Write (WRITE)

The WRITE instruction is followed by 16 bits of data to be

written into the specificed address After the last bit of data

is put on the data-in (DI) pin CS must be brought low before

the next rising edge of the SK clock This falling edge of CS

initiates the self-timed programming cycle The DO pin indi-

cates the READYBUSY status of the chip if CS is brought

that the register at the address specified in the instruction

has been written with the data pattern specified in the in-

struction and the part is ready for another instruction

Erase All (ERAL)

The ERAL instruction will simultaneously program all regis-

ters in the memory array and set each bit to the logical ‘‘1’’

state The Erase All cycle is identical to the ERASE cycle

except for the different op-code As in the ERASE mode

the DO pin indicates the READYBUSY status of the chip if

Write All (WRALL)

The WRALL instruction will simultaneously program all reg-

isters with the data pattern specified in the instruction As in

the WRITE mode the DO pin indicates the READYBUSY

Write Disable (WDS)

To protect against accidental data distrub the WDS instruc-

tion disables all programming modes and should follow all

programming operations Execution of a READ instruction is

independent of both the WEN and WDS instructions

Note

NSC CMOS EEPROMs do not require an ‘‘ERASE’’ or ‘‘ERASE ALL’’ operation prior to the ‘‘WRITE’’ and ‘‘WRITE ALL’’ instructions The ‘‘ERASE’’ and

‘‘ERASE ALL’’ instructions are included to maintain compatibility with earlier technology EEPROMs

Instruction Set for the NM93C06L and NM93C46L

Instruction

SB

Op Code

Address

Data

Comments

READ

1

10

A5 – A0

Reads data stored in memory at specified address

WEN

1

00

11XXXX

Enable all programming modes

ERASE

1

11

A5 – A0

Erase selected register

WRITE

1

01

A5 – A0

D15 – D0

Writes selected register

ERAL

1

00

10XXXX

Erases all registers

WRALL

1

00

01XXXX

D15 – D0

Writes all registers

WDS

1

00

00XXXX

Disables all programming modes

Note

Address bits A5 and A4 become ‘‘Don’t Care’’ for the NM93C06L

Instruction Set for the NM93C56L and NM93C66L

Instruction

SB

Op Code

Address

Data

Comments

READ

1

10

A7 – A0

Reads data stored in memory at specified address

WEN

1

00

11XXXXXX

Enable all programming modes

ERASE

1

11

A7 – A0

Erase selected register

WRITE

1

01

A7 – A0

D15 – D0

Writes selected register

ERAL

1

00

10XXXXXX

Erases all registers

WRALL

1

00

01XXXXXX

D15 – D0

Writes all registers

WDS

1

00

00XXXXXX

Disables all programming modes

Note

Address bit A7 is ‘‘Don’t Care’’ for the NM93C56L

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