请教EMB1432 Multiplexer Addressing Mode的问题

datasheet上有写，如下

CONTROL METHODS
The Multiplexer is a 16:1 single ended output. The selection
of the source is made through either the MUX[3:0] digital input
pins or, if MUX[3:0]=1111b, through the SPI digital interface
as described in the next two sections.

SPI MULTIPLEXER ADDRESSING MODE
To control the EMB1432 using SPI connect the MUX0, MUX1,
MUX2, and MUX3 pins to VIO.

Mux方式速度很快，SPI比MUX可以多控制两路aux输入。