MCP4431 Microchip Technology Inc., MCP4431 Datasheet - Page 63

• Manufacturer Part Number: MCP4431
• Description: 7/8-bit Volatile Quad Digital Pot With I 2c Interface
• Manufacturer: Microchip Technology Inc.

7.6
The Increment Command provides a quick and easy
method to modify the potentiometer’s wiper by +1 with
minimal overhead. The Increment Command will only
function on the volatile wiper setting memory locations
00h, 01h, 06h and 07h.
When executing an Increment Command, the volatile
wiper setting will be altered from n to n+1 for each
Increment
increment up to 100h max on 8-bit devices and 80h on
7-bit devices. If multiple Increment Commands are
received after the value has reached 100h (or 80h), the
value will not be incremented further.
the Increment Command versus the current volatile
wiper value.
The Increment Command will most commonly be
performed on the Volatile Wiper locations until a
desired condition is met. The MCP44XX is responsible
for generating the A bits.
Refer to
sequence. The sequence is terminated by the Stop
condition. So when executing a continuous command
string, the Increment command can be followed by any
other valid command. This means that writes do not
need to be to the same volatile memory address.
The advantage of using an Increment Command
instead of a read-modify-write series of commands is
speed and simplicity. The wiper will transition after each
Command Acknowledge when accessing the volatile
wiper registers.
FIGURE 7-7:
 2010 Microchip Technology Inc.
Note:
Note:
S
Increment Wiper
Normal and High Voltage
Note1: Increment Command (INCR) only functions when accessing the volatile wiper
0 1 0
Figure 7-7
Fixed
Address
Table 7-4
the Increment Wiper command. Other
addresses are invalid.
The command sequence can go from an
increment to any other valid command for
the specified address.
Command
2: This command sequence does not need to terminate (using the Stop bit) and can
Control Byte
registers (AD3:AD0 = 00h, 01h, 06h, and 07h).
change to any other desired command sequence (Increment, Read, or Write).
1
shows the valid addresses for
I
for the Increment Command
2
1 A1 A0 0
C Increment Command Sequence.
received.
Variable
Address
Write bit
The
Table 7-4
A
AD AD AD AD
3
value
Device
Memory
Address
2
INCR Command (n+1)
shows
1
will
0
Command
0
1 x
TABLE 7-4:
7.6.1
The High Voltage Command (HVC) signal is
multiplexed with Address 0 (A0) and is used to indicate
that the command, or sequence of commands, are in
the High Voltage mode. Signals > V
HVC/A0 pin puts MCP44XX devices into High Voltage
mode.
The HVC pin has an internal resistor connection to the
MCP44XX’s internal V
Current Wiper
3FFh
07Fh
03Fh
081h
080h
041h
040h
001h
000h
Note:
7-bit
Pot
X A
Setting
AD AD AD AD
3FFh
0FFh
101h
100h
080h
07Fh
000h
8-bit
4
THE HIGH VOLTAGE COMMAND
(HVC) SIGNAL
There is a required delay after the HVC pin
is driven to the V
of the SCL pin.
081
001
Pot
3 2
INCR Command (n+2)
INCREMENT OPERATION VS.
VOLATILE WIPER VALUE
Reserved
(Full-Scale (W = A))
Full-Scale (W = A)
W = N
W = N (Mid-Scale)
W = N
Zero Scale (W = B) Yes
MCP443X/5X
DD
1
Properties
Wiper (W)
signal.
0
IHH
1 x
level to the 1st edge
IHH
DS22267A-page 63
X A P
(~8.5V) on the
No
No
Yes
Command
Operates?
Increment
(2)