CAT24C44 Catalyst Semiconductor, CAT24C44 Datasheet - Page 6

• Manufacturer Part Number: CAT24C44
• Description: 256-Bit Serial Nonvolatile CMOS Static RAM
• Manufacturer: Catalyst Semiconductor

WREN/WRDS
The CAT24C44 powers up in the program disable state
(the “write enable latch” is reset). Any programming
after power-up or after a WRDS (RAM write/E
store disable) instruction must first be preceded by the
WREN (RAM write/E
Once writing/storing is enabled, it will remain enabled
until power to the device is removed, the WRDS instruc-
tion is sent, or an E
Figure 3. Read Cycle Timing
Figure 4. Write Cycle Timing
Doc. No. 25019-0A 2/98 N-1
DO
CE
CE
SK
SK
DI
DI
SK CYCLE #
2
2
PROM store has been executed
PROM store enable) instruction.
V IH
6
x
t DS
t CES
t SKH
HIGH-Z
7
1
1/F SK
t DH
2
PROM
t SKL
t PD
8
2
6
(STO). The WRDS (write/store disable) can be used to
disable all CAT24C44 programming functions, and will
prevent any accidental writing to the RAM, or storing to
the E
Data can be read normally from the CAT24C44 regard-
less of the “write enable latch” status.
t CEH
D0
9
n
2
PROM.
t PD
D1
10
t CDS
Dn
11
t Z
HIGH-Z
5157 FHD F04
5157 FHD F05