11
11-2
Ver.0.10
A-D CONVERTERS
11.1 Outline of A-D Converters
11.1 Outline of A-D Converter
The 32170 contains two 10-bit A-D converters of a successive approximation type (A-D0 and A-D1
converters). These converters have 32 analog input pins (channels) AD0IN0 to AD0IN15 and
AD1IN0 to AD1IN 15. The A-D conversion results can be read out in either 8 bits or 10 bits.
For A-D conversion, there are following conversion modes and operation modes:
(1) Conversion mode
A-D conversion mode: Ordinary mode in which analog input voltages are converted into digital
quantities.
Comparator mode (Note): A mode in which analog input voltage is compared with a preset
comparison voltage to only find the relative magnitude of two quantities. (Single mode only)
(2) Operation mode
Single mode: Analog input voltage in one channel is A-D converted once or comparated(note)
with a given quantity.
Scan mode: Analog input voltages in multiple selected channels (4, 8, or 16 channels) are
sequentially A-D converted.
(3) Types of scan modes
Single-shot scan mode: Scan operation is performed for one machine cycle.
Continuous scan mode: Scan operation is performed repeatedly until stopped.
(4) Special operation mode
Forcible single mode execution during scan mode: Conversion is forcibly executed in single
mode during scan operation.
Scan mode start after single mode execution: Scan operation is started subsequently after
executing conversion in single mode.
Conversion restart: A-D conversion being executed in single or scan mode is restarted.
The A-D conversion and comparate rates can be selected between normal and double rate. An A-
D conversion interrupt request or a DMA transfer request (for the A-D0 converter only) can be
generated at completion of A-D conversion, comparate operation, single-shot scan operation, or
one cycle of continuous scan operation.
Note:
To discriminate between the comparison operation performed internally by the successive
approximation-type A-D converter and the operation in comparator mode performed using the A-D
converter as a comparator, the comparison operation in comparator mode in this manual is referred to
as "comparate."