S29CD-J_12 SPANSION [SPANSION], S29CD-J_12 Datasheet - Page 50

• Manufacturer Part Number: S29CD-J_12
• Manufacturer: SPANSION [SPANSION]

10. Secured Silicon Sector Flash Memory Region
50
The Secured Silicon Sector provides an extra Flash memory region that enables permanent part identification
through an Electronic Serial Number (ESN). The Secured Silicon Sector is a 256-byte flash memory area that
is either programmable at the customer, or by Spansion at the request of the customer. See
the Secured Silicon Sector address ranges.
All Secured Silicon reads outside of the 256-byte address range return invalid data.
The device allows Simultaneous Read/Write operation while the Secured Silicon Sector is enabled. However,
several restrictions are associated with Simultaneous Read/Write operation and device operation when the
Secured Silicon Sector is enabled:
Issuing the above commands while the Secured Silicon Sector is enabled results in the command being
ignored.
1. The Secured Silicon Sector is not available for reading while the Password Unlock, any PPB
2. Programming the DYB associated with the overlaid boot-block sector results in the DYB NOT being
3. Reading the DYB associated with the overlaid boot-block sector when the PPB Lock/DYB Verify
4. All commands are available for execution when the Secured Silicon Sector is enabled, except the
5. It is valid to execute the Sector Erase command on any sector other than the Secured Silicon
6. Executing the Chip Erase command is permitted when the Secured Silicon Sector is enabled. The
7. Executing the Secured Silicon Sector Entry command during program or erase suspend mode is
8. Address range 00040h–007FFh for the top bootblock, and FF00h–FFF7Fh return invalid data
9. The Secured Silicon Sector Entry command is allowed when the device is in either program or
program/erase operation, or Password programming are in progress. Reading to any location in
the small bank will return the status of these operations until these operations have completed
execution.
updated. This occurs only when the Secured Silicon sector is not enabled.
command is issued, causes the read command to return invalid data. This function occurs only
when the Secured Silicon Sector is not enabled.
following:
Sector when the Secured Silicon Sector is enabled. However, it is not possible to erase the
Secured Silicon Sector using the Sector Erase Command, as it is a one-time programmable (OTP)
area that can not be erased.
Chip Erase command erases all sectors in the memory array, except for sector 0 in top-boot block
configuration, or sector 45 in bottom-boot block configuration. The Secured Silicon Sector is a one-
time programmable memory area that cannot be erased.
allowed. The Sector Erase/Program Resume command is disabled when the Secured Silicon
sector is enabled; the user cannot resume programming of the memory array until the Exit Secured
Silicon Sector command is written.
when addressed with the Secured Silicon sector enabled.
erase suspend modes. If the Secured Silicon sector is enabled, the program or erase suspend
command is ignored. This prevents resuming either programming or erasure on the Secured
a. Any Unlock Bypass command
b. CFI
c. Accelerated Program
d. Program and Sector Erase Suspend
e. Program and Sector Erase Resume
Ordering Option
Bottom Boot
Top Boot
S29CD-J and S29CL-J Flash Family
Table 10.1 Secured Silicon Sector Addresses
D a t a
Sector Size (Bytes)
256
256
S h e e t
S29CD-J_CL-J_00_B7 October 11, 2012
00000h-0003Fh (16 Mb and 32 Mb)
FFFC0h–FFFFFh (32 Mb)
7FFC0h–7FFFFh (16 Mb)
Address Range
Table 10.1
for