A d v a n c e I n f o r m a t i o n
Write Protect (WP#)
The device features a hardware protection option using a write protect pin that
prevents programming or erasing, regardless of the state of the sector’s Persis-
tent or Dynamic Protection Bits. The WP# pin is associated with the two
outermost 8Kbytes sectors in the 75% bank. The WP# pin has no effect on any
other sector. When WP# is taken to V , programming and erase operations of the
IL
two outermost 8 Kbytes sectors in the 75% bank are disabled. By taking WP#
back to V , the two outermost 8 Kbytes sectors are enabled for program and
IH
erase operations, depending upon the status of the individual sector Persistent or
Dynamic Protection Bits. If either of the two outermost sectors Persistent or Dy-
namic Protection Bits are programmed, program or erase operations are
inhibited. If the sector Persistent or Dynamic Protection Bits are both erased, the
two sectors are available for programming or erasing as long as WP# remains at
V . The user must hold the WP# pin at either V or V during the entire pro-
IH
IH
IL
gram or erase operation of the two outermost sectors in the 75% bank.
SecSi™ (Secured Silicon) Sector Protection
The SecSi Sector is a 256-byte flash memory area that is either programmable
at the customer or by AMD at the request of the customer. The SecSi Sector Entry
command enables the host system to address the SecSi Sector for programming
or reading. The SecSi sector address range is 00000h–0003Fh (ordering option
00) or FFFC0h–FFFFFh (ordering option 01). The address range 00040h–007FFh
(ordering option 01) or FF800h–FFFBFh (ordering option 01) returns invalid data
when addressed with the SecSi Sector enabled.
The device allows Simultaneous Read/Write operation while the SecSi Sector is
enabled. However, there are a number of restrictions associated with Simulta-
neous Read/Write operations and device operation when the SecSi Sector is
enabled:
1) The SecSi Sector is not available for reading while the Password Unlock, any
PPB program/erase operation, or Password programming are in progress. Read-
ing to any location in the small (25%) sector will return the status of these
operations until these operations have completed execution.
2) Writing the corresponding DYB associated with the overlaid bootblock sector
results in the DYB NOT being updated. This is only accomplished when the SecSi
sector is not enabled.
3) Reading the corresponding DYB associated with the overlaid bootblock sector
results in reading invalid data when the PPB Lock/DYB Verify command is issued.
This function is only accomplished when the SecSi Sector is not enabled.
4) All commands are available for execution when the SecSi Sector is enabled ex-
cept the following list. Issuing the following commands while the SecSi Sector is
enabled results in the command being ignored.
All Unlock Bypass commands
CFI
Accelerated Program
Program and Sector Erase Suspend
Program and Sector Erase Resume
5) Executing the Sector Erase command is permitted when the SecSi Sector is
enabled, however, there is no provision for erasing the SecSi Sector with the Sec-
tor Erase command, regardless of the protection status. The Sector Erase
command will erase all other sectors when the SecSi Sector is enabled.
32
S29CD032G
30606B0 March 22, 2004
SPANSION [ SPANSION ]
