tions while they are in progress, thus making the
SecSi sector unavailable for reading. If the SecSi sec-
tor is enabled while the DYB command is issued, the
DYB for the overlayed sector is NOT updated. Read-
ing the DYB status using the PPB Lock Bit/DYBDYB
verify command when the SecSi sector is enabled re-
turns invalid data.
SecSi Sector Entry Command
The SecSi Sector Entry command enables the SecSi
(OTP) sector to overlay the 8 KB outermost sector in
the small (25%) bank. The SecSi sector overlays
00000h–0003Fh for the top bootblock configuration
and 7FFC0h–7FFFFh for the bottom bootblock confiu-
ration. Address range 00040h–007FFh for the top
bootblock and 7F800h–7FFBFh return invalid data
when addressed with the SecSi sector enabled. The
following commands are permitted after issuing the
SecSi Sector Entry command:
Password Program Command
The Password Program Command permits program-
ming the password that is used as part of the hard-
ware protection scheme. The actual password is
64-bits long. Depending upon the state of the WORD#
pin, multiple Password Program Commands are re-
quired. For a x16 bit data bus, 4 Password Program
commands are required to program the password. For
a x32 bit data bus, 2 Password Program commands
are required. The user must enter the unlock cycle,
password program command (38h) and the program
address/data for each portion of the password when
programming. There are no provisions for entering the
2-cycle unlock cycle, the password program com-
mand, and all the password data. There is no special
addressing order required for programming the pass-
word. Also, when the password is undergoing pro-
gramming, Simultaneous Operation is disabled. Read
operations to any memory location will return the pro-
gramming status. Once programming is complete, the
user must issue a Read/Reset command to return the
device to normal operation. Once the Password is
written and verified, the Password Mode Locking Bit
must be set in order to prevent verification. The Pass-
word Program Command is only capable of program-
ming “0”s. Programming a “1” after a cell is
programmed as a “0” results in a time-out by the Em-
bedded Program Algorithm™ with the cell remaining
as a “0”. The password is all F’s when shipped from
the factory. All 64-bit password combinations are valid
as a password.
1. Autoselect
2. Password Program (x16 and x32)
3. Password Verify
4. Password Unlock (x16 and x32)
5. Read/Reset
6. Program
7. Chip and Sector Erase
8. SecSi Sector Protection Bit Program
9. PPB Program
10.All PPB Erase
11.PPB Lock Bit Set
12.DYB Write
13.DYB/PPB/PPB Lock Bit Verify
14.Security Reset
15.Configuration Register Write
16.Configuration Register Read
The following commands are unavailable when the
SecSi sector is enabled. Issuing the following com-
mands while the SecSi sector is enabled results in the
command being ignored.
1. Unlock Bypass
2. CFI
Password Programming is permitted if the SecSi sec-
tor is enabled.
3. Accelerated Program
4. Program and Sector Erase Suspend
5. Program and Sector Erase Resume
Password Verify Command
The Password Verify Command is used to verify the
Password. The Password is verifiable only when the
Password Mode Locking Bit is not programmed. If the
Password Mode Locking Bit is programmed and the
user attempts to verify the Password, the device will
always drive all F’s onto the DQ data bus.
The SecSi Sector Entry command is allowed when the
device is in either program or erase suspend modes. If
the SecSi sector is enabled, the program or erase sus-
pend command is ignored. This prevents resuming ei-
ther programming or erasure on the SecSi sector if the
overlayed sector was undergoing programming or era-
sure. The host system must ensure that the device
resume any suspended program or erase opera-
tion after exiting the SecSi sector.
The Password Verify command is permitted if the
SecSi sector is enabled. Also, the device will not oper-
ate in Simultaneous Operation when the Password
Verify command is executed. Only the password is re-
turned regardless of the bank address. The lower two
address bits (A0:A-1) are valid during the Password
Executing any of the PPB program/erase commands,
or Password Unlock command results in the small
bank (25% bank) returning the status of these opera-
June 7, 2006
Am29BDD160G
41
SPANSION [ SPANSION ]
