MCP41100 MICROCHIP [Microchip Technology], MCP41100 Datasheet - Page 18

• Manufacturer Part Number: MCP41100
• Manufacturer: MICROCHIP [Microchip Technology]

MCP41XXX/42XXX
FIGURE 5-1:
FIGURE 5-2:
DS11195C-page 18
C1 C0 Command
0
0
1
1
SCK
CS†
SO‡
SI
0
1
0
1
None
Write Data
Shutdown
None
† There must always be multiples of 16 clocks while CS is low or commands will abort.
‡ The serial data out pin (SO) is only available on the MCP42XXX device.
* P1 is a ‘don’t care’ bit for the MCP41XXX.
X
1
Don’t
Care
Timing Diagram for Writing Instructions or Data to a Digital Potentiometer.
Command Byte Format.
Bits
No Command will be executed.
Write the data contained in Data Byte to the
potentiometer(s) determined by the potenti-
ometer selection bits.
Potentiometer(s) determined by potentiome-
ter selection bits will enter Shutdown Mode.
Data bits for this command are ‘don’t cares’.
No Command will be executed.
2
X
COMMAND Byte
Command
C1 C0 X
3
Bits
First 16 bits shifted out will always be zeros
Data is always latched
in on the rising edge
of SCK.
4
Command Summary
5
Don’t
Care
Bits
X
6
X
P1* P0
Channel
7
Select
Bits
COMMAND BYTE
X C1 C0
Command
8
Selection
Bits
D7 D6 D5 D4 D3 D2 D1 D0
9 10
New Register Data
X
Data is always clocked out
of the SO pin after the
falling edge of SCK.
11 12 13 14 15 16
Potentiometer
Data Byte
X
Selection
P1*
Bits
P1* P0
0
0
1
1
P0
0
1
0
1
Dummy Code: Neither Potentiometer
affected.
Command executed on
Potentiometer 0.
Command executed on
Potentiometer 1.
Command executed on both
Potentiometers.
Potentiometer Selections
X
2003 Microchip Technology Inc.
Data Registers are
loaded on rising
edge of CS. Shift
register is loaded
with zeros at this time.
SO pin will always
drive low when CS
goes high.