CY7C1325
Burst Sequences
This family of devices provide a 2-bit wrap-around burst
counter inside the SRAM. The burst counter is fed by A[1:0],
and can follow either a linear or interleaved burst order. The
burst order is determined by the state of the MODE input. A
LOW on MODE will select a linear burst sequence. A HIGH on
MODE will select an interleaved burst order. Leaving MODE
unconnected will cause the device to default to a interleaved
burst sequence.
Table 1. Counter Implementation for the Intel®
Pentium®/80486 Processor’s Sequence
First
Address
AX + 1, Ax
00
01
10
11
Second
Address
AX + 1, Ax
01
00
11
10
Third
Address
AX + 1, Ax
10
11
00
01
Fourth
Address
AX + 1, Ax
11
10
01
00
Table 2. Counter Implementation for a Linear Sequence
First
Address
AX + 1, Ax
00
01
10
11
Second
Address
AX + 1, Ax
01
10
11
00
Third
Address
AX + 1, Ax
10
11
00
01
Fourth
Address
AX + 1, Ax
11
00
01
10
Sleep Mode
The ZZ input pin is an asynchronous input. Asserting ZZ HIGH
places the SRAM in a power conservation “sleep” mode. Two
clock cycles are required to enter into or exit from this “sleep”
mode. While in this mode, data integrity is guaranteed. Ac-
cesses pending when entering the “sleep” mode are not con-
sidered valid nor is the completion of the operation guaran-
teed. The device must be deselected prior to entering the
“sleep” mode. CE1, CE2, CE3, ADSP, and ADSC must remain
inactive for the duration of tZZREC after the ZZ input returns
LOW.
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