EM39LV040-45RFHC 参数 Datasheet PDF下载

EM39LV040

4M (512Kx8) Bits Flash Memory

SPECIFICATION

Hardware Data Protection

Noise/Glitch Protection:

A WE# or CE# pulse of less than 5 ns will not initiate a

write cycle.

The Write operation is inhibited when V

DD

is less than

1.5V.

Forcing OE# Low, CE# High, or WE# High will inhibit the

Write operation. This prevents inadvertent write during

power-up or power-down.

V

DD

Power Up/Down Detection:

Write Inhibit Mode:

Software Data Protection (SDP)

The EM39LV040 provides the JEDEC approved Software Data Protection (SDP) scheme for

Program and Erase operations. Any Program operation requires the inclusion of the

three-byte sequence. The three-byte load sequence is used to initiate the Program operation,

providing optimal protection from inadvertent Write operations, especially during the system

power-up or power-down transition. Any Erase operation requires the inclusion of six-byte

sequence. See Table 3 below for the specific software command codes. During SDP

command sequence, invalid commands will abort the device to Read mode within T

RC

.

Software Command Sequence

Command

Sequence

Byte Program

Sector Erase

Chip Erase

Software ID

Entry

4

Manufacture ID

Manufacture ID

Manufacture ID

Device ID

Software ID Exit

5

1st Bus

Write Cycle

Addr

1

5555H

5555H

5555H

5555H

5555H

5555H

5555H

5555H

XXH

Data

AAH

AAH

AAH

AAH

AAH

AAH

AAH

AAH

F0H

AAH

2nd Bus

Write Cycle

Addr

1

2AAAH

2AAAH

2AAAH

2AAAH

2AAAH

2AAAH

2AAAH

2AAAH

Data

55H

55H

55H

55H

55H

55H

55H

55H

3rd Bus

Write Cycle

Addr

1

5555H

5555H

5555H

5555H

5555H

5555H

5555H

5555H

Data

A0H

80H

80H

90H

90H

90H

90H

90H

4th Bus

Write Cycle

Addr

1

BA

2

5555H

5555H

Data

Data

AAH

AAH

5th Bus

Write Cycle

Addr

1

Data

6th Bus

Write Cycle

Addr

1

SA

X

3

5555H

Data

2AAAH

2AAAH

55H

55H

30H

10H

0000H

0003H

0040H

7FH

7FH

1FH

0001H 29FH

Software ID Exit

5

5555H

2AAAH

55H

5555H

F0H

Notes:

1. Address format A18-A0 (Hex) & Address A16 can be V

IL

or V

IH

, (but no other value) for the Command sequence.

2. BA = Program byte address.

3. SA

X

for Sector-Erase; uses A19-A12 address lines.

4. The device does not remain in Software Product ID mode if powered down (see Figure 9 for more information).

5. Both Software ID Exit operations are equivalent.

Table 3:

Software Command Sequence

This specification is subject to change without further notice. (07.22.2004 V1.0)

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