X9251 Datasheet, PDF (13/25 Pages) Xicor Inc. – Quad Digitally-Controlled (XDCP) Potentiometer

X9251
INSTRUCTION FORMAT
Read Wiper Counter Register (WCR)
CS
Falling
Edge
Device Type
Identifier
0101
Device
Addresses
0 0 A1 A0
Instruction
Opcode
1001
WCR
Addresses
00 0 0
Wiper Position
(Sent by X9251 on SO)
CS
W W W W W W W W _Rising
C C C C C C C C _Edge
RRRRRRRR
76543210
Write Wiper Counter Register (WCR)
CS
Falling
Edge
Device Type
Identifier
0101
Device
Addresses
0 0 A1 A0
Instruction
Opcode
1010
WCR
Addresses
00 0 0
Data Byte
(Sent by Host on SI)
CS
W W W W W W W W _Rising
C C C C C C C C _Edge
RRRRRRRR
76543210
Read Data Register (DR)
Device Type Device
Instruction DR and WCR
Data Byte
CS
Falling
Edge
Identifier
0101
Addresses
0 0 A1 A0
Opcode
1011
Addresses
RB RA P1 P0
(Sent by X9271 on SO)
DDDDDDDD
76543210
CS
Rising
Edge
Write Data Register (DR)
Device Type Device Instruction DR and WCR
Data Byte
CS
Falling
Edge
Identifier
0101
Addresses Opcode
Addresses
(Sent by Host on SI)
0
0
A1 A0
1
1
0
0
RB RA
P1
P0
D
7
D
6
D
5
DDDDD
43210
CS
Rising
Edge
Global Transfer Data Register (DR) to Wiper Counter Register (WCR)
CS ^{Device Type}
Device
Instruction
DR
CS
Falling ^Identifier
Addresses
Opcode
Addresses _Rising
Edge _{0 1 0 1 0 0 A1 A0 0 0 0 1 RB RA 0 0} Edge
Notes: (1) “A1 ~ A0”: stands for the device addresses sent by the master.
(2) WPx refers to wiper position data in the Counter Register
(2) “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).
REV 1.3.3 2/10/04
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Characteristics subject to change without notice. 13 of 25