D A T A S H E E T
tor Exit command return the device to normal opera-
DYB Write Command
tion.
The DYB Write command is used for setting the DYB,
which is a volatile bit that is cleared at hardware reset.
There is one DYB per sector. If the PPB is set, the sec-
tor is protected regardless of the value of the DYB. If
the PPB is cleared, setting the DYB to a 1 protects the
sector from programs or erases. Since this is a volatile
bit, removing power or resetting the device will clear
the DYBs. Writing Read/Reset command returns the
device to normal operations.
PPB Lock Bit Status Command
The programming of the PPB Lock Bit for a given sec-
tor can be verified by writing a PPB Lock Bit status ver-
ify command to the device. Read/Reset and SecSi
Sector Exit return the device to normal operation.
DYB Status Command
The programming of the DYB for a given sector can be
verified by writing a DYB Status command to the de-
vice. Writing SecSi Sector Exit command returns the
device to normal operation.
PPB Status Command
The programming of the PPB for a given sector can be
verified by writing a PPB status verify command to the
device. Writing Read/Reset command and SecSi Sec-
May 10, 2006 27024B3
Am29BDS128H/Am29BDS640H
45
SPANSION [ SPANSION ]
