Cypress S6J3200 Series, Руководство пользователя

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CHAPTER 15:12-/10-/8-bit Analog to Digital Converter
254 S6J3200 Series Hardware Manual Document Number: 002-04852 Rev. *G
1.
Overview
The A/D Converter converts analog input voltages into digital values. The A/D Converter features eight
range comparators, 64 pulse detection units, 64 separate conversion data registers and four multiple
conversion channels.
Features of the A/D Converter

Conversion time: Refer to the datasheet

12-/10-/8-bit resolution

RC type successive approximation conversion with sample & hold circuit

Programmable configuration of 64 logical channels by mapping them to up to 64 analog inputs
−
Each logical channel is mapped to exactly one analog input
−
Several logical channels can be mapped to the same analog input

64 dedicated logical channel conversion data registers

Programmable selection of one of the four global sampling times for each logical channel

Conversion request for each logical channel i is possible by software trigger only, hardware or software
trigger, trigger by conversion completion of the preceding logical channel i-1 and idle trigger

All active conversion requests are compared according to the corresponding logical channel priorities
(selectable range is 0-15, 0 is the highest and 15 is the lowest priority) and A/D conversion is started for
the logical channel with the highest priority

When the higher priority conversion requests during an active A/D conversion, it is possible to select the
following behavior
−
An active A/D conversion can be interrupted, and the higher priority conversion starts after interrupt
operation
−
An active A/D conversion cannot be interrupted, hence the wait time between the higher priority
conversion request and its conversion start can be up to the maximum A/D conversion period. In
case of multiple conversion channel processing that are configured to be non-interruptible, the wait
time can increase to the time needed to the maximum multiple channel conversion period

The consecutive logical channels can be configured as a group, where the start channel conversion
request is set to software trigger only, hardware or software trigger or idle trigger while all other channel
conversion requests are set to the preceding logical channel conversion completion

If a group conversion is interrupted by a higher priority conversion request, after the higher priority
request is processed the following group configurations are possible:
−
Resume with the next logical channel in the group (before the conversion start of the channel the
group is interrupted)
−
Restart with the group start channel or the last converted channel configured as "resume" channel
within a group
−
Stop the group processing until next start channel conversion request is issued

First four logical channels can be configured as:
−
Multiple conversion channels offering the possibility to perform 1 to 16 conversions of the same
logical channel and accumulate the result
−
A/D Converter calibration channels providing the configuration for conversion of A/D Converter
reference voltages in order to calculate the offset and gain corrections

Eight range comparators are selectable for every logical channel, comparing the full range
(12-bit)/upper 8-bit of the conversion result

Programmable upper and lower thresholds for each range comparator

The comparison results will set flags per logical channel, depending on the configuration. Possible
configurations are: