Patent GB-1452685-A (GB)
Title: Interleaved main storage and data processing system
IPC: G11C7/00
Filed: 1974-03-19
Abstract: 1452685 Storage systems AMDAHL CORP 19 March 1974 [2 April 1973] 12170/74 Heading G4C In a data processing system the main storage is arranged in first and second groups of semiconductor chips, the first group being accessed whilst the second group is in a charging period and the second group being accessed whilst the first group is in a charging period. The store comprises a plurality of even and odd cards (830, 831), Fig. 4 (not shown) there being two cards (AC, BD) associated with each data bit position (E0-E63, 00-063). Each card comprises an 8 X 8 chip array, one card, 830, being shown in Fig. 5, there being similarly addressed chips in the upper and lower half of each array Fig. 7 (not shown) so that 4 data bits are accessed at one time. The address bits are alternately fed to even and odd address registers (871, 871'), Fig. 6 (not shown). The 6 high order bits 21-26 are decoded to derive row select signals (860, 861, 860', 861') for rows A-D or S-V, column select signals (863, 864, 863', 864') for columns E-H or W-Z and group select signals (856, 857, 856', 857') to select modules LM0, LM2 (on even cards) LM1, LM3 (on odd cards), modules LM2, LM having rows and columns A-H and modules LM2, LM3 having rows and columns S-Z. This results in 2 of the 64 chips being selected (e.g. chips AE), Fig. 7 (not shown). The low order address bits 11-20 are fed to row and column decoders (897, 898), Fig. 9 (not shown) of each MOS chip, the decoders of the addressed chip being enabled by the row and column select signals to address one of 1024 storage locations. The information transmitted to and from the store comprises 64 data bits, 9 error correcting bits and 8 key bits. In operation at ¢ clock pulse intervals, incoming 64 bit data is transferred along registers (818- 821), Fig. 3 (not shown) so that after 2¢ clock cycles a control signal latches the first three 64 bit data bytes into input registers (822, 823, 824) for the store. The next control signal transmits a fourth byte directly from the input bus into a register (825). Subsequently two sets of 9 error correcting bits are latched into registers (826, 827). To store the data a write signal is generated with an address signal, each address corresponding to four 64 bit groups of data. The address results in either an even or odd array being selected and for an even array a first signal (856) is active for time interval t<SP>0</SP>-t<SP>7</SP> and a second signal (857) is active for time intervals t<SP>6</SP>-t<SP>13</SP> (for an odd array the corresponding times are t<SP>3</SP>-t<SP>10</SP> and t<SP>9</SP>-t<SP>16</SP>). This enables one group of memory chips to be charged whilst the other group are being accessed and discharged. During times t<SP>5</SP>-t<SP>6</SP> four data bits are latched into each card of the even array i.e. 256 bits are simultaneously stored, 256 bits being similarly stored in the odd array between times t<SP>8</SP>-t<SP>9</SP>. Read out is effected sequentially from the even and odd arrays, 64 data lines have four bits of data time-multiflexed to permit the read out of 256 bits.