TMP19A71
13.3.1.1
Starting of AD Conversion
AD conversion has two types; Normal AD conversion and Highest-Priority AD conversion.
A Normal AD conversion starts up in software by setting 1 to ADCSTART0<ADSFT>. Also,
the Highest-Priority conversion starts up in software by setting 1 to ADCHPC0<HPRQ>. A
For Normal AD conversion, one operating mode among the four operating modes specified by
ADNMOD0<REP:SCAN>. An operating mode of the Highest-Priority conversion is
Channel-Fixed Single conversion only. A Normal AD conversion can start up with hardware
starting source selected by ADNMOD0<TSEL> by setting 1 to ADNMOD0<TRGE>. When
this bit is “10/11,” a Normal AD conversion starts up at the rising edge of ADTRG0 pin, and
when “01,” it starts up with INTTBCOM11 of the timer from 16-bit quantity. It can start in
software even if the startup in hardware becomes enabled.
When a Normal AD conversion starts, 1 is set to an AD conversion Busy flag
(ADCSTART0<BUSY>) indicating that the conversion is in progress. When the
Highest-Priority AD conversion starts, 1 is set to an AD conversion Busy flag
(ADCHPC0<HBSY>). At this time, a Busy flag for Normal AD conversion retains the value
before a starting of the Highest-Priority AD conversion. A conversion end flag
ADCSTART0<EOS> for Normal AD conversion, also, retains the value before a starting of
the Highest-Priority AD conversion. Since ADCSTART0<BUSY> is a flag showing the
conversion operation, it has an interval of being 0 between the conversions such as those in
the Continuous conversion mode. When palling the end of conversion, ADCSTART0<EOS>
must not be used.
When 1 is set to ADCHPC0<HPRQ> during a Normal AD conversion, the
Highest-Priority AD conversion starts upon the storage of result register of the ongoing
conversion, and AD conversion (Channel-Fixed Single conversion) of the cannel specified by
ADCHPC0<HPCH> starts. When this result is stored in the result register ADCHPR0, a
Normal AD conversion resumes operation from the part suspended.
13.3.1.2
Restart
A Normal AD conversion restarts when 1 is set to ADCSTART0<ADSFT0> during the
Channel-Fixed Normal Conversion, or it is started with hardware source. At the time of
restarting, a Normal AD conversion performed till then starts conversion after a lapse of
conversion time, however, the result that has been converted at the moment of restarting is
not stored. Restarting does clear neither the flags of <OVRx> nor <VALx>.
Note 1: When Continuous conversion is in process, stop it first (ADNMOD0<REP>=0) and restart after all of the conversions
ended.
Note 2: When Channel Scan mode conversion is in process, restart after all of the conversions ended.
13.3.1.3
Stop Repeat
Changing the ADNMOD0 bit in <REP> from 1 to 0 enables the stop of repeating after the
Continuous conversion made one-cycle repeat. In Channel-Fixed Continuous conversion
mode (interrupts after four conversions), as an interrupt generates after conversion is
performed four times, the Continuous conversion stops. In Channel Scan Continuous
conversion mode, after the conversions performed as much as specified number of channels,
the Continuous conversion stops as an interrupt is generated.
TMP19A71
13-15