A d v a n c e I n f o r m a t i o n
Locking, or Persistent Protection Bits. Unlike devices that have the Single High
Voltage Sector Unprotect/Protect feature, the device has the standard two-cycle
unlock followed by 60h, which places the device into non-volatile bit program or
erase mode. Once the mode is entered, the specific non-volatile bit status is read
on DQ0. 4 shows a typical flow for programming the non-volatile bit and 5 shows
a typical flow for erasing the non-volatile bits. The SecSi Sector Protection, Pass-
word Locking, Persistent Sector Protection Mode Locking bits are not erasable
after they are programmed. However, the PPBs are both erasable and program-
mable (depending upon device security).
Unlike Single High Voltage Sector Protect/Unprotect, the A6 pin no longer func-
tions as the program/erase selector nor the program/erase margin enable.
Instead, this function is accomplished by issuing the specific command for either
program (68h) or erase (60h).
In asynchronous mode, the DQ6 toggle bit indicates whether the program or
erase sequence is active. (In synchronous mode, ADV# indicates the status.) If
the DQ6 toggle bit toggles with either OE# or CE#, the non-volatile bit program
or erase operation is in progress. When DQ6 stops toggling, the value of the non-
volatile bit is available on DQ0.
60
S29CD032G
30606B0 March 22, 2004
SPANSION [ SPANSION ]
