Datasheet

MCP4011/2/3/4
DS21978C-page 36 © 2006 Microchip Technology Inc.
5.2.7 HIGH-VOLTAGE DECREMENT 1
(FOR MCP402X COMPATIBILITY)
This mode is achieved by initializing the U/D
pin to a
low state (V
IL
) prior to the CS pin being driven to V
IHH
.
Subsequent rising edges of the U/D pin decrement the
wiper setting toward terminal B. Set the U/D
pin to the
low state (V
IL
) prior to forcing the CS pin to V
IH
. This is
shown in Figure 5-7.
After the CS
pin is driven to V
IH
(from V
IL
), any other
serial command may immediately be entered.
FIGURE 5-7: High-Voltage Decrement 1 (For MCP402X Compatibility).
Note: This command allows compatibility with
the MCP402X family, which supports
updating of the non-volatile wiper setting
with the WiperLock Technology feature.
Note: The wiper value will not underflow. That is,
once the wiper value equals 0x00,
subsequent decrement commands are
ignored.
U/D
CS
Wiper
1 2 3 4
X-1
X
X-2 X-3 X-4
V
IHH
V
IH
V
IH
5
6
V
IL
V
IH
V
IL