CAT5401WI-10 ONSEMI [ON Semiconductor], CAT5401WI-10 Datasheet - Page 9

• Manufacturer Part Number: CAT5401WI-10
• Description: Quad Digitally Programmable Potentiometers with 64 Taps and SPI Interface
• Manufacturer: ONSEMI [ON Semiconductor]

The basic sequence of the three byte instructions is
illustrated in Figure 4. These three-byte instructions
exchange data between the WCR and one of the Data
Registers. The WCR controls the position of the wiper.
The response of the wiper to this action will be
delayed by t
wiper position), to a Data Register is a write to non-
volatile memory and takes a minimum of t
complete. The transfer can occur between one of the
four potentiometers and one of its associated
registers; or the transfer can occur between all
potentiometers and one associated register.
Four instructions require a two-byte sequence to
complete, as illustrated in Figure 3. These instructions
transfer data between the host/processor and the
CAT5401; either between the host and one of the data
registers or directly between the host and the Wiper
Control Register. These instructions are:
— XFR Data Register to Wiper Control Register
— XFR Wiper Control Register to Data Register
Figure 3. Two-Byte Instruction Sequence
Figure 4. Three-Byte Instruction Sequence
Figure 5. Increment/Decrement Instruction Sequence
© 2008 SCILLC. All rights reserved.
Characteristics subject to change without notice
This transfers the contents of one specified Data
Register to the associated Wiper Control Register.
This transfers the contents of the specified Wiper
Control Register to the specified associated Data
Register.
SI
SI
WRL
ID3 ID2 ID1 ID0
ID3 ID2 ID1 ID0
0
0
. A transfer from the WCR (current
Device ID
Device ID
1
1
SI
0
0
1
1
A3
ID3 ID2 ID1 ID0
0
A3
0
0
A2
Device ID
0
Internal
Address
Internal
Address
1
A2 A1 A0
0
A1
0
A0
1
I3
A3
0
I3
Instruction
Opcode
A2
I2
0
Internal
Address
WR
Instruction
Opcode
A1
I2
I1 I0
to
A0
I1
9
I3
R1 R0
Data
Register
Address
I0
— Gang XFR Data Register to Wiper Control
— Gang XFR Wiper Counter Register to Data
Increment/Decrement Command
The final command is Increment/Decrement (Figure
5). The Increment/Decrement command is different
from the other commands. Once the command is
issued the master can clock the selected wiper up
and/or down in one segment steps; thereby providing
a fine tuning capability to the host. For each SCK
clock pulse (t
will move one resistor segment towards the R
terminal. Similarly, for each SCK clock pulse while SI
is LOW, the selected wiper will move one resistor
segment towards the R
See Instructions format for more detail.
Instruction
Opcode
I2
R1
Data
Register
Address
Register
This transfers the contents of all specified Data
Registers to the associated Wiper Control
Registers.
Register
This transfers the contents of all Wiper Control
Registers to the specified associated Data
Registers.
I1
Address
P1 P0
Pot/WCR
R0 P1 P0
I0
Pot/WCR
Address
Register
Address
R1 R0 P1
D7 D6 D5 D4 D3 D2 D1 D0
HIGH
) while SI is HIGH, the selected wiper
N
C
1
I
Data Register D[7:0]
Pot/WCR
N
C
Address
2
I
WCR[7:0]
P0
L
terminal.
or
N
C
n
I
D
E
C
1
Doc. No. MD-2012 Rev. I
D
E
C
n
CAT5401
H