Abstract:
A system and method for testing a wireless data packet signal transceiver device under test (DUT) by using DUT control circuitry separate from a tester to access and execute test program instructions for controlling the DUT during testing with the tester. The test program instructions can be provided previously and stored for subsequent access and execution under control of the tester or an external control source, such a personal computer. Alternatively, the test program instructions can be provided by the tester or external control source immediately prior to testing, such as when beginning testing of a DUT with new or different performance characteristics or requirements. Accordingly, specialized testing of different DUTs while accounting for differences among various chipsets employed by the DUTs can be performed in coordination with a standard tester configuration without need for reconfiguring or reprogramming of the tester.

Description:
BACKGROUND 
     The present invention relates to testing data packet transceiver devices under test (DUTs), and in particular, to performing specialized testing of different DUTs while accounting for differences among various chipsets employed by the DUTs in coordination with a standard tester configuration without need for reconfiguring or reprogramming of the tester. 
     Many of today&#39;s electronic devices use wireless technologies for both connectivity and communications purposes. Because wireless devices transmit and receive electromagnetic energy, and because two or more wireless devices have the potential of interfering with the operations of one another by virtue of their signal frequencies and power spectral densities, these devices and their wireless technologies must adhere to various wireless technology standard specifications. 
     When designing such wireless devices, engineers take extra care to ensure that such devices will meet or exceed each of their included wireless technology prescribed standard-based specifications. Furthermore, when these devices are later being manufactured in quantity, they are tested to ensure that manufacturing defects will not cause improper operation, including their adherence to the included wireless technology standard-based specifications. 
     For testing these devices following their manufacture and assembly, current wireless device test systems employ a subsystem for analyzing signals received from each device. Such subsystems typically include at least a vector signal generator (VSG) for providing the source signals to be transmitted to the device under test, and a vector signal analyzer (VSA) for analyzing signals produced by the device under test. The production of test signals by the VSG and signal analysis performed by the VSA are generally programmable so as to allow each to be used for testing a variety of devices for adherence to a variety of wireless technology standards with differing frequency ranges, bandwidths and signal modulation characteristics. 
     As part of the manufacturing of wireless communication devices, one significant component of production cost is costs associated with manufacturing tests. Typically, there is a direct correlation between the cost of test and the sophistication of the test equipment required to perform the test. Thus, innovations that can preserve test accuracy while minimizing equipment costs (e.g., increasing costs due to increasing sophistication of necessary test equipment, or testers) are important and can provide significant costs savings, particularly in view of the large numbers of such devices being manufactured and tested. 
     Accordingly, it would be desirable to have techniques for testing increasingly sophisticated DUTs with increasingly varied performance characteristics and requirements without also requiring increasingly sophisticated testers with similarly increasingly varied testing characteristics and requirements. 
     SUMMARY 
     In accordance with the presently claimed invention, a system and method are provided for testing a wireless data packet signal transceiver device under test (DUT) by using DUT control circuitry separate from a tester to access and execute test program instructions for controlling the DUT during testing with the tester. The test program instructions can be provided previously and stored for subsequent access and execution under control of the tester or an external control source, such a personal computer. Alternatively, the test program instructions can be provided by the tester or external control source immediately prior to testing, such as when beginning testing of a DUT with new or different performance characteristics or requirements. Accordingly, specialized testing of different DUTs while accounting for differences among various chipsets employed by the DUTs can be performed in coordination with a standard tester configuration without need for reconfiguring or reprogramming of the tester. 
     In accordance with one embodiment of the presently claimed invention, a system for testing a wireless data packet signal transceiver device under test (DUT) includes: a data packet signal path for communicating with a DUT to convey a transmit data packet signal from the DUT and a receive data packet signal to the DUT; a tester coupled to the data packet signal path to receive the transmit data packet signal and provide the receive data packet signal, and responsive to one or more test commands by providing one or more test control signals; a DUT control signal interface for communicating with the DUT to convey at least one DUT control signal to the DUT; and DUT control circuitry coupled between the tester and the DUT control signal interface, responsive to at least the one or more test control signals by executing a plurality of test program operations to provide the at least one DUT control signal, wherein the transmit data packet signal is responsive to at least one of the receive data packet signal and the at least one DUT control signal. 
     In accordance with another embodiment of the presently claimed invention, a method of testing a wireless data packet signal transceiver device under test (DUT) includes: receiving, with a tester, a transmit data packet signal from a DUT; transmitting, with the tester, a receive data packet signal to the DUT; responding, with the tester, to one or more test commands by providing one or more test control signals; and responding, with DUT control circuitry, to at least the one or more test control signals by executing a plurality of test program operations to provide at least one DUT control signal to the DUT, wherein the transmit data packet signal is responsive to at least one of the receive data packet signal and the at least one DUT control signal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts a conventional test environment for testing data packet transceivers. 
         FIG. 2  depicts a test environment for testing data packet transceivers in accordance with exemplary embodiments of the presently claimed invention. 
         FIG. 3  depicts a test program flow in accordance with exemplary embodiments of the presently claimed invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is of example embodiments of the presently claimed invention with references to the accompanying drawings. Such description is intended to be illustrative and not limiting with respect to the scope of the present invention. Such embodiments are described in sufficient detail to enable one of ordinary skill in the art to practice the subject invention, and it will be understood that other embodiments may be practiced with some variations without departing from the spirit or scope of the subject invention. 
     Throughout the present disclosure, absent a clear indication to the contrary from the context, it will be understood that individual circuit elements as described may be singular or plural in number. For example, the terms “circuit” and “circuitry” may include either a single component or a plurality of components, which are either active and/or passive and are connected or otherwise coupled together (e.g., as one or more integrated circuit chips) to provide the described function. Additionally, the term “signal” may refer to one or more currents, one or more voltages, or a data signal. Within the drawings, like or related elements will have like or related alpha, numeric or alphanumeric designators. Further, while the present invention has been discussed in the context of implementations using discrete electronic circuitry (preferably in the form of one or more integrated circuit chips), the functions of any part of such circuitry may alternatively be implemented using one or more appropriately programmed processors, depending upon the signal frequencies or data rates to be processed. Moreover, to the extent that the figures illustrate diagrams of the functional blocks of various embodiments, the functional blocks are not necessarily indicative of the division between hardware circuitry. 
     As discussed in more detail below, in accordance with embodiments of the presently claimed invention, interaction between a tester and a DUT can be controlled in such a way as to reduce latency and necessary volume of communications between the tester and the DUT, thereby reducing test time and, therefore, costs associated with test time. For example, communications latency can be reduced by enabling the tester to more rapidly transition between signal transmission and signal reception modes of operation, while communications volume can be minimized by reducing the number of control commands needed to flow from the tester to the DUT. 
     One technique for minimizing interaction between a tester and DUT involves using a single command from the tester to initiate transaction of multiple, predetermined tester data packets until a predetermined number of such tester data packets have been transmitted. (This has been disclosed in detail in U.S. patent application Ser. Nos. 11/422,475, 11/422,489 and 11/696,921, the contents of which are incorporated herein by reference.) Another technique involves using a predetermined sequence of test steps known to both the DUT and the tester to reduce the need for commands to be exchanged between the DUT and tester. (This has been disclosed in detail in U.S. patent application Ser. Nos. 11/279,778, 11/839,814, 11/839,788 and 11/839,828, the contents of which are incorporated herein by reference.) However, these sequencing techniques involving multiple tester data packets and sequencing of test steps require support on the part of the tester or DUT, or both, such as additional hardware, firmware or software (e.g., additional programming of test commands). For example, to support these time saving test techniques, the DUT might require firmware that is specific to its processing subsystem (e.g., its particular chipset), and one or more manufacturers of the integrated circuits may be required to support these techniques with specific driver functions. 
     These difficulties, however, can be avoided with the presently claimed invention, which enables multiple test data packet and test step sequencing techniques to be used without requiring special provisions to the DUT, and in most cases, to the tester as well. In accordance with exemplary embodiments, an external processing subsystem is used to control the DUT in coordination with the tester. This external subsystem can be designed to accommodate a variety of DUTs and their associated chipsets to support multiple test data packet and test step sequencing techniques, while requiring no modifications to the hardware or firmware of the DUT. 
     Referring to  FIG. 1 , a conventional testing environment for testing a wireless data packet transceiver device under test (DUT) includes the tester  12 , a DUT  14  (or, alternatively, multiple DUTs to be tested concurrently or sequentially, depending upon the tester configuration), and a controller  16  (e.g., a personal computer). As discussed above, a tester includes a data packet signal source  12   g  (typically in the form of a VSG) and a data packet signal receiver and analyzer  12   a  (typically in the form of a VSA). The tester can also include control circuitry  12   c  for performing various control functions in accordance with internally stored test programs or test commands or programs received from an external source (e.g., the controller  16 ). 
     The tester  12  and DUT  14  communicate via a signal path  13 . This signal path  13  is typically in the form of a conductive radio frequency (RF) signal path, such as a coaxial cable and connectors. However, this signal path  13  can also be in the form of a radiative signal path, such as that formed by the use of RF antennas (not shown) connected to the signal ports of the tester  12  and DUT  14  for radiating and receiving electromagnetic signals in accordance with well-known principles. 
     The controller  16  provides testing instructions and receives test data from the tester  12  and DUT  14  via signal interfaces  17   t ,  17   d , which are typically in the form of multiple-conductor cables. 
     As discussed above, such a testing environment can support sequencing of multiple test packets and test steps. However, as also discussed above, such support is achieved at the cost of modifications to hardware or firmware of at least the DUT  14 , and, in some cases, to the tester  12  as well. 
     Referring to  FIG. 2 , a testing environment  100  in accordance with exemplary embodiments of the presently claimed invention includes an external subsystem  102 ,  104 , which, as discussed above, operates in coordination with the tester  12  and includes any necessary hardware, firmware or software needed to support multiple test data packet and test step sequencing of the DUT  14  in accordance with the requirements of the DUT  14  chipset. 
     When testing the DUT  14 , the tester  12  sends data packet signals to the DUT  14  via the signal path  13 , and monitors responses received from the DUT  14 , e.g., in the form of acknowledgment signals (“ACK”) or other types of data packet signals. These responsive signals are received by the tester receiver circuitry  12   a  and analyzed, such as by measuring and comparing various physical signal characteristics (e.g., signal power, frequency, modulation type or bit-rate) against values specified in accordance with the signal standard in conformance with which the DUT  14  is designed to operate. 
     During such testing, coordination between the tester  12  and DUT  14  is necessary, and is typically done by issuing commands to the DUT  14  from the tester  12  (e.g., via the data packet signal interface  13 ) or in coordination with the tester  12 , such as by providing instructions to the DUT  14  from the controller  16  via the control signal interface  17   d . Accordingly, during a complete test sequence, numerous control commands will be required to be conveyed from the tester  12  or controller  16  to the DUT  14  during one or more time intervals in which no test measurements are performed by the tester  12  (with respect to data packet signals received from the DUT  14 ) but which nonetheless consume time. Hence, overall test time can be reduced if these times needed for control commands can be reduced in duration and/or number. 
     In general, reducing the number of control commands requires that one or more commands cover more than one testing event. For example, a typical command to the DUT  14  to prepare to receive a test data packet signal from the tester  12  covers one event, i.e., the sending of the test signal. A second command to query the DUT  14  as to whether the test signal was received correctly or not also covers one event. However, if the DUT  14  was pre-programmed to respond to a single command by receiving a predefined number of test data packets from the tester  12 , and automatically confirming that such test data packets were correctly received, that single original command could cover a potentially extensive sequence of testing events. 
     As a further example, if the DUT  14  and tester  12  operated in accordance with a previously agreed upon sequence of test steps to execute and, upon synchronization, began executing those test steps until all test steps were completed, or one test step had timed out, then that initial exchange of synchronization signals could cover an entire testing sequence, including both receive (RX) and transmit (TX) testing (from the perspective of the DUT  14 ) with test signals having predetermined physical characteristics (e.g., frequency, power, modulation type, bit-rate, etc.). Alternatively, the tester  12  and DUT  14  can transmit or receive data packets from one another until a control or responsive signal is received by the transmitting unit from the receiving unit indicating completion of that set of test steps and signaling that the transmitting unit can proceed to the next predefined operation. 
     In accordance with exemplary embodiments of the presently claimed invention, the external subsystem  102  is provided (e.g., programmed) with programs specifically matched to the DUT  14  and its chipsets, thereby ensuring that the specific characteristics and capabilities of the DUT  14  can be tested adequately using time-saving testing techniques such as multiple test data packet and test step sequencing techniques. This advantageously avoids the need for special preparation or customization of the DUT  14 , such as through expanded or customized hardware, firmware or modified or additional driver software. Accordingly, working in conjunction with the tester  12 , it is this external processing subsystem  102  (e.g., a microcontroller), rather than the DUT  14 , that is aware of and tasked with managing access to and execution of the test sequencing requirements. Hence, the testing speed and cost benefits of test sequencing can be achieved without requiring special preparations or modifications for the DUT  14  itself. 
     The DUT controller  102  communicates (e.g., by exchanging control signals acting as triggers or containing instructions or data) with the tester  12  via a control signal interface  103   t . Similarly, the DUT controller  102  communicates (e.g., by exchanging instructions and data) with the DUT  14  via another control signal interface  103   d . The instructions for the programs needed to control the DUT  14  during testing can be stored internally or externally in separate memory circuitry  104 , accessible via a memory interface  105 . These programs (e.g., DUT control instructions and signal parameter values) can be pre-programmed into the DUT controller  102  or memory  104 , or can be provided by the tester  12  (e.g., from the tester controller  12   c ), or provided by the external controller  16  directly to the memory  104  via another memory interface  117   m.    
     Initiation of the testing of the DUT  14  normally begins with the tester  12  instructing the DUT controller  102  to configure the DUT  14  for the testing sequence to be performed. In response, the DUT controller  102  accesses the appropriate program and provides the instructions and parameter data needed for such tests. Alternatively, the external controller  16  can instruct the DUT controller  102 , via a control interface  117   c , to configure the DUT  14  for testing. 
     Following reception of a start signal from the tester  12  via its interface  103   t , the DUT controller  102  instructs the DUT  14  to initiate a sequence of sending or receiving data packets until a predetermined number of data packets has been sent by the DUT  14 , or until the tester  12  informs the DUT controller  102  that testing operations have been completed (e.g., the tester  12  has transmitted all data packets required for the current test). 
     For example, in cases of a DUT TX signal measurement, the tester  12  would capture data packets transmitted from the DUT  14 , and when the desired data packets have been captured by the tester  12  it would signal the DUT controller  102  to terminate data packet transmission by the DUT  14  and proceed to the next test operation. Similarly, in the case of a DUT RX test, the tester  12  would signal the DUT  14 , via the DUT controller  102 , to begin receiving data packets via the signal path  13 , and when the desired number of data packets have been transmitted by the tester  12  to the DUT  14 , the tester  12  can instruct the DUT controller  102  to proceed to the next DUT test operation. Additionally, as needed, the DUT controller  102  can signal its readiness to the tester  12  via their signal interface  103   t . Hence, as can be seen by these examples, multiple data packets can be transmitted and received by the tester  12  and DUT  14  with a single command from the external controller  16  and a start signal from the tester  12 . As a result, communication and test flow control from the external controller  16  can be avoided and the tester  12  can control the flow of test operations based on pre-programmed test programs stored within and executed by the dedicated DUT controller  102 . 
     Referring to  FIG. 3 , in accordance with an exemplary embodiment, the program flow for testing using the environment of  FIG. 2  can proceed as follows. Following a start command  202  from the external controller  16  or tester  12 , the DUT controller  102  and DUT  14  are initialized, or “booted”,  204 . In the absence of the occurrence of an interrupt  209  (e.g., in the form of a command, request, or other type of signal from the tester  12 ), with the program index at zero, program flow  205  proceeds to determine whether or interrupt has occurred  208 . If no interrupt has occurred  209 , this step of checking for an interrupt  208  repeats until it is determined that an interrupt has occurred. 
     Program flow then continues to the next step where the index is incremented  210 , following which the next test command is executed  212  in accordance with the index value. Following this, it is determined whether the test flow has been completed  214 . If not  215 , the process of checking for interrupt  208 , incrementing the index  210  and executing the next test command  212  is repeated. If test flow has been completed, then test flow reverts to the beginning, to await the next start command  202 . 
     As a further alternative, the subsystem  102 ,  104  elements can be included as part of (e.g., internal to) the DUT  14 . For example, the controller  102  and memory  104  can be elements within the DUT  14  that, while providing functionality for the DUT  14  during its normal use, also provide functionality specific for and dedicated to the testing operations as set forth above. Still further alternatives include testing environments in which the tester  12  issues multiple types of commands, and in which the DUT  14  transmits signals (e.g., either self-initiated or in response to signals from the tester  12 ). 
     Various other modifications and alternations in the structure and method of operation of this invention will be apparent to those skilled in the art without departing from the scope and the spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. It is intended that the following claims define the scope of the present invention and that structures and methods within the scope of these claims and their equivalents be covered thereby.