C8051F2XX Datasheet, PDF (34/146 Pages) Silicon Laboratories – Mixed Signal 8 kB ISP Flash MCU Family

C8051F2xx
SFR Definition 5.1. AMX0SL: AMUX Channel Select
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Reset Value
-
-
AMXEN PRTSL1 PRTSL0 PINSL2 PINSL1 PINSL0 00000000
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
SFR Address:
0xBB
Bits 7–6: UNUSED. Read = 00b; Write = don't care
Bit 5: AMXEN enable
0: AMXEN disabled and port pins are unavailable for analog use.
1: AMXEN enabled to use/select port pins for analog use.
Bits 4–3: PRTSL1–0: Port Select Bits*.
00: Port0 select to configure pin for analog input from this port.
01: Port1 select to configure pin for analog input from this port.
10: Port2 select to configure pin for analog input from this port.
11: Port3 select to configure pin for analog input from this port.
Bits 2–0:PINSL2–0: Pin Select Bits
000: Pin 0 of selected port (above) to be used for analog input.
001: Pin 1 of selected port (above) to be used for analog input.
010: Pin 2 of selected port (above) to be used for analog input.
011: Pin 3 of selected port (above) to be used for analog input.
100: Pin 4 of selected port (above) to be used for analog input.
101: Pin 5 of selected port (above) to be used for analog input.
110: Pin 6 of selected port (above) to be used for analog input.
111: Pin 7 of selected port (above) to be used for analog input.
* Selecting a port for analog input does NOT default all pins of that port as analog input. After select-
ing a port for analog input, a pin must be selected using pin select bits (PINSL2–0). For example,
after setting the AMXEN to ‘1’, setting PRTSL1–0 to “11”, and setting PINSL2–0 to “100” P3.4 is
configured as analog input. All other Port 3 pins remain as GPIO pins. Also note that in order to use
a port pin as analog input, its input mode should be set to analog. Please see section 14.2.
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Rev. 1.6