M29F002 データシートの表示（PDF） - Fujitsu

部品番号

コンポーネント説明

メーカー

M29F002

2M (256K X 8) BIT FLASH MEMORY

Fujitsu 

MBM29F002TC-55/-70/-90/MBM29F002BC-55/-70/-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

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 Write Characteristics and the Erase/Programming Waveforms for specific timing parameters.

Sector Protection

The MBM29F002TC/BC features hardware sector protection. This feature will disable both program and erase

operations in any number of sectors (0 through 6). The sector protection feature is enabled using programming

equipment at the user's site. The device is shipped with all sectors unprotected.

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. The sector addresses (A13, A14, A15, A16, and A17) should be set to the sector to be

protected. Tables 4 and 5 define the sector address for each of the seven (7) 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 figures 14 and 21 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 (A13, A14, A15, A16, and A17) 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

device will produce 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 (A13, A14, A15, A16, and A17)

are the desired sector address will produce a logical “1” at DQ0 for a protected sector. See Table 3 for Autoselect

codes.

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