28F004BX-B Ver la hoja de datos (PDF) - Intel

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28F004BX-B

4-MBIT (256K X 16, 512K X 8) BOOT BLOCK FLASH MEMORY FAMILY

Intel 

28F400BX-T B 28F004BX-T B

4 2 28F004BX Bus Operations

Mode

Read

Output Disable

Standby

Deep Power-Down

Intelligent Identifier (Mfr)

Intelligent Identifier (Device)

Table 3 Bus Operations

Notes RP CE OE WE

12

VIH

VIL

VIL

VIH

VIH

VIL

VIH

VIH

VIH

VIH

X

X

9

VIL

X

X

X

34

VIH

VIL

VIL

VIH

3 4 5 VIH

VIL

VIL

VIH

Write

6 7 8 VIH

VIL

VIH

VIL

A9 A0 VPP DQ0–7

X

X

X

DOUT

X

X

X High Z

X

X

X High Z

X

X

X High Z

VID VIL

X

89H

VID VIH

X

78H

79H

X

X

X

DIN

NOTES

1 Refer to DC Characteristics

2 X can be VIL or VIH for control pins and addresses VPPL or VPPH for VPP

3 See DC Characteristics for VPPL VPPH VHH VID voltages

4 Manufacturer and Device codes may also be accessed via a CUI write sequence A1 – A18 e X

5 Device ID e 78H for 28F004BX-T and 79H for 28F004BX-B

6 Refer to Table 4 for valid DIN during a write operation

7 Command writes for Block erase or byte program are only executed when VPP e VPPH

6 Program or erase the Boot block by holding RP at VHH

9 RP must be at GND g0 2V to meet the 1 2 mA maximum deep power-down current

4 3 Read Operations

4 3 1 2 Input Control

The 4-Mbit boot block flash family has three user

read modes Array Intelligent Identifier and Status

Register Status Register read mode will be dis-

cussed in detail in the ‘‘Write Operations’’ section

During power-up conditions (VCC supply ramping) it

takes a maximum of 600 ns from when VCC is at

4 5V minimum to valid data on the outputs

With WE at logic-high level (VIH) input to the de-

vice is disabled Data Input Output pins (DQ 0 15

or DQ 0 7 ) are controlled by OE

4 3 2 INTELLIGENT IDENTIFIERS

28F400BX PRODUCTS

4 3 1 READ ARRAY

If the memory is not in the Read Array mode it is

necessary to write the appropriate read mode com-

mand to the CUI The 4-Mbit boot block flash family

has three control functions all of which must be

logically active to obtain data at the outputs

Chip-Enable CE is the device selection control

Power-Down RP is the device power control Out-

put-Enable OE is the DATA INPUT OUTPUT

(DQ 0 15 or DQ 0 7 ) direction control and when

active is used to drive data from the selected memo-

ry on to the I O bus

4 3 1 1 Output Control

With OE at logic-high level (VIH) the output from

the device is disabled and data input output pins

(DQ 0 15 or DQ 0 7 are tri-stated Data input is

then controlled by WE

The manufacturer and device codes are read via the

CUI or by taking the A9 pin to 12V Writing 90H to

the CUI places the device into Intelligent Identifier

read mode A read of location 00000H outputs the

manufacturer’s identification code 0089H and loca-

tion 00001H outputs the device code 4470H for

28F400BX-T 4471H for 28F400BX-B When

BYTE is at a logic low only the lower byte of the

above signatures is read and DQ15 Ab1 is a ‘‘don’t

care’’ during Intelligent Identifier mode A read array

command must be written to the memory to return to

the read array mode

28F004BX PRODUCTS

The manufacturer and device codes are also read

via the CUI or by taking the A9 pin to 12V Writing

90H to the CUI places the device into Intelligent

Identifier read mode A read of location 00000H out-

puts the manufacturer’s identification code 89H

and location 00001H outputs the device code 78H

for 28F004BX-T 79H for 28F004BX-B

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