FLASH

AS8FLC2M32

AS8FLC2M32B

Rev. 1.6 05/11

Micross Components reserves the right to change products or specifications without notice.

3

A system reset would then also reset the FLASH device,

enabling the system microprocessor to read the boot-up

firmware from the FLASH memory array. The device offers two

power-saving features. When addresses have been stable for a

specified amount of time, the device enters the AUTOMATIC

SLEEP MODE. The system can also place the device into the

STANDBY mode. Power consumption is greatly reduced in

both these modes.

Device Bus Operations

This section describes the use of the command register for setting

and controlling the bus operations. The command register itself

does not occupy any addressable memory locations. The register

is composed of a series of latches that store the commands,

addresses and data information needed to execute the indicated

command. The contents of the register serve as the input to the

internal state machine. The state machine output dictates the

function of the device. Table 1 lists the device bus operations,

the inputs and control/stimulus levels they require, and the

resulting output. The following subsections describe each of

these operations in further detail.

Requirements for Reading Array Data

To read array data from the outputs, the system must drive the

CSx\ and OE\ pins to VIL. Chip Select CSx\ is the power and

chip select control of the byte or bytes targeted by the system

(user). Output Enable [OE\] is the output control and gates array

data to the output pins. Write (byte) Enables [WEx\] should

remain at VIH levels.

The internal state machine is set for reading array data upon

device power-up, or after a HARDWARE RESET. This ensures

that no spurious alteration of the memory content occurs

during

Table 1

the power transition. No command is necessary in this mode to

obtain array data. Standard microprocessor read cycles that

assert valid data on the device address inputs produce valid

data on the data outputs. The device remains enabled for read

access until the command register contents are altered.

See READING ARRAY DATA for more information. Refer

to AC Read Operations table data for timing specifications

relevant to this operational mode.

Writing Commands/Command Sequences

To WRITE a command or command sequence, the system must

drive CSx\, WEx\ to VIL and OE\ to VIH.

An ERASE command operation can erase one sector, multiple

sectors, or the entire array. Table 2 indicates the address

space contained within each sector within the array. A sector

address

consists of the address bits required to uniquely select a

sector.

The “Command Definitions” section has details on erasure

of a single, multiple sectors, the entire array or suspending/

resuming the erase operation.

After the system writes the autoselect command sequence, the

device enters the autoselect mode. The system can then read

autoselect codes from the internal register (which is separate

from the memory array) on each of the Data input/output bits

within each byte of the MCM FLASH array. Standard read

cycle timings apply in this mode. Refer to the Autoselect

Mode and Autoselect Command Sequence sections for more

information.

ICC2 in the DC Characteristics table represents that active

current specification for the WRITE mode. The AC

Characteristics section contains timing specifications for Write

Operations.

RESET\

CS1\

CS2\

CS3\

CS4\

WE1\ WE2\ WE3\ WE4\ OE\

OPERATION

ADDRESSES

DATA BUS (DQ0-DQX)

L

HHH

D0-D7 Out

HL

H

H

D8-D15 Out

HH

L

H

D16-D31 Out

HHH

L

D24-D31 Out

LLLL

D0-D31 Out

L

HHH

L

H

H

H

D0-D7 In

H

L

H

H

H

L

H

H

D8-D15 In

H

H

L

H

H

H

L

H

D16-D31 In

H

H

H

L

H

H

H

L

D24-D31 In

LLLL

LLLL

D0-D31 In

VCC +/- 0.3V

VCC +/- 0.3V

VCC +/- 0.3V

VCC +/- 0.3V

VCC +/- 0.3V

XXXX

X

Standby

X

X

L

L

L

L

HHHH

H

Output Diable

X

L

XXXX

XXXX

X

Reset

X

VID

L

L

L

L

LLLL

H

Sector Protect

SECTOR ADDRESS

A7=L, A2=H, A1=L

VID

LLLL

LLLL

H

Sector Unprotect

SECTOR ADDRESS

A7=L, A2=H, A1=L

VID

XXXX

XXXX

X

Temporary Sector Unprotect

Legend

Notes

H

WRITE

A0-Ax In

H

H

L

READ

A0-Ax In

H

HHH