Instruction Set for the NM93CS06 and NM93CS46

Instruction

SB

Op Code

Address

Data

PRE

PE

Comments

READ

1

10

A5 – A0

0

X

Reads data stored in memory starting at specified address

WEN

1

00

11XXXX

0

1

Enable all programming modes

WRITE

1

01

A5 – A0

D15 – D0

0

1

Writes address if unprotected

WRALL

1

00

01XXXX

D15 – D0

0

1

Writes all registers Valid only when Protect Register is

cleared

WDS

1

00

00XXXX

0

X

Disables all programming modes

PRREAD

1

10

XXXXXX

1

X

Reads address stored in Protect Register

PREN

1

00

11XXXX

1

1

Must immediately precede PRCLEAR PRWRITE and

PRDS instructions

PRCLEAR

1

11

111111

1

1

Clears the Protect Register so that no registers are

protected from WRITE

PRWRITE

1

01

A5 – A0

1

1

Programs address into Protect Register Thereafter

protected from WRITE

PRDS

1

00

000000

1

1

ONE TIME ONLY instruction after which the address in the

Protect Register cannot be altered

Note

Address bits A5 and A4 become ‘‘Don’t Care’’ for the NM93CS06

Instruction Set for the NM93CS56 and NM93CS66

Instruction

SB

Op Code

Address

Data

PRE

PE

Comments

READ

1

10

A7 – A0

0

X

Reads data stored in memory starting at specified address

WEN

1

00

11XXXXXX

0

1

Enable all programming modes

WRITE

1

01

A7 – A0

D15 – D0

0

1

Writes address if unprotected

WRALL

1

00

01XXXXXX

D15 – D0

0

1

Writes all registers Valid only when Protect Register is

cleared

WDS

1

00

00XXXXXX

0

X

Disables all programming modes

PRREAD

1

10

XXXXXXXX

1

X

Reads address stored in Protect Register

PREN

1

00

11XXXXXX

1

1

Must immediately precede PRCLEAR PRWRITE and

PRDS instructions

PRCLEAR

1

11

11111111

1

1

Clears the ‘‘protect register’’ so that no registers are

protected from WRITE

PRWRITE

1

01

A7 – A0

1

1

Programs address into Protect Register Thereafter

protected from WRITE

PRDS

1

00

00000000

1

1

ONE TIME ONLY instruction after which the address in the

Protect Register cannot be altered

Note

Address bit A7 becomes ‘‘Don’t Care’’ for the NM93CS56

6