MC68HC05P9A Datasheet, PDF (124/158 Pages) Freescale Semiconductor, Inc – HCMOS Microcontroller Unit

ADC
Freescale Semiconductor, Inc.
CH[2:0] — Channel Select Bits
These read/write bits select one of eight ADC input channels as
shown in Table 26. Channels 0–3 are the input pins, PC3/AN3,
PC4/AN2, PC5/AN1, and PC6/AN0. Channels 4–6 can be used for
reference measurements. Channel 7 is reserved for factory testing.
Table 26. ADC Input Channel Selection
CH[2:1:0]
Channel
Signal
000
0
AN0
001
1
AN1
010
2
AN2
011
3
AN3
100
4
V_RH (see Note 1)
101
5
(V_RH + V_SS) / 2
(see Note 1)
110
6
V_SS (see Note 1)
111
7
Reserved
NOTE:
1. The accuracy of these measurements are
untested and not guaranteed.
To prevent excess power dissipation, do not use an ADC pin as an
analog input and a digital input at the same time.
Using one of the port pins as the ADC input does not affect the ability to
use the remaining port pins as digital inputs.
Reading a port pin that is selected as an analog input returns a logic 0.
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ADC
MOTOROLA
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