306666-11 Datasheet, PDF (67/99 Pages) Numonyx B.V – Numonyx StrataFlash Embedded Memory

P30
The user-programmable Protection Registers contain one-time programmable (OTP)
bits; when programmed, register bits cannot be erased. Each Protection Register can
be accessed multiple times to program individual bits, as long as the register remains
unlocked.
Each Protection Register has an associated Lock Register bit. When a Lock Register bit
is programmed, the associated Protection Register can only be read; it can no longer be
programmed. Additionally, because the Lock Register bits themselves are OTP, when
programmed, Lock Register bits cannot be erased. Therefore, when a Protection
Register is locked, it cannot be unlocked.
.
Figure 31: Protection Register Map
0x109
128-bit Protection Register 16
(User-Programmable)
0x102
0x91
128-bit Protection Register 1
(User-Programmable)
0x8A
Lock Register 1
0x89 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0x88
0x85
0x84
0x81
64-bit Segment
(User-Programmable)
128-Bit Protection Register 0
64-bit Segment
(Factory-Programmed)
Lock Register 0
0x80 ^{15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0}
13.3.1
Reading the Protection Registers
The Protection Registers can be read from any address. To read the Protection Register,
first issue the Read Device Identifier command at any address to place the device in the
Read Device Identifier state (see Section 9.2, “Device Commands” on page 45). Next,
perform a read operation using the address offset corresponding to the register to be
read. Table 33, “Device Identifier Information” on page 70 shows the address offsets of
the Protection Registers and Lock Registers. Register data is read 16 bits at a time.
November 2007
Order Number: 306666-11
Datasheet
67