MX29F400BMC-12 Просмотр технического описания (PDF) - Macronix International

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MX29F400BMC-12

4M-BIT [512Kx8/256Kx16] CMOS FLASH MEMORY

Macronix International 

MX29F400T/B

READ/RESET COMMAND

The read or reset operation is initiated by writing the

read/reset command sequence into the command reg-

ister. Microprocessor read cycles retrieve array data.

The device remains enabled for reads until the command

register contents are altered.

If program-fail or erase-fail happen, the write of F0H will

reset the device to abort the operation. A valid com-

mand must then be written to place the device in the

desired state.

SILICON-ID-READ COMMAND

Flash memories are intended for use in applications where

the local CPU alters memory contents. As such, manu-

facturer and device codes must be accessible while the

device resides in the target system. PROM program-

mers typically access signature codes by raising A9 to

a high voltage. However, multiplexing high voltage onto

address lines is not generally desired system design

practice.

The MX29F400T/B contains a Silicon-ID-Read opera-

tion to supplement traditional PROM programming meth-

odology. The operation is initiated by writing the read

silicon ID command sequence into the command regis-

ter. Following the command write, a read cycle with

A1=VIL,A0=VIL retrieves the manufacturer code of C2H/

00C2H. A read cycle with A1=VIL, A0=VIH returns the

device code of 23H/2223H for MX29F400T, ABH/22ABH

for MX29F400B.

SET-UP AUTOMATIC CHIP/SECTOR ERASE

COMMANDS

Chip erase is a six-bus cycle operation. There are two

"unlock" write cycles. These are followed by writing the

"set-up" command 80H. Two more "unlock" write cy-

cles are then followed by the chip erase command 10H.

The Automatic Chip Erase does not require the device

to be entirely pre-programmed prior to executing the Au-

tomatic Chip Erase. Upon executing the Automatic Chip

Erase, the device will automatically program and verify

the entire memory for an all-zero data pattern. When the

device is automatically verified to contain an all-zero

pattern, a self-timed chip erase and verify begin. The

erase and verify operations are completed when the data

on Q7 is "1" at which time the device returns to the

Read mode. The system is not required to provide any

control or timing during these operations.

When using the Automatic Chip Erase algorithm, note

that the erase automatically terminates when adequate

erase margin has been achieved for the memory array(no

erase verification command is required).

If the Erase operation was unsuccessful, the data on

Q5 is "1"(see Table 4), indicating the erase operation

exceed internal timing limit.

The automatic erase begins on the rising edge of the

last WE or CE, whichever happens later, pulse in the

command sequence and terminates when the data on

Q7 is "1" and the data on Q6 stops toggling for two con-

secutive read cycles, at which time the device returns

to the Read mode.

TABLE 3. EXPANDED SILICON ID CODE

Pins

Manufacture code

Device code

for MX29F400T

Device code

for MX29F400B

Sector Protection

Verification

A0

Word VIL

Byte VIL

Word VIH

Byte VIH

Word VIH

Byte VIH

X

X

A1 Q15~Q8 Q7 Q6 Q5

VIL 00H

110

VIL X

110

VIL 22H

001

VIL X

001

VIL 22H

101

VIL X

101

VIH X

000

VIH X

000

Q4 Q3 Q2 Q1 Q0 Code(Hex)

0 0 0 1 0 00C2H

0 0 0 1 0 C2H

0 0 0 1 1 2223H

0 0 0 1 1 23H

0 1 0 1 1 22ABH

0 1 0 1 1 ABH

0 0 0 0 1 01H (Protected)

0 0 0 0 0 00H (Unprotected)

P/N:PM0439

REV. 1.6, NOV. 12, 2001

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