X68257 Datasheet, PDF (4/14 Pages) Xicor Inc. – E2 Micro-Peripheral

X68257
MODE SELECTION
CE
E
R/W
Mode
I/O
Power
VSS
LOW
HIGH
HIGH
X
X
HIGH
X
X
HIGH
LOW
Standby
Standby
Read
Write
High Z
High Z
D_OUT
DIN
Standby (CMOS)
Standby (TTL)
Active
Active
6539 PGM T02.2
PAGE WRITE OPERATION
Regardless of the microcontroller employed, the X68257
supports page mode write operations. This allows the
microcontroller to write from 1 to 128 bytes of data to the
X68257. Each individual write within a page write opera-
tion must conform to the byte write timing requirements.
The rising edge of E starts a timer delaying the internal
programming cycle 100µs. Therefore, each successive
write operation must begin within 100µs of the last byte
written. The following waveforms illustrate the sequence
and timing requirements.
Page Write Timing Sequence for E Controlled Operation
OPERATION
CE
AS
A/D0–A/D7
A8–A14
E
BYTE 0
AIN DIN
An
BYTE 1
AIN DIN
An
BYTE 2
LAST BYTE
READ (1)(2)
AIN DIN
An
AIN DIN
An
AIN DIN
An
AFTER tWC READY FOR
NEXT WRITE OPERATION
AIN
ADDR
AIN
Next Address
R/W
tBLC
tWC
Note: (1) For each successive write within a page write cycle A₇–A₁₄ must be the same.
6539 FHD F07.1
4