
23 A/D Converter (ADC10SA)
S1C17003 TECHNICAL MANUAL
EPSON
23-7
ADC10SA
When the serial conversion mode has been selected, conversion result must be read from ADD[15:0] before
the next conversion is completed. If you cannot read the conversion result before ADD[15:0] is updated while
the conversion complete flag ADCF (D8/ADC10_CTL register) is set to 1, the overwrite error flag ADOWE
(D9/ADC10_CTL register) is set to 1, so that you can check that the conversion result has been overwritten.
You can also generate the conversion data overwrite interrupt concurrently with overwriting. After reading the
conversion result from ADD[15:0], read also the ADOWE flag, or check that the conversion data overwrite
interrupt has not occurred so that the read data is valid.
Once the ADOWE flag has been set, it is not reset until software write 1 to the flag. If the ADOWE flag has
been reset, the conversion data overwrite interrupt can be stopped to occur.
Note that setting ADOWE flag to 1 also sets the ADCF flag. Therefore, read converted data to reset ADCF to 0.
ADOWE: Overwrite Error Flag Bit in the ADC10 Control/Status (ADC10_CTL) Register (D9/0x5384)
Note: Occurrence of an overwrite error does not stop serial conversion process.
Completing A/D conversion
For single conversion mode (ADMS=0)
Single conversion mode stops the conversion process once completing a cycle from the start channel specified
by ADCS[2:0] (D[10:8]/ADC10_TRG register) to the end channel ADCE[2:0] (D[13:11]/ADC10_TRG
register). After the completion, ADCTL (D1/ADC10_CTL register) is returned to 0.
ADMS: Conversion Mode Selection bit in the ADC10 Trigger/Channel Select (ADC10_TRG) Register
(D6/0x5382)
For serial conversion mode (ADMS=1)
Serial conversion mode maintains the A/D conversion cycles from the start channel to the end channel
continuously. Hardware in this mode does not stop the cycles. Use software to set ADCTL (D1/ADC10_CTL
register) to 1 to terminate the process forcibly. You cannot get data under A/D conversion process when forcible
termination occurs.