Chapter 4 Register Structure and Format 37
4.6 MUX ControlBASE+4 and BASE+5
Table 4.6: The register for multiplexer control
CL3 ~ CL0 Start Scan Channel Number
CH3 ~ CH0 Stop Scan Channel Number
BASE+4 bit 3 to bit 0, CL3 ~ CL0, act as a pointer when you program
the A/D channel setting (see previous section). When you set the
MUX start channel to an analog input channel, AIn ( n = 0, 1, 2…15 ),
the gain code, B/U and S/D written to the register of BASE+2, is for
channel n.
Caution! We recommend you set the same start and stop
channel when writing to the register BASE+2.
Otherwise, if the A/D trigger source is on, the
multiplexer will continuously scan between channels
and the range setting may be set to an unexpected
channel. Make sure the A/D trigger source is turned
off to avoid this kind of error.
The write-only registers of BASE +4 and BASE+5 control how the
multiplexers (MUXs) scan. BASE+4 bit 3 to bit 0, CL3 ~ CL0, hold
the start scan channel number, and BASE+5 bit 3 to bit 0, CH3 ~ CH0,
hold the stop scan channel number. Writing to these two registers
automatically initializes the scan range of the MUXs. Each A/D
conversion trigger also sets the MUXs to the next channel. With
continuous triggering, the MUXs will scan from the start channel to
Write MUX Control
Bit # 7 6 5 4 3 2 1 0
BASE+5 CH3 CH2 CH1 CH0
BASE+4 CL3 CL2 CL1 CL0