TMP91C824
91C824-185
(3) Starting
A/D
Conversion
To start A/D conversion, write “1” to ADMOD0<ADS> in A/D Mode Control Register 0, or
ADMOD1<ADTRGE> in A/D Mode Control Register 1 and input falling edge on ADTRG pin.
When A/D conversion starts, the A/D Conversion Busy flag ADMOD0<ADBF> will be set to “1”,
indicating that A/D conversion is in progress.
Writing “1” to ADMOD0<ADS> during A/D conversion restarts conversion. At that time, to
determine whether the A/D conversion results have been preserved, check the value of the
conversion data storage flag ADREGxL<ADRxRF>.
During A/D conversion, a falling edge input on the ADTRG pin will be ignored.
(4) A/D conversion modes and the A/D Conversion End interrupt
The 4 A/D conversion modes are:
•
Channel Fixed Single Conversion Mode
•
Channel Scan Single Conversion Mode
•
Channel Fixed Repeat Conversion Mode
•
Channel Scan Repeat Conversion Mode
The ADMOD0<REPET> and ADMOD0<SCAN> settings in A/D Mode Control Register 0
determine the A/D mode setting.
Completion of A/D conversion triggers an INTAD A/D Conversion End interrupt request. Also,
ADMOD0<EOCF> will be set to “1” to indicate that A/D conversion has been completed.
①
Channel Fixed Single Conversion Mode
Setting ADMOD0<REPET> and ADMOD0<SCAN> to “00” selects Channel Fixed Single
Conversion Mode.
In this mode, data on one specified channel is converted once only. When the conversion has been
completed, the ADMOD0<EOCF> flag is set to “1”, ADMOD0<ADBF> is cleared to “0”, and an
INTAD interrupt request is generated.
②
Channel Scan Single Conversion Mode
Setting ADMOD0<REPET> and ADMOD0<SCAN> to “01” selects Channel Scan Single
Conversion Mode.
In this mode, data on the specified scan channels is converted once only. When scan conversion has
been completed, ADMOD0<EOCF> is set to “1”, ADMOD0<ADBF> is cleared to “0”, and an
INTAD interrupt request is generated.