A29DL324 datasheet(21/46 Pages) AMICC

21 / 46 page

A29DL324 Series

PRELIMINARY

(May, 2002, Version 0.0)

AMIC Technology, Inc.

Command Definitions

Writing Commands

All operations are executed by writing a command.

To write a command, the write cycle of a standard

microprocessor is used.

The operation of the device is controlled by writing a

command to a register. The command register is a function

that latches the address and data necessary for executing an

instruction and does not occupy the memory area.

If an illegal address or data is written or if an address or data

is written in the wrong sequence, the device is reset to the

read mode.

Table 8. shows the commands and command sequences.

Read / Reset Command

This command resets the device to the read mode.

The read mode is maintained until the contents of the

command register are changed.

Once the device is in the read mode, no command is

necessary for reading data. Data read can be performed

using the read cycle of a standard microprocessor.

The read mode is maintained until the contents of the

command register are changed.

Product ID

The manufacturer code and device code can be read without

inputting a high voltage to the address pin.

If a bank address is specified in the third bus cycle and a read

operation is started from address xx00H in the fourth bus

cycle, manufacturer code 10H is output. If address xx02H

(BYTE mode) or xx01H (WORD mode) is read, the device

code is output. If a read operation is executed from an

address in the bank not specified in the third bus cycle, data

of the memory cell is output.

If a read operation is executed starting from address (BA)

02H (WORD mode) or (BA) 04H (BYTE mode), information

indicating which sector group is protected can be obtained. If

the sector group address is scanned with (A6, A1, A0) = (VIL,

VIH, VIL), "1" is output to I/O0 to indicate that the sector group

is protected (for details refer to Sector Group Protection).

The product ID can be read only from the specified bank. To

read the manufacturer code, device code, and information on

protection of sector group from a bank not specified, write the

read / reset command, specify the bank address to be read,

and then write the product ID command again. To end the

product ID mode, writes the read / reset command. To write

the product ID command in the product ID mode, execute the

read / reset command once.

Program Command Sequence

This command is used to program data.

Program is performed in 1 byte or 1 word units. Program can

be performed regardless of the address sequence, even if the

sector limit is exceeded. However, "0" cannot be changed

back into "1" through the program operation. If overwriting "1"

to "0" is attempted, the program operation is interrupted and

"1" is output to I/O5, or successful program is indicated in data

polling, but actually the data is "0" as before.

Following write by command sequence, the pulse required for

program is automatically generated inside the device and

program verification is automatically performed, so that

control from external is not required.

During automatic program, any command other than the

program suspend is ignored. However, automatic program is

interrupted when hardware reset is performed. Since the

programmed data is not guaranteed in this case, reexecute

the program command following completion of reset.

Upon completion of automatic program, the device returns to

the read mode.

The operation status of automatic program can be determined

by using the hardware sequence flags (I/O7, I/O6, RY/

pins).

See sections “I/O7 (Data Polling)”, “I/O6 (Toggle Bit)”, and

“RY/

BY (Ready / Busy )”.

For the timing waveform and flow chart, refer to Timing

Waveform

for

Write

Cycle

(

WE Controlled),

Timing

Waveform for Write Cycle ( CE Controlled) and Figure 3.

START

Write Program

Command

Sequence

Data Poll

from System

Last Address ?

Programming

Completed

Yes

Increment Address

Figure 3. Program Flow Chart

A29DL324 Datasheet(PDF) 21 Page - AMIC Technology

A29DL324 Datasheet(HTML) 21 Page - AMIC Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

Datasheet Download

Link URL