This Data Sheet may be revised by subsequent versions

©2003 Eon Silicon Solution, Inc., www.essi.com.tw

or modifications due to changes in technical specifications.

8

EN29F040A

Rev. B, Issue Date: 2004/04/01

Table 5. EN29F040A Command Definitions

1

st

Write Cycle

2

nd

Write Cycle

3

rd

Write Cycle

4

th

Write Cycle

5

th

Write Cycle

6

th

Write Cycle

Command

Sequence

Read/Reset

Write

Cycles

Req’d

Addr

Data

Addr

Data

Addr

Data

Addr

Data

Addr

Data

Addr

Data

Read

1

RA

RD

Reset

1

XXXh

F0h

Read/Reset

4

555h

AAh

2AAh

55h

555h

F0h

RA

RD

AutoSelect

Manufacturer ID

4

555h

AAh

2AAh

55h

555h

90h

000h/

100h

7Fh/

1Ch

AutoSelect Device ID

4

555h

AAh

2AAh

55h

555h

90h

001h/

101h

7Fh/

04h

AutoSelect Sector

Protect Verify

4

555h

AAh

2AAh

55h

555h

90h

BA &

02h

00h/

01h

Byte Program

4

555h

AAh

2AAh

55h

555h

A0h

PA

PD

Chip Erase

6

555h

AAh

2AAh

55h

555h

80h

555h

AAh 2AAh

55h

555h

10h

Sector Erase

6

555h

AAh

2AAh

55h

555h

80h

555h

AAh 2AAh

55h

SA

30h

Sector Erase Suspend

1

xxxh

B0h

Sector Erase Resume

1

xxxh

30h

Notes:

PA = Program Address: address of the memory location to be programmed

PD = Program Data: data to be programmed at location PA

SA = Sector Address: address of the Sector to be erased. Address bits A18-A16 uniquely select any Sector.

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

Byte Programming Command

Programming the EN29F040A is performed on a byte-by-byte basis using a four bus-cycle operation

(two unlock write cycles followed by the Program Setup command and Program Data Write cycle).

When the program command is executed, no additional CPU controls or timings are necessary. An

internal timer terminates the program operation automatically. Address is latched on the falling edge

The program operation is completed when EN29F040A returns the equivalent data to the

programmed location.

bit).

Changing data from 0 to 1 requires an erase operation.

When programming time limit is

exceeded, DQ5 will produce a logical “1” and a Reset command can return the device to Read

mode.

Chip Erase Command

Chip erase is a six-bus-cycle operation. The chip erase command sequence is initiated by writing two

unlock cycles, followed by a set-up command. Two additional unlock write cycles are then followed by the

chip erase command, which in turn invokes the Embedded Erase algorithm. The device does

the system to preprogram prior to erase. The Embedded Erase algorithm automatically preprograms and

verifies the entire memory for an all zero data pattern prior to electrical erase. The system is not required

to provide any controls or timings during these operations. The Command Definitions table shows the

address and data requirements for the chip erase command sequence.