input                                 IS          indicates that the head is on track 0 of the          selected drive27   WRPRT-    Floppy disk active low Schmitt input                                 IS          indicating that the disk is write protected.          Any WDATA-command is ignored.28   RDATA-    Floppy disk active lower Schmitt input that                                 IS          reads raw data from the floppy disk.29   HDSEL     Floppy disk open drain output that selects          the head on the selected drive. Low=side          0.30   DSKCHG    Floppy disk input signal indicating that                                 Ihe          floppy door has been opened.31   5VBB32   GND33   PF1       Powerfail34   PF0       Powerfail35   MR-       Powerfail36   RTCIRQ-   Alarm output from the onboard real time          clock37   WD0       Watchdog timer38   SA00      ISA System Address 00  02439   OSC       ISA 14.318 MHz clock. This clock is          asynchronous to all other system clocks40   SA01      ISA System Address 01  02441   SA02      ISA System Address 02  02442   BALE      ISA Buffered Address Latch Enable43   SA03      ISA System Address 03  02444   SD15      ISA System Data 1545   TC        ISA DMX Terminal Court46   SA04      ISA System Address 04  02447   MASTER-   ISA48   SD14      ISA System Data 1449   DACK2-    ISA DMA 2 Acknowledge strobe50   SA05      ISA System Address 05  02451   SD13      ISA System Data 1352   IRQ3      ISA Interrupt Request 3                                 I53   SA06      ISA System Address 06  02454   DRQ7      ISA DMA 7 Request      I55   SD12      ISA System Data 1256   IRQ4      ISA Interrupt Request 4                                 I57   SA07      ISA System Address 07  02458   DACK7-    ISA DMA 7 Acknowledge strobe59   SD11      ISA System Data 1160   IRQ5      ISA Interrupt Request 5                                 I61   SA08      ISA System Address 08  02462   DRQ6      ISA DMA 6 Request      I63   SD10      ISA System Data 1064   IRQ6OUT   Floppy disk interrupt request. Normally          connects to IRQ6 (pin 65)65   IRQ6      ISA Interrupt Request 6                                 I66   SA09      ISA System Address 09  02467   GND68   DACK6-    ISA DMA 6 Acknowledge strobe69   SD09      ISA System Data 0970   IRQ7OUT   Parallel port interrupt request, Normally          connects to IRQ7 (pin 71).71   IRQ7      ISA Interrupt Request 7                                 I72   SA10      ISA System Address 10  02473   DRQ5      ISA DMA 5 Request      I74   SD08      ISA System Data 0875   SYSCLK    ISA System Clock76   SA11      ISA System Address 11  02477   DACK5-    ISA DMA 5 Acknowledge strobe78   MEMW-     ISA active low memory write strobe79   REFRESH-  ISA active low signal indicating current          bus cycle is a memory refresh80   SA12      ISA System Address 12  02481   DRQ0      ISA DMA 0 Request      I82   MEMR-     ISA active low memory read strobe83   DRQ1      ISA DMA 1 Request      I84   SA13      ISA System Address 13  02485   VCC86   DACK0-    ISA DSMA 0 Acknowledge strobe87   LA17      ISA Latched Address 17 02488   DACK1-    ISA DMA 1 Acknowledge strobe89   SA14      ISA System Address 14  02490   IRQ14     ISA Interrupt Request 14, normally used                                 I          for IDE interface91   LA18      ISA Latched address 18 02492   DRQ3      ISA DMA 3 Request strobe93   SA15      ISA System Address 15  02494   IRQ15     ISA Interrupt Request 15                                 I95   LA19      ISA Latched Address 19 02496   DACK3-    ISA DMA 3 Acknowledge strobe97   SA16      ISA System Address 16  02498   IRQ12     ISA Interrupt Request 12                                 I99   LA20      ISA Latched Address 20 024100  IOR-      ISA I/O Read strobe101  SA17      ISA System Address 17  024102  GND103  IRQ11     ISA Interrupt Request 11                                 I104  LA21      ISA Latched Address 21 024105  IOW-      ISA I/O Write strobe106  SA18      ISA System Address 18  024107  IRQ10     ISA Interrupt Request 10                                 I108  LA22      ISA Latched Address 22 024109  SMEMR-    ISA System Memory Read strobe110  SA19      ISA System Address 19  024111  IOCS16-   ISA 16-bit I/O Chip Select request.                                 I          Indicates that the current I/O transaction is          16-bits.112  LA23      ISA Latched Address 23 024113  SMEMW-    ISA System Memory Write strobe114  AEN       ISA Address Enable115  MEMCS16   ISA 16-bit Memory Chip Select request.                                 I          Indicates that the current memory          transaction is 16-bits.116  SBHE-     ISA System Byte High Enable117  IOCHRDY   ISA I/O Channel Ready. A low adds wait                                 I          states to the current ISA bus cycle118  SD00      ISA System Data 00119  OWS-      ISA active low causing cuurent memory                                 I          cycle to be controlled without additional          wait states.120  SD01      ISA System Data 01121  SD02      ISA System Data 02122  DRQ2OUT   Floppy DMA 2 Request. Normally          connected to DRDQ2 (pin 123)123  DRQ2      ISA DMA 2 Request strobe124  SD03      ISA System Data 03125  SD04      ISA System Data 04126  IRQ9      ISA Interrupt Request 09127  SD05      ISA System Data 05128  SD06      ISA System Data 06129  RESETDRV  ISA active high system reset signal130  IOCHCHK   ISA gated non-maskable interrupt input131  IOCHCHK-  ISA gated non-maskable interrupt input                                 I132  HISPEED   Input to select CPU speed, High=high                                 I          speed.133  SPKR      Speaker output134  KDATA     Keyboard135  KCLOCK    Keyboard clock136  PWRDN-137  GND138  COLOR     Video Color/Mono jumper                                 I139  KBLOCK    Keyboard lock. Low blocks keyboard                                 I          input140  SLCT      Parallel Port141  PE        Parallel Port142  BUSY      Parallel Port143  ACK-      Parallel Port144  PD7       Parallel Port Data 7145  PD6       Parallel Port Data 6146  PD5       Parallel Port Data 5147  PD4       Parallel Port Data 4148  PD3       Parallel Port Data 3149  SLCTIN-   Parallel Port150  PD2       Parallel Port Data 2151  INIT-     Parallel Port152  PD1       Parallel Port Data 1153  ERR-      Parallel Port154  GND155  PD0       Parallel Port Data 0156  AUTOFD    Parallel Port157  STRB-     Parallel Port158  DCD2      Serial Port 2 Data Carrier Detect159  DSR2      Serial Port 2 Data Set Ready160  RXD2      Serial Port 2 Receive Data161  RTS2      Serial Port 2 Request To Send162  TXD2      Serial Port 2 Transmit Data163  CTS2      Serial Port 2 Clear To Send164  DTR2      Serial Port 2 Data Terminal Ready165  R12       Serial Port 2 Ring Indicator166  DCD1      Serial Port 1 Data Carrier Detect167  DSR1      Serial Port 1 Data Set Ready168  RXD1      Serial Port 1 Receive Data169  RTS1      Serial Port 1 Request to Send170  TXD1      Serial Port 1 Transmit Data171  CTS1      Serial Port 1 Clear to Send172  DTR1      Serial Port 1 Data Terminal Ready173  RI1       Serial Port 1 Ring Indicator174  GAMECS175  RAS3-     DRAM Row Address Strobe 3176  RAS2-     DRAM Row Address Strobe 2177  RAS1-     DRAM Row Address Strobe 1178  RAS0-     DRAM Row Address Strobe 0179  DP1       DRAM parity bit for high byte memory180  DP0       DRAM parity bit for low byte memory181  D15       DRAM Data Bit 15182  D07       DRAM Data Bit 7183  D14       DRAM Data Bit 14184  D06       DRAm Data Bit 6185  DRWE-     DRAM memory write strobe186  D13       DRAM Data Bit 13187  GND188  D05       DRAM Data Bit 5189  MA10      DRAM multiplexed memory address 10190  MA09      DRAM multiplexed memory address 9191  MA08      DRAM multiplexed memory address 8192  D12       DRAM Bata Bit 12193  D04       DRAM Data Bit 4194  MA07      DRAM multiplexed memory address 7195  MA06      DRAM multiplexed memory address 6196  D11       DRAM Data Bit 11197  D03       DRAM Data Bit 3198  MA05      DRAM multiplexed memory address 5199  MA04      DRAM multiplexed memory address 4200  D10       DRAM Data Bit 10201  D02       DRAM Data Bit 2202  MA03      DRAM multiplexed memory address 3203  MA02      DRAM multiplexed memory address 2204  D09       DRAM Data Bit 9205  VCC206  D01       DRAM Data Bit 1207  MA01      DRAM multiplexed memory address 1208  MA00      DRAM multiplexed memory address 0209  D08       DRAM Data Bit 8210  D00       DRAM Data Bit 0211  CASH3-    DRAM Column Address Strobe, High byte 3212  CASL3-    DRAM Column Address Strobe, Low byte 3213  CASH2-    DRAM Column Address Strobe, High byte 2214  CASL2-    DRAM Column Address Strobe, Low byte 2215  CASH1-    DRAM Column Address Strobe, High byte 1216  CASL1-    DRAM Column Address Strobe, Low byte 1217  CASH0-    DRAM Column Address Strobe, High byte 0218  CASL0-    DRAM Column Address Strobe, Low byte 0219  BDIS220  XROMCS-221  LEDOUT-222  GND223  HDRESET-  IDE224  IDE07     IDE Data Bit 7225  HDD08     IDE Data Bit 8226  HDD06     IDE Data Bit 6227  HDD09     IDE Data Bit 9228  HDD05     IDE Data Bit 5229  HDD10     IDE Data Bit 10230  HDD04     IDE Data Bit 4231  HDD11     IDE Data Bit 11232  HDD03     IDE Data Bit 3233  HDD12     IDE Data Bit 12234  HDD02     IDE Data Bit 2235  HDD13     IDE Data Bit 13236  HDD01     IDE Data Bit 1237  HDD14     IDE Data Bit 14238  HDD00     IDE Data Bit 0239  HDD15     IDE Data Bit 15240  HDIOW-    IDE buffered I/O Write strobe______________________________________ 
    
     As mentioned above, the core logic 26 supports a DRAM bus 22 and an ISA compatible expansion bus 24 complying in number and signal type with the IEEE-P996 requirements (and corresponding to the ISA (Industry Standard Architecture) requirements). The pin configuration for the expansion bus 24 is given in the table below with corresponding pin numbers for expansion bus connectors A, B, C, D. The bus 24 comprises 94 pins that includes VCC and two GND pins. 
     
         __________________________________________________________________________ SignalPin   Name   Function  In/Out                      Current                           Load*__________________________________________________________________________38 A31 SA0    Address bit 0                  I/O 12 mA                           PU39 B30 OSC    14.318 MHz clock                  Out 6 mA 33 SER40 A30 SA1    Address bit 1                  I/O 12 mA                           PU41 A29 SA2    Address bit 2                  I/O 12 mA                           PU42 B28 BALE   Address latch                  Out 12 mA        enable43 A28 SA3    Address bit 3                  I/O 12 mA                           PU44 C18 SD15   System Data bit                  I/O 12 mA                           PU        1545 B27 TC     DMA Terminal                  Out 4 mA        Count46 A27 SA4    Address bit 4                  I/O 12 mA                           PU47 D17 MASTER-        Bus master assert                  In  N/A  330 PU48 C17 SD14   System Data bit                  I/O 24 mA                           PU        1449 B26 DACK2- DMA       Out 4 mA        Acknowledge 250 A26 SA5    Address bit 5                  I/O 12 mA                           PU51 C16 SD13   System Data bit                  I/O 24 mA                           PU        1352 B25 IRQ3   Interrupt Request 3                  In  N/A  PU53 A25 SA6    Address bit 6                  I/O 12 mA                           PU54 D15 DRQ7   DMA Request 7                  In  N/A  PD55 C15 SD12   System Data bit                  I/O 24 mA                           PU        1256 B24 IRQ4   Interrupot Request 4                  In  N/A  PU57 A24 SA7    Address bit 7                  I/O 12 mA                           PU58 D14 DACK7- DMA       Out 4 mA        Acknowledge 759 C14 SD11   System Data bit                  I/O 24 mA                           PU        1160 B23 IRQ5   Interrupt Request 5                  In  N/A  PU61 A23 SA8    Address bit 8                  I/O 12 mA                           PU62 D13 DRQ6   DMA Request 6                  In  N/A  PD63 C13 SD10   System Data bit                  I/O 24 mA                           PU        1064    IRQ6OUT        Floppy Disk        Interrupt Request65 B22 IRQ6   Interrupt Request 6                  In  N/A  PU66 A22 SA9    Address bit 9                  I/O 12 mA                           PU67    GND68 D12 DACK6- DMA       Out 4 mA        Acknowledge 669 C12 SD9    System Data bit 9                  I/O 24 mA                           PU70    IRQ7OUT        Parallel Port        Interrupt Request71 821 IRQ7   Interrupt Request 7                  In  N/A  PU72 A21 SA10   Address bit 10                  I/O 12 mA                           PU73 D11 DRQ5   DMA Request 5                  In  N/A  PD74 C11 SD8    System Data bit 8                  I/O 24 mA                           PU75 B20 SYSCLK System clock (8                  Out 12 mA        MHz)76 A20 SA11   Address bit 11                  I/O 12 mA                           PU77 D10 DACK5- DMA       Out 4 mA        Acknowledge 578 C10 MEMW-  Memory Write                  I/O 6 mA PU, 33                           SER79 B19 REFRESH-        Memory Refresh                  I/O 6 mA 470 PU,                           33 SER80 A19 SA12   Address bit 12                  I/O 12 mA                           PU81 D9 DRQ0   DMA Request 9                  In  N/A  PD82 C9 MEMR-  Memory Read                  I/O 6 mA PU, 33                           SER83 B18 DRQ1   DMA Request 1                  In  N/A  PD84 A18 SAT3   Address bit 13                  I/O 12 mA                           PU85    VCC86 D8 DACK0- DMA       Out 4 mA        Acknowledge 087 C8 LA17   Address bit 17                  I/O 24 mA88 B17 DACK1- DMA       Out 4 mA        Acknowledge 189 A17 SA14   Address bit 14                  I/O 12 mA                           PU90 D7 IRQ14  Interrupt Request                  In  N/A  PU        1491 C7 LA18   Address bit 18                  I/O 24 mA92 B16 DRQ3   DMA Request 3                  In  N/A  PD93 A16 SA15   Address bit 15                  I/O 12 mA                           PU94 D6 IRQ15  Interrupt Request                  In  N/A  PU        1595 C6 LA19   Address bit 19                  I/O 24 mA96 B15 DACK3- DMA       Out 4 mA        Acknowledge 397 A15 SA16   Address bit 16                  I/O 12 mA                           PU98 D5 IRQ12  Interrupt Request                  In  N/A  PU        1299 C5 LA20   Address bit 20                  I/O 24 mA100   B14 IRQ-   I/O Read  I/O 6 mA PU101   A14 SA17   Address bit 17                  I/O 12 mA                           PU102   GND103   D4 IRQ11  Interrupt Request                  In  N/A  PU        11104   C4 LA21   Address bit 21                  I/O 24 mA105   B13 IOW-   I/O Write I/O 6 mA PU106   A13 SA18   Address bit 18                  I/O 12 mA                           PU107   D3 IRQ10  Interrupt Request                  In  N/A  PU        10108   C3 LA22   Address bit 22                  I/O 24 mA109   B12 SMEMR- Mem Read (lower                  I/O 6 mA 33 SER        1MB)110   A12 SA19   Address bit 19                  I/O 12 mA                           PU111   D2 IOCS16-        16-bit I/O access                  In  N/A  330 PU112   C2 LA23   Address bit 23                  I/O 24 mA113   B11 SMEMW- Mem Write (lower                  I/O 6 mA 33 SER        1 MB)114   A11 AEN    Address Enable                  I/O 12 mA                           PU115   D1 MEMCS16-        16-bit mem access                  In  N/A  330 PU116   C1 SBHE-  Bus High Enable                  I/O 12 mA                           PU117   A10 IOCHRDY        Processor Ready                  In  N/A  1K PU        Ctrl118   A9 SD00   System Data bit 0                  I/O 24 mA                           PU119   B8 ENDXFR-        Zero wait state                  In  N/A  330 PU (OWS-)120   A8 SD1    System Data bit 1                  I/O 24 mA                           PU121   A7 SD2    System Data bit 2                  I/O 24 mA                           PU122   DRQ2OUT        Floppy DMA 2        Request123   B6 DRQ2   DMA Request 2                  In  N/A  PD124   A6 SD3    System Data bit 3                  I/O 24 mA                           PU125   A5 SD4    System Data bit 4                  I/O 24 mA                           PU126   B4 IRQ9   Interrupt request 9                  In  N/A  PU127   A4 SD5    System Data bit 5                  I/O 24 mA                           PU128   A4 SD6    System Data bit 6                  I/O 24 mA                           PU129   B2 RESETDRV        System reset                  Out 24 mA        signal130   A2 SD7    System Data bit 7                  I/O 24 mA                           PU131   A1 IOCHCK-        Sub NMI input                  In  N/A  4.7K PU__________________________________________________________________________ 
    
     The exact pin configuration as illustrated for the expansion bus on Page 5 is a critical feature of the invention. Since it forms a single row of pins on the module 10, the pins can be easily connected directly to the expansion bus connectors without having to resort to multiple layer boards to route the PC board tracks from the module 10 to the expansion bus connectors A, B, C, D. Furthermore, as mentioned above, the present invention includes both microprocessor modules as illustrated in FIG. 3, as well as peripheral controller modules such as display controller modules, Ethernet control modules, and PCMCIA compatible modules for extended memory (RAM, ROM, EEPROM, flash memory, etc.), as well as for modem, fax, and network interfaces, and also for wireless communication devices. By providing an identical pin configuration for the ISA buses, the various modules can easily be connected to one another. 
     A further feature of the invention is illustrated in FIG. 5. FIG. 5 illustrates a card 54 having a mounting site 56 for a module having a pin configuration as described above with reference to FIG. 4. The card 54 provides an integrated way for system development in standard ISA passive backplane systems. The card includes an AT-bus and a PC/104 bus, and occupies a single slot in an AT-class (16-bit) passive backplane. This allows development to be performed using a terminal on a serial port as a console. A standard VGA or SVGA display controller can be plugged into another slot on the backplane if desired. Instead, a PC/104 display controller can be installed directly on the PC/104 header 58 on the card 54. Since the module 10 is fully compatible with PC/AT ISA, a wide selection of hardware peripherals may be integrated. The ISA-compatible bus allows an OEM to easily interface his proprietary hardware design with the module 10. Furthermore, the standard BIOS and embedded DOS allows application software to be developed using standard desk top PCs and standard development tools for implementation on the system using one or more modules of the present invention. It will be appreciated that, depending on the nature of the module, the size of the module and the number of pins may vary, however it is an important feature of this invention that the pins for the ISA bus retain their configuration in each module to allow the modules to be readily connected to one another as illustrated in FIG. 6 in which different modules 60, 62, 64 of the invention are connected to each other by means of bus lines 66, 68 extending between the ISA compatible bus pins indicated by reference numerals 70, 72, 74, respectively.