M36W108B データシートの表示（PDF） - STMicroelectronics

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M36W108B

8 Mbit (1Mb x8, Boot Block) Flash Memory and 1 Mbit (128Kb x8) SRAM Low Voltage Multi-Memory Product

STMicroelectronics 

M36W108T, M36W108B

Block Erase (BE) Instruction. This instruction

uses a minimum of six write cycles. The Erase

Set-up command 80h is written to address 5555h

on third cycle after the two Coded cycles. The

Block Erase Confirm command 30h is similarly

written on the sixth cycle after another two Coded

Cycles. During the input of the second command

an address within the block to be erased is given

and latched into the memory.

Additional block Erase Confirm commands and

block addresses can be written subsequently to

erase other blocks in parallel, without further Cod-

ed cycles. The erase will start after the erase tim-

eout period (see Erase Timer Bit DQ3 description).

Thus, additional Erase Confirm commands for oth-

er blocks must be given within this delay. The input

of a new Erase Confirm command will restart the

timeout period. The status of the internal timer can

be monitored through the level of DQ3, if DQ3 is ’0’

the Block Erase Command has been given and

the timeout is running, if DQ3 is ’1’, the timeout has

expired and the P/E.C. is erasing the block(s). If

the second command given is not an erase con-

firm or if the Coded cycles are wrong, the instruc-

tion aborts, and the device is reset to Read Array.

It is not necessary to program the block with 00h

as the P/E.C. will do this automatically before to

erasing to FFh. Read operations after the sixth ris-

ing edge of W or EF output the Status Register

bits.

During the execution of the erase by the P/E.C.,

the memory only accepts the Erase Suspend (ES)

and Read/Reset (RD) instructions. A Read/Reset

command will definitively abort erasure and result

in invalid data in blocks being erased. A complete

state of the block erase operation is given by the

Status Register bits (see DQ2, DQ3, DQ5, DQ6

and DQ7 description).

Chip Erase (CE) Instruction. This instruction

uses six write cycles. The Erase Set-up command

80h is written to address 5555h on the third cycle

after the two Coded Cycles. The Chip Erase Con-

firm command 10h is similarly written on the sixth

cycle after another two Coded Cycles. If the sec-

ond command given is not an erase confirm or if

the Coded Sequence is wrong, the instruction

aborts and the device is reset to Read Array. It is

not necessary to program the array with 00h first

as the P/E.C. will automatically do this before

erasing it to FFh. Read operations after the sixth

rising edge of W or EF output the Status Register

bits. A complete state of the chip erase operation

is given by the Status Register bits (see DQ2,

DQ3, DQ5, DQ6 and DQ7 description).

Erase Suspend (ES) Instruction. The Block

Erase operation may be suspended by this in-

struction which consists of writing the command

B0h without any specific address. No Coded Cy-

cles are required. It permits reading of data from

another block and programming in another block

while an erase operation is in progress. Erase sus-

pend is accepted only during the Block Erase in-

struction execution. Writing this command during

the erase timeout period will, in addition to sus-

pending the erase, terminate the timeout. The

Toggle bit DQ6 stops toggling when the P/E.C. is

suspended. The Toggle bits will stop toggling be-

tween 0.1µs and 15µs after the Erase Suspend

(ES) command has been written. The device will

then automatically be set to Read Memory Array

mode. When erase is suspended, a Read from

blocks being erased will output DQ2 toggling and

DQ6 at '1'. A Read from a block not being erased

returns valid data. During suspension the memory

will respond only to the Erase Resume (ER) and

the Program (PG) instructions. A Program opera-

tion can be initiated during Erase Suspend in one

of the blocks not being erased. It will result in both

DQ2 and DQ6 toggling when the data is being pro-

grammed. A Read/Reset command will definitively

abort erasure and result in invalid data in the

blocks being erased.

Erase Resume (ER) Instruction. If an Erase

Suspend instruction was previously executed, the

erase operation may be resumed by giving the

command 30h, at any address, and without any

Coded cycles.

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