X46402 Datasheet, PDF (10/23 Pages) Xicor Inc. – Dual Voltage CPU Supervisor with 64K Password Protected EEPROM

X46402
Preliminary Information
PROGRAM OPERATIONS
Password Protected Array Programming
The password protected memory array write or OTP
write requires issuing an 8-bit Password Write command
followed by the password, password ACK command, the
address and then the data bytes transferred as illustrated
in Figure 10. Up to 64 bytes (or more) may be trans-
ferred. Sending more than 64 bytes results in data wrap-
ping and over-writing previous data. After the last byte to
be transferred is acknowledged, a stop condition is
issued which starts the nonvolatile write cycle.
Non-Password Protected Array Programming
The non-password protected memory array program
mode requires issuing the 8-bit No-Password Write com-
mand followed by the address and then the data bytes
transferred as illustrated in Figure 11. Up to 64 bytes (or
more) may be transferred. Sending more than 64 bytes
results in data wrapping and over-writing previous data.
After the last byte to be transferred is acknowledged a
stop condition is issued which starts the nonvolatile write
cycle.
Figure 10. Password Protected Array Programming (Memory and OTP arrays)
SDA _S
Password
COMMAND
Write
Password
7
Write
Password
0
Wait t_WC
OR
Repeated
ACK Polling
Command
If ACK, Then
Password Matches
ACK POLLING
COMMAND
S
Data 0
...
Data 63
Wait t_WC
S _{Data ACK Polling}
Figure 11. Non-Password Protected Array Programming (Memory array only)
SDA _S
No Password
COMMAND
Data 0
...
Data 63
Wait t_WC
S _{Data ACK}
Polling
10