MBM29DL32XTE/BE80/90
• Write
Device erasure and programming are accomplished via the command register. The contents of the register serve
as inputs to the internal state machine. The state machine outputs dictate the function of the device.
The command register itself does not occupy any addressable memory location. The register is a latch used to
store the commands, along with the address and data information needed to execute the command. The com-
mand register is written by bringing WE to VIL, while CE is at VIL and OE is at VIH. Addresses are latched on the
falling edge of WE or CE, whichever happens later; while data is latched on the rising edge of WE or CE,
whichever happens first. Standard microprocessor write timings are used.
Refer to AC Write Characteristics and the Erase/Programming Waveforms for specific timing parameters.
• Sector Group Protection
The MBM29DL32XTE/BE feature hardware sector group protection. This feature will disable both program and
erase operations in any combination of twenty five sector groups of memory. (See “Sector Group
Addresses (MBM29DL32XTE) (Top Boot Block) ” and “Sector Group Addresses (MBM29DL32XBE) (Bottom
Boot Block) ” in “■ FLEXIBLE SECTOR-ERASE ARCHITECTURE”) . The sector group protection feature is
enabled using programming equipment at the user’s site. The device is shipped with all sector groups unpro-
tected.
To activate this mode, the programming equipment must force VID on address pin A9 and control pin OE, (suggest
VID = 11.5 V) , CE = VIL and A6 = A0 = VIL, A1 = VIH. The sector group addresses (A20, A19, A18, A17, A16, A15, A14,
A13, and A12) should be set to the sector to be protected. “Sector Address Table (MBM29DL322TE) ”, “Sector
Address Table (MBM29DL322BE) ”, “Sector Address Table (MBM29DL323TE) ”, “Sector Address Table
(MBM29DL323BE) ”, “Sector Address Table (MBM29DL324TE) ” and “Sector Address Table (MBM29DL324
BE) ” in “■ FLEXIBLE SECTOR-ERASE ARCHITECTURE” define the sector address for each of the seventy
one (71) individual sectors, and “Sector Group Addresses (MBM29DL32XTE) (Top Boot Block) ” and “Sector
Group Addresses (MBM29DL32XBE) (Bottom Boot Block) ” in “■ FLEXIBLE SECTOR-ERASE ARCHITEC-
TURE” define the sector group address for each of the twenty five (25) individual group sectors. Programming
of the protection circuitry begins on the falling edge of the WE pulse and is terminated with the rising edge of
the same. Sector group addresses must be held constant during the WE pulse. See “Sector Group Protection
Timing Diagram” in “■ TIMING DIAGRAM” and “Sector Group Protection Algorithm” in “■ FLOW CHART” for
sector group protection waveforms and algorithm.
To verify programming of the protection circuitry, the programming equipment must force VID on address pin A9
with CE and OE at VIL and WE at VIH. Scanning the sector group addresses (A20, A19, A18, A17, A16, A15, A14, A13,
and A12) while (A6, A1, A0) = (0, 1, 0) will produce a logical “1” code at device output DQ0 for a protected sector.
Otherwise the device will produce “0” for unprotected sector. In this mode, the lower order addresses, except
for A0, A1, and A6 are DON’T CARES. Address locations with A1 = VIL are reserved for Autoselect manufacturer
and device codes. A-1 requires to apply to VIL on byte mode.
It is also possible to determine if a sector group is protected in the system by writing an Autoselect command.
Performing a read operation at the address location XX02h, where the higher order addresses (A20, A19, A18, A17,
A16, A15, A14, A13, and A12) are the desired sector group address will produce a logical “1” at DQ0 for a protected
sector group. See “MBM29DL322/323/324TE/BE Sector Group Protection Verify Autoselect Codes Tables”,
“Extended Autoselect Code Tables” in “■ DEVICE BUS OPERATION” for Autoselect codes.
• Temporary Sector Group Unprotection
This feature allows temporary unprotection of previously protected sector groups of the MBM29DL32XTE/BE
devices in order to change data. The Sector Group Unprotection mode is activated by setting the RESET pin to
high voltage (VID) . During this mode, formerly protected sector groups can be programmed or erased by selecting
the sector group addresses. Once the VID is taken away from the RESET pin, all the previously protected sector
groups will be protected again. Refer to “Temporary Sector Group Unprotection Timing Diagram” in “■ TIMING
DIAGRAM” and “Temporary Sector Group Unprotection Algorithm” in “■ FLOW CHART”.
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SPANSION [ SPANSION ]
