TMPM330 - Keil

Under development
TMPM330 (rev 0.4) 13-17
TMPM330
13.4.3 Starting A/D Conversion
Two types of A/D conversion are supported: normal AD conversion and top-priority AD
conversion. Normal AD conversion is software activated by setting ADMOD0 to
"1." Top-priority AD conversion is software activated by setting ADMOD2 to
"1." 4 operation modes are made available to normal AD conversion. In performing
normal AD conversion, one of these operation modes must be selected by setting
ADMOD0 to an appropriate setting. For top-priority AD conversion, only one
operation mode can be used: fixed channel single conversion mode. Normal AD
conversion can be activated using the HW activation source selected by
ADMOD3, and top-priority AD conversion can be activated using the HW
activation source selected by ADMOD3. If this bit is "0," normal and top-priority
AD conversions are activated in response to the input of a falling edge through the
ADTRG pin. If this bit is "1," normal AD conversion is activated in response to TB1RG6
generated by the 16-bit timer 6, and top-priority AD conversion is activated in response to
TB2RG5 generated by the 16-bit timer 5. Software activation is still valid even after H/W
activation has been authorized.
(Note) When an external trigger is used for the HW activation source of a top priority analog
to digital translation, an external trigger cannot usually be set as analog to digital
translation HW activation.
(Note) The TMPM330 disables the external trigger used for H/W activation. Therefore “0”
cannot be set to and .
When normal A/D conversion starts, the A/D conversion Busy flag (ADMOD0)
showing that A/D conversion is under way is set to "1." When top-priority A/D conversion
starts, the A/D conversion Busy flag (ADMOD2) showing that A/D
conversion is under way is set to "1." At that time, the value of the Busy flag for normal
A/D conversion before the start of top-priority A/D conversion is retained. The value of
the conversion completion flag EOCFN for normal A/D conversion before the start of
top-priority A/D conversion can also be retained.
(Note) Normal A/D conversion must not be activated when top-priority A/D conversion is
under way. In that case, the top-priority A/D conversion completion flag cannot be
set, and the flag for previous normal A/D conversion cannot be cleared.
To reactivate normal A/D conversion while the conversion is under way, a software reset
(ADMOD4) must be performed before starting A/D conversion. The HW
activation method must not be used to reactivate normal A/D conversion.
If ADMOD2 is set to "1" during normal A/D conversion, ongoing A/D
conversion is discontinued and top-priority A/D conversion starts; specifically, A/D
conversion (fixed channel single conversion) is executed for a channel designated by
ADMOD2. After the result of this top-priority A/D conversion is stored in the storage
register ADREGSP, normal A/D conversion is resumed.
Analog/ Digital Converter