TMP91C824
91C824-189
2008-02-20
c.
Channel fixed repeat conversion mode
Setting ADMOD0<REPEAT> and ADMOD0<SCAN> to 10 selects channel
fixed repeat conversion mode.
In this mode, data on one specified channel is converted repeatedly. When
conversion has been completed, ADMOD0<EOCF> is set to 1 and
ADMOD0<ADBF> is not cleared to 0 but held 1. INTAD interrupt request
generation timing is determined by the setting of ADMOD0<ITM0>.
Setting <ITM0> to 0 generates an interrupt request every time an AD
conversion is completed.
Setting <ITM0> to 1 generates an interrupt request on completion of every
fourth conversion.
d.
Channel scan repeat conversion mode
Setting ADMOD0<REPEAT> and ADMOD0<SCAN> to 11 selects channel
scan repeat conversion mode.
In this mode, data on the specified scan channels is converted repeatedly.
When each scan
conversion has been completed, ADMOD0<EOCF> is set to 1
and an INTAD interrupt request is generated. ADMOD0<ADBF> is not cleared
to 0 but held 1.
To stop conversion in a repeat conversion mode (e.g., in cases c. and d.), write a
0 to ADMOD0<REPEAT>. After the current conversion has been completed, the
repeat conversion mode terminates and ADMOD0<ADBF> is cleared to 0.
Switching to a halt state (IDLE2 mode with ADMOD1<I2AD> cleared to 0,
IDLE1 mode or STOP mode) immediately stops operation of the AD converter
even when AD conversion is still in progress. In repeat conversion modes (e.g., in
cases c. and d.), when the halt is released, conversion restarts from the beginning.
In single conversion modes (e.g., in cases a. and b.), conversion does not restart
when the halt is released (The converter remains stopped).
Table 3.11.2 shows the relationship between the AD conversion modes and
interrupt requests.
Table 3.11.2 Relationship between AD Conversion Modes and Interrupt Requests
ADMOD0
Mode
Interrupt Request
Generation
<ITM0> <REPEAT>
<SCAN>
Channel fixed single
conversion mode
After completion of
conversion
X 0 0
Channel scan single
conversion mode
After completion of scan
conversion
X 0 1
Every conversion
0
Channel fixed repeat
conversion mode
Every forth conversion
1
1 0
Channel scan repeat
conversion mode
After completion of every
scan conversion
X 1 1
X: Don’t care