7

HY29F040A

COMMAND DEFINITIONS

Device operations are selected by writing

specific address and data sequences into the

Command register. Writing incorrect addresses

and data values or writing them in the improper

Bus

First Bus

Second Bus

Third Bus

Fourth Bus

Fifth Bus

Sixth Bus

Command

Write

Write Cycle

Write Cycle

Write Cycle

Write Cycle

Write Cycle

Write Cycle

Sequence

Cycles

Req'd

Addr

Data

Addr

Data

Addr

Data

Addr

Data

Addr

Data

Addr

Data

Read/Reset

1

XXXH

F0H

RA

RD

Read/Reset

4

5555H

AAH

2AAAH

55H

5555H

F0H

RA

RD

Electronic ID

4

5555H

AAH

2AAAH

55H

5555H

90H

XX00H

ADH

XX01H

A4H

Byte Program

4

5555H

AAH

2AAAH

55H

5555H

A0H

PA

PD

Chip Erase

6

5555H

AAH

2AAAH

55H

5555H

80H

5555H

AAH

2AAAH

55H

5555H

10H

Sector Erase

6

5555H

AAH

2AAAH

55H

5555H

80H

5555H

AAH

2AAAH

55H

SA

30H

Erase Suspend

1

XXXH

B0H

Erase Resume

1

XXXH

30H

Notes:

1.

Bus Operations are defined in Table 1.

2.

For a Command Sequence, address bits A15, A14, A13, A12, and A11 = X = Don’t care. Address bits A18, A17, A16,

and A15 = X = Don’t care for all address commands except for Program Address(PA) and Sector Address(SA).

In the case of Sector Address, address bit A15 = X = Don’t care for all addresses except for Program Address (PA)

and Sector Addresses (SA).

3.

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 are latched on the falling edge of the /WE pulse.

PD = Data to be programmed at location PA. Data is latched on the falling edge of /WE.

SA = Address of the sector to be erased (see Table 3).

4.

The Erase Suspend (B0H) and Erase Resume (30H) commands are valid only while the Sector Erase opera

tion

is in progress.

sequence will reset the device to Read mode.

Table 4 defines the valid register command

sequences. Either Read/Reset command will

reset the device (when applicable).