18

Am29DL400B

COMMAND DEFINITIONS

Table 5. Am29DL400B Command Definitions

Legend:

X = Don’t care

RA = Address of the memory location to be read.

RD = Data read from location RA during read operation.

PA = Address of the memory location to be programmed. Addresses latch on the falling edge of the WE# or CE# pulse,

whichever happens later.

PD = Data to be programmed at location PA. Data latches on the rising edge of WE# or CE# pulse, whichever happens first.

SA = Address of the sector to be verified (in autoselect mode) or erased. Address bits A17–A12 uniquely select any sector.

BA = Address of the bank that is being switched to autoselect mode, is in bypass mode, or is being erased. Address bits A17–

A16 select a bank.

Notes:

1. See Table 1 for description of bus operations.

2. All values are in hexadecimal.

3. Except when reading array or autoselect data, all bus

cycles are write operations.

4. Data bits DQ15–DQ8 are don’t cares for unlock and

command cycles in word mode.

5. Address bits A17–A11 are don’t cares for unlock and

command cycles, unless bank address (BA) is required.

6. No unlock or command cycles required when bank is in

read mode.

7. The Reset command is required to return to reading

array data (or to the erase-suspend-read mode if

previously in Erase Suspend) when a bank is in the

autoselect mode, or if DQ5 is goes high (while the bank

is providing status information).

8. The fourth cycle of the autoselect command sequence is

a read cycle. The system must provide the bank address

to obtain the manufacturer or device ID information.

9. The data is 00h for an unprotected sector and 01h for a

protected sector. See the

Autoselect Command

10. The Unlock Bypass command is required prior to the

Unlock Bypass Program command.

11. The Unlock Bypass Reset command is required to return

to reading array data when the bank is in the unlock

bypass mode.

12. The system may read and program in non-erasing

sectors, or enter the autoselect mode, when in the Erase

Suspend mode. The Erase Suspend command is valid

only during a sector erase operation, and requires the

bank address.

13. The Erase Resume command is valid only during the Erase

Suspend mode, and requires the bank address.

Command

Sequence

(Note 1)

Bus Cycles (Notes 2–5)

First

Second

Third

Fourth

Fifth

Sixth

Addr Data Addr Data

Addr

Data

Addr

Data

Addr Data Addr Data

Read (Note 6)

1

RA

RD

Reset (Note 7)

1

XXX

F0

Manufacturer ID

Word

4

555

AA

2AA

55

(BA)555

90

(BA)X00

01

Byte

AAA

555

(BA)AAA

Device ID,

Top Boot Block

Word

4

555

AA

2AA

55

(BA)555

90

(BA)X01

220C

Byte

AAA

555

(BA)AAA

(BA)X02

0C

Device ID,

Bottom Boot Block

Word

4

555

AA

2AA

55

(BA)555

90

(BA)X01

220F

Byte

AAA

555

(BA)AAA

(BA)X02

0F

Sector Protect Verify

(Note 9)

Word

4

555

AA

2AA

55

(BA)555

90

(SA)

X02

XX00

XX01

Byte

AAA

555

(BA)AAA

(SA)

X04

00

01

Program

Word

4

555

AA

2AA

55

555

A0

PA

PD

Byte

AAA

555

AAA

Unlock Bypass

Word

3

555

AA

2AA

55

555

20

Byte

AAA

555

AAA

Unlock Bypass Program (Note 10)

2

XXX

A0

PA

PD

Unlock Bypass Reset (Note 11)

2

BA

90

XXX

00

Chip Erase

Word

6

555

AA

2AA

55

555

80

555

AA

2AA

55

555

10

Byte

AAA

555

AAA

AAA

555

AAA

Sector Erase

Word

6

555

AA

2AA

55

555

80

555

AA

2AA

55

SA

30

Byte

AAA

555

AAA

AAA

555

Erase Suspend (Note 12)

1

BA

B0

Erase Resume (Note 13)

1

BA

30