RC28F640P33B85 Numonyx, RC28F640P33B85 Datasheet - Page 67

• Manufacturer Part Number: RC28F640P33B85
• Description: Numonyx? Strataflash Embedded Memory
• Manufacturer: Numonyx

Numonyx™ StrataFlash
.
Figure 32: Protection Register Map
11.4.8.1
November 2007
Order Number: 314749-05
The first 128-bit Protection Register is comprised of two 64-bit (8-word) segments. The
lower 64-bit segment is pre-programmed at the Numonyx factory with a unique 64-bit
number. The other 64-bit segment, as well as the other sixteen 128-bit Protection
Registers, are blank. Users can program these registers as needed. When programmed,
users can then lock the Protection Register(s) to prevent additional bit programming
(see
The user-programmable Protection Registers contain one-time programmable (OTP)
bits; when programmed, PR 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.
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
Figure 32, “Protection Register Map” on page
®
Embedded Memory (P33)
0x109
0x102
0x8A
0x91
0x89
0x88
0x85
0x84
0x81
0x80
15 14 13 12 11 10 9
15 14 13 12 11 10 9
128-bit Protection Register 16
128-bit Protection Register 1
128-Bit Protection Register 0
(Factory-Programmed)
(User-Programmable)
(User-Programmable)
(User-Programmable)
Lock Register 1
64-bit Segment
64-bit Segment
Lock Register 0
8
8
Section 9.6, “Device Command Bus Cycles” on
7
7
6
6
5
5
4
4
3
3
2
2
1
1
0
0
67).
Datasheet
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