X9420

Characteristics subject to change without notice.

8 of 20

REV 1.1.6 7/30/02

www.xicor.com

Instruction Format

Notes: (1) “A1 ~ A0”: stands for the device addresses sent by the master.

(2) WPx refers to wiper position data in the Wiper Counter Register

“I”: stands for the increment operation, SI held HIGH during active SCK phase (high).

(3) “D”: stands for the decrement operation, SI held LOW during active SCK phase (high).

Read Wiper Counter Register (WCR)

Write Wiper Counter Register (WCR)

Read Data Register (DR)

Read the contents of the Register pointed to by R1-R0.

Write Data Register (DR)

Write a new value to the Register pointed to by R1-R0.

Transfer Data Register (DR) to Wiper Counter Register (WCR)

Transfer the contents of the Register pointed to by R1-R0 to the WCR.

CS

Falling

Edge

device type

identifier

device

addresses

instruction

opcode

wiper position

(sent by X9420 on SO)

CS

Rising

Edge

0101110

A

0

1001000000

W

P

5

W

P

4

W

P

3

W

P

2

W

P

1

W

P

0

CS

Falling

Edge

device type

identifier

device

addresses

instruction

opcode

Data Byte

(sent by Host on SI)

CS

Rising

Edge

0101110

A

0

1010000000

W

P

5

W

P

4

W

P

3

W

P

2

W

P

1

W

P

0

CS

Falling

Edge

device type

identifier

device

addresses

instruction

opcode

register

addresses

Data Byte

(sent by X9420 on SO)

CS

Rising

Edge

0101110

A

0

1011

R

1

R

0

0000

W

P

5

W

P

4

W

P

3

W

P

2

W

P

1

W

P

0

CS

Falling

Edge

device type

identifier

device

addresses

instruction

opcode

register

addresses

Data Byte

(sent by host on SI)

CS

Rising

Edge

HIGH-VOLTAGE

WRITE CYCLE

0101110

A

0

1100

R

1

R

0

0000

W

P

5

W

P

4

W

P

3

W

P

2

W

P

1

W

P

0

CS

Falling

Edge

device type

identifier

device

addresses

instruction

opcode

register

addresses

CS

Rising

Edge

0101110

A

0

1101

R

1

R

0

00