MC68HC11P2 Datasheet, PDF (180/268 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Analog-to-Digital Converter
9.5 Channel assignments
The multiplexer allows the A/D converter to select one of sixteen analog
signals. Eight of these channels correspond to port E input lines to the
MCU, four others are internal reference points or test functions; the
remaining four channels are reserved. Refer to Table 9-1.
Table 9-1. A/D converter channel assignments
Channel
number
1
2
3
4
5
6
7
8
9–12
13
14
15
16
Channel
signal
AN0
AN1
AN2
AN3
AN4
AN5
AN6
AN7
reserved
V_RH(1)
V_RL*
V_RH/2^*
reserved^*
1. Used for factory testing.
Result in ADRx
if MULT = 1
ADR1
ADR2
ADR3
ADR4
ADR1
ADR2
ADR3
ADR4
—
ADR1
ADR2
ADR3
ADR4
9.5.1 Single-channel operation
There are two types of single-channel operation. In the first type (SCAN
= 0), the single selected channel is converted four consecutive times.
The first result is stored in A/D result register 1 (ADR1), and the fourth
result is stored in ADR4. After the fourth conversion is complete, all
conversion activity is halted until a new conversion command is written
to the ADCTL register. In the second type of single-channel operation
(SCAN = 1), conversions continue to be performed on the selected
channel with the fifth conversion being stored in register ADR1
(overwriting the first conversion result), the sixth conversion overwriting
Technical Data
Analog-to-Digital Converter
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MC68HC11P2 — Rev 1.0