CAT33C804A Datasheet, PDF (13/14 Pages) Catalyst Semiconductor – 4K-Bit Secure Access Serial E2PROM

Preliminary
CAT33C804A
1000 0011
Override the memory protection for the next instruction.
READ Read Memory
1100 1001 [A15–A8] [A7–A0] (x8 organization)
1100 1001 [A7–A0] (x16 organization)
Output the contents of the addressed memory location
to the serial port.
WRITE Write Memory
1100 0001 [A15–A8] [A7–A0] [D7–D0] (x8 organization)
1100 0001 [A7–A0] [D15–D8] [D7–D0] (x16 organization)
Write the 8-bit or 16-bit data to the addressed memory
location. After the instruction, address, and data have
been entered, the self-timed program/erase cycle will
start. The addressed memory location will be erased
before data is written. The DO pin may be used to output
the RDY/BUSY status by having previously entered the
ENBSY instruction. During the program/erase cycle, DO
will output a LOW for BUSY during this cycle and a HIGH
for READY after the cycle has been completed.
ERASE Clear Memory
1100 0000 [A15–A8] [A7–A0] (x8 organization)
1100 0000 [A7–A0] (x16 organization)
Erase data in the specified memory location (set memory
to “1”). After the instruction and the address have been
entered, the self-timed clear cycle will start. The DO pin
may be used to output the RDY/BUSY status by having
previously entered the ENSBY instruction. During the
clear cycle, DO will output a LOW for BUSY during this
cycle and a HIGH for ready after the cycle has been
completed.
ERAL Clear All
1000 1001
1000 1001
Erase the data of all memory locations (all cells set to
“1”). For protection against inadvertent chip clear, the
ERAL instruction is required to be entered twice.
Figure 16. WRAL Timing (x8 Format)
CS
OP CODE
OP CODE
OP0–OP7
OP0–OP7
DI
DO
HIGH-Z
DATA
D0–D7
tEW
BUSY(1)
NEXT INSTRUCTION
33C804 F17
Figure 17. WRAL Timing (x16 Format)
CS
OP CODE
OP CODE
DATA
DATA
OP0–OP7
OP0–OP7
D8–D15
D0–D7
DI
NEXT INSTRUCTION
tEW
DO
HIGH-Z
BUSY(1)
33C804 F18
Note:
(1) DO becomes low to indicate busy status if ENBSY was previously executed. If ENBSY was not previously executed, DO will be in the
High-Z condition.
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Doc. No. 25044-00 2/98