PUMA2E4001-12E Mosaic Semiconductor, PUMA2E4001-12E Datasheet - Page 10

• Manufacturer Part Number: PUMA2E4001-12E
• Description: 128K x 32 EEPROM Module
• Manufacturer: Mosaic Semiconductor

ISSUE 4.2 : November 1998
Selecting the software data protection mode requires the host system to precede datawrite operations by a series
of three write operations to three specfic addresses. The three byte sequence opens the page write window
enabling the host to write from from 1 to 128 bytes of data. Once the page load cycle has been completed, the device
will automatically be returned to the data protected state
Regardless of wheather the device has been protected or not, once the software data protected aglorithm is used
and the data is written, the device will automatically disable further writes unless another command is issued to
cancel it. If no further commands are issued the device will be write protected during power-down and any
subsequent power-up.
Notes:
(1) Data Format I/O7-I/O0 (Hex);
(2) Enable Write Protect state will be initiated at end of write even if no other data is loaded.
(3) Disable Write Protect state will be initiated at end of write period even if no other data is loaded.
(4) 1 to 128 bytes of data may be loaded.
Software Algorithms
Software Data Protection Algorithm
Once initiated, this sequence of write operations should not be interrupted.
LAST BYTE / WORD
LAST ADDRESS
LOAD DATA XX
ANY ADDRESS (4)
ADDRESS 5555
ADDRESS 2AAA
ADDRESS 5555
LOAD DATA AA
LOAD DATA A0
LOAD DATA 55
TO
TO
TO
TO
TO
10
WRITES
ENABLED (2)
ENTER DATA
PROTECT
STATE
PUMA 2/67/77E4001/A - 12/15/20