MBM29LV008BA Просмотр технического описания (PDF) - Spansion Inc.

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MBM29LV008BA

FLASH MEMORY CMOS 8M (1M × 8) BIT

Spansion Inc. 

MBM29LV008TA/BA-70/90

The manufacturer and device codes may also be read via the command register, for instances when the

MBM29LV008TA/BA are erased or programmed in a system without access to high voltage on the A9 pin. The

command sequence is illustrated in “MBM29LV008TA/008BA Standard Command Definitions” in s DEVICE

BUS OPERATION. (Refer to “Autoselect Command”.)

Byte 0 (A0 = VIL) represents the manufacturer’s code (Fujitsu = 04h) and (A0 = VIH) represents the device identifier

code (MBM29LV008TA = 3Eh and MBM29LV008BA = 37h). These two bytes/words are given in

“MBM29LV008TA/008BA Sector Protection Verify Autoselect Codes” and “Expanded Autoselect Code Table” in

s DEVICE BUS OPERATION. All identifiers for manufactures and device will exhibit odd parity with DQ7 defined

as the parity bit. In order to read the proper device codes when executing the autoselect, A1 must be VIL. (See

“MBM29LV008TA/008BA Sector Protection Verify Autoselect Codes” and “Expanded Autoselect Code Table” in

s DEVICE BUS OPERATION.)

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

command 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 Waveforms for Alternate WE Controlled Program Operations” and “AC Waveforms for Alternate CE

Controlled Program Operations” in s TIMING DIAGRAM.

Sector Protection

The MBM29LV008TA/BA feature hardware sector protection. This feature will disable both program and erase

operations in any number of sectors (0 through 18). The sector protection feature is enabled using programming

equipment at the user’s site. The devices are shipped with all sectors unprotected. Alternatively, Fujitsu may

program and protect sectors in the factory prior to shiping the device.

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 = VIL. The sector addresses (A19, A18, A17, A16, A15, A14, and A13) should be set to

the sector to be protected. “Sector Address Tables (MBM29LV008TA) ” and “Sector Address Tables

(MBM29LV008BA) ” in s FLEXIBLE SECTOR-ERASE ARCHITECTURE define the sector address for each of

the nineteen (19) individual 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 addresses must be held constant during

the WE pulse. See “ (10) AC Waveforms for Sector Protection Timing Diagram” in s TIMING DIAGRAM and “

(5) Sector Protection Algorithm” in s FLOW CHART for sector 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 addresses (A19, A18, A17, A16, A15, A14, and A13) while

(A10, A6, A1, A0) = (0, 0, 1, 0) will produce a logical “1” code at device output DQ0 for a protected sector. Otherwise

the devices will read 00h for unprotected sector. In this mode, the lower order addresses, except for A0, A1, A6,

and A10 are DON’T CARES. Address locations with A1 = VIL are reserved for Autoselect manufacturer and device

codes.

It is also possible to determine if a sector is protected in the system by writing an Autoselect command. Performing

a read operation at the address location XX02h, where the higher order addresses (A19, A18, A17, A16, A15, A14,

and A13) are the desired sector address will produce a logical “1” at DQ0 for a protected sector. See

“MBM29LV008TA/008BA Sector Protection Verify Autoselect Codes” and “Expanded Autoselect Code Table”

in s DEVICE BUS OPERATION for Autoselect codes.

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