128Mb, 256Mb, 512Mb, 1Gb StrataFlash Memory
One-Time Programmable Operations
One-Time Programmable Operations
The device contains sixteen 128-bit one-time programmable (OTP) blocks, two 64-bit
OTP blocks, and two 16-bit OTP lock registers. OTP lock register 0 is used for locking
OTP blocks 0 and 1 (two 64-bit blocks), and OTP lock register 1 is used for locking OTP
blocks 2 through 17 (sixteen 128-bit blocks).
Each block contains OTP bits that are factory set to 1 and can only be programmed from
1 to 0; OTP block bits cannot be erased from 0 back to 1. This feature makes the OTP
blocks particularly useful for implementing system-level security schemes, permanent-
ly storing data, or storing fixed system parameters.
OTP block 0 is pre-programmed with a unique 64-bit value and locked at the factory.
OTP block 1 contains all 1s and is user-programmable. OTP blocks 1 through 16 contain
all 1s and are user-programmable.
Each OTP block can be accessed multiple times to program individual bits, as long as
the block remains unlocked. When a lock register bit is programmed, the associated
OTP block can only be read—it can no longer be programmed.
OTP lock register bits lock out subsequent programming of the corresponding OTP
block. Each OTP block can be locked by programming its corresponding lock bit to 0. As
long as an OTP block remains unlocked (that is, its lock bit = 1), any of its remaining 1
bits can be programmed to 0.
Note: Once an OTP block is locked, it cannot be unlocked. Attempts to program a
locked OTP block will fail with error bits set. Additionally, because the lock register bits
themselves are OTP, when programmed, lock register bits cannot be erased. Therefore,
when an OTP block is locked, it cannot be unlocked.
Table 29: Program OTP Area Command Bus Cycles
Setup WRITE Cycle
Address Bus
Device address
Setup WRITE Cycle Confirm WRITE Cycle Confirm WRITE Cycle
Command
Data Bus
Address Bus
Data Bus
PROGRAM OTP AREA
00C0h
OTP register address
Register data
PDF: 09005aef8448483a
128_256_512_65nm_g18.pdf - Rev. F 8/11 EN
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