M29F200 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

M29F200

2 Mbit (256Kb x8 or 128Kb x16, Boot Block) Single Supply Flash Memory

STMicroelectronics 

M29F200T, M29F200B

Block Temporary Unprotection. Any previously

protected block can be temporarily unprotected in

order to change stored data. The temporaryunpro-

tection mode is activated by bringing RP to VID.

During the temporary unprotection mode the pre-

viously protected blocks are unprotected. A block

can be selected and data can be modified by

executingthe Erase or Program instruction with the

RP signal held at VID. When RP is returned to VIH,

all the previously protected blocks are again pro-

tected.

Block Unprotection. All protected blocks can be

unprotected on programming equipment to allow

updating of bit contents. All blocks must first be

protected before the unprotection operation. Block

unprotection is activated when A9, G and E are at

VID and A12, A15 at VIH. The Block Unprotection

algorithm is shown in Figure 15. Unprotection is

initiated by the edge of W falling to VIL. Aftera delay

of 10ms, the unprotection operation will end. Un-

protectionverify is achieved by bringing G and E to

VIL while A0 is at VIL, A6 and A1 are at VIH and A9

remains at VID. In these conditions, reading the

output data will yield 00h if the block defined by the

inputs A12-A16 has been succesfully unprotected.

Each block must be separatelyverified by giving its

address in order to ensure that it has been unpro-

tected.

INSTRUCTIONS AND COMMANDS

The Command Interface latches commands writ-

ten to the memory. Instructions are made up from

one or more commands to perform Read Memory

Array, Read Electronic Signature, Read Block Pro-

tection, Program, Block Erase, Chip Erase, Erase

Suspend and Erase Resume. Commands are

made of addressand data sequences. The instruc-

tionsrequire from 1 to 6 cycles,the first or firstthree

of which are always write operationsused to initiate

the instruction. They are followed by either further

write cycles to confirm the first command or exe-

cute the command immediately. Command se-

quencing must be followed exactly. Any invalid

combination of commands will reset the device to

Read Array. The increased number of cycles has

been chosen to assure maximum data security.

Instructions are initialised by two initial Coded cy-

cles which unlock the Command Interface.In addi-

tion, for Erase, instruction confirmation is again

preceded by the two Coded cycles.

Status Register Bits

P/E.C. status is indicated during execution by Data

Polling on DQ7, detection of Toggle on DQ6 and

DQ2, or Error on DQ5 and Erase Timer DQ3 bits.

Any read attempt during Program or Erase com-

mand executionwill automaticallyoutput these five

Status Register bits. The P/E.C. automatically sets

bits DQ2, DQ3, DQ5, DQ6 and DQ7. Other bits

(DQ0, DQ1 and DQ4) are reserved for future use

and should be masked. See Tables 9 and 10.

Data Polling Bit (DQ7). When Programming op-

erations are in progress, this bit outputs the com-

plement of the bit being programmed on DQ7.

During Erase operation, it outputs a ’0’. After com-

pletion of the operation, DQ7 will output the bit last

programmed or a ’1’ after erasing. Data Polling is

valid and only effective during P/E.C. operation,

that is after the fourth W pulse for programming or

after the sixth W pulse for erase. It must be per-

formed at the address being programmed or at an

address within the block being erased. If all the

blocks selected for erasure are protected, DQ7 will

be set to ’0’ for about 100µs, and then return to the

previous addressed memory data value. See Fig-

ure 11 for the Data Polling flowchart and Figure 10

for the Data Polling waveforms. DQ7 will also flag

the Erase Suspend mode by switching from ’0’ to

’1’ at the start of the Erase Suspend. In order to

monitor DQ7 in the Erase Suspend mode an ad-

dress within a block being erased must be pro-

vided. For a Read Operation in Erase Suspend

mode, DQ7 will output ’1’ if the read is attempted

on a blockbeing erasedand the data valueon other

blocks. During Program operation in Erase Sus-

pend Mode, DQ7 will have the same behaviour as

in the normal program execution outside of the

suspend mode.

Table 7. Commands

Hex Code

Command

00h

Invalid/Reserved

10h

Chip Erase Confirm

20h

Reserved

30h

Block Erase Resume/Confirm

80h

Set-up Erase

90h

Read Electronic Signature/

Block Protection Status

A0h

Program

B0h

Erase Suspend

F0h

Read Array/Reset

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