Specifications

ADC Overview
7-7 Analog-to-Digital Converter (ADC)
The sequencer operation for both 8-state and 16-state modes is almost identi-
cal; the few differences are highlighted in Table 7–2.
Table 7–2. Comparison of Single and Cascaded Operating Modes
Feature
Single 8-state
sequencer #1 (SEQ1)
Single 8-state
sequencer #2 (SEQ2)
Cascaded 16-state
sequencer (SEQ)
Start of conversion
triggers
EVA, software,
external pin
EVB, software EVA, EVB, software,
external pin
Maximum number of
autoconversions
(i.e., sequence length)
8816
Autostop at end of
sequence (EOS)
Yes Yes Yes
Arbitration priority High Low Not applicable
ADC conversion result
register locations
0 to 7 8 to 15 0 to 15
CHSELSEQn bit field
assignment
CONV00 to CONV07 CONV08 to CONV15 CONV00 to CONV15
For convenience, the sequencer states will be subsequently referred to as:
- For SEQ1: CONV00 to CONV07
- For SEQ2: CONV08 to CONV15
- For Cascaded SEQ: CONV00 to CONV15
The analog input channel selected for each sequenced conversion is defined
by CONVnn bit fields in the ADC Input Channel Select Sequencing Control
Registers (CHSELSEQn). (See section 7.6.5.) CONVnn is a 4-bit field that
specifies any one of the 16 channels for conversion. Since a maximum of
16 conversions in a sequence is possible when using the sequencers in cas-
caded mode, 16 such 4-bit fields (CONV00 – CONV15) are available and are
spread across four 16-bit registers (CHSELSEQ1 – CHSELSEQ4). The
CONVnn bits can have any value from 0 – 15. The analog channels can be
chosen in any desired order and the same channel may be selected multiple
times.
7.2.2 Basic Operation
The following description applies to the 8-state sequencers (SEQ1 or SEQ2).
In this mode, SEQ1/SEQ2 can “autosequence” up to eight conversions of any
channel in a single sequencing session. The result of each conversion is