X9400 Datasheet, PDF (8/22 Pages) Xicor Inc. – Quad Digitally Controlled Potentiometers (XDCP)

X9400
Instruction Format
Notes: (1) “A1 ~ A0”: stands for the device addresses sent by the master.
(2) WPx refers to wiper position data in the Counter Register
(3) “I”: stands for the increment operation, SI held HIGH during active SCK phase (high).
(4) “D”: stands for the decrement operation, SI held LOW during active SCK phase (high).
Read Wiper Counter Register (WCR)
CS
Falling
Edge
device type
identifier
0101
device
addresses
0
0
A
1
A
0
instruction
opcode
1001
WCR
addresses
0
0
P
1
P
0
wiper position
(sent by X9400 on SO) _CS
W W W W W W ^Rising
0 0 P P P P P P ^Edge
543210
Write Wiper Counter Register (WCR)
CS
Falling
Edge
device type
identifier
0101
device
addresses
0
0
A
1
A
0
instruction
opcode
1010
WCR
addresses
0
0
P
1
P
0
Data Byte
(sent by Host on SI)
CS
W W W W W W ^Rising
0 0 P P P P P P ^Edge
543210
Read Data Register (DR)
CS
Falling
Edge
device type
identifier
0101
device
addresses
0
0
A
1
A
0
instruction
opcode
1011
DR and WCR
addresses
RRPP
1010
Data Byte
(sent by X9400 on SO) _CS
W W W W W W ^Rising
0 0 P P P P P P ^Edge
543210
Write Data Register (DR)
device type device instruction
CS ^{identifier addresses opcode}
Falling
Edge
0
1
0
1
0
0
A
1
A
0
1
1
0
0
DR and WCR
addresses
RRPP
1010
Data Byte
(sent by host on SI)
CS
W W W W W W ^Rising
0 0 P P P P P P ^Edge
543210
HIGH-VOLTAGE
WRITE CYCLE
Transfer Data Register (DR) to Wiper Counter Register (WCR)
device type device instruction DR and WCR
CS _{identifier addresses opcode}
Falling
addresses ^CS
Rising
Edge
0
1
0
1
0
0
A
1
A
0
1
1
0
1
R
1
R
0
P
1
P
0
Edge
Transfer Wiper Counter Register (WCR) to Data Register (DR)
CS
Falling
Edge
device type
identifier
0101
device
addresses
0
0
A
1
A
0
instruction
opcode
1110
DR and WCR
addresses
RRPP
1010
CS
Rising
Edge
HIGH-VOLTAGE
WRITE CYCLE
REV 1.1.4 10/11/02
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Characteristics subject to change without notice. 8 of 22