A/D Converter Operation - Fujitsu FR60 Hardware Manual

CHAPTER 12 A/D CONVERTER

12.3 A/D Converter Operation

The A/D converter operates using the successive approximation conversion method
and has a 10-bit resolution.
Upon completion of each conversion, this A/D converter stores the upper eight bits in
the 8-bit conversion result register (ADCR0 to ADCR3) for the corresponding channel.
To read a conversion result, read the corresponding conversion result register
(ADCR0 to ADCR3).
The A/D converter has three modes: single-shot conversion mode, continuous
conversion mode, and stop conversion mode. This section describes the operation of
these modes.
■ Single-shot Conversion Mode
This mode sequentially converts the analog input specified by the ANS and ANE bits and stops
operation after performing conversion up to the end channel specified by the ANE bit.
The one-channel conversion operation occurs when the start and end channels are the same
(ANS=ANE).
Example:
If ANS=000
Beginning --> AN0 --> AN1 --> AN2 --> AN3 --> End
If ANS=010
Beginning --> AN2 --> End
Note:
When the A/D conversion mode selection bits (MD1 and MD0) are set to "00
conversion is enabled. In this mode, software start (STS1 and STS0 = 00
Restart in the following procedures.
(1) Clear the INTE bit to "0".
(2) Write the STRT bit to "1" and the INTE bit to "0" at the same time.
When the A/D conversion mode selection bits (MD1 and MD0) are set to "01
conversion is disabled. When restarting and ending of A/D conversion occurred simultaneously,
restart operation is not executed, A/D conversion is terminated, and "300
register (ADCR1/ADCR0). Therefore, perform restart operation not to generate restarting and
ending of A/D conversion simultaneously.
356
, ANE=011 :
B B
, ANE=010 :
B B
", restart during A/D
B
) can only be set.
B
", restart during A/D
B
" is stored in the data
H