tmp19a44fda TOSHIBA Semiconductor CORPORATION, tmp19a44fda Datasheet - Page 475

• Manufacturer Part Number: tmp19a44fda
• Description: 32bit Tx System Risc
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Analog/Digital Converter
17.3 Description of Operations
Top-priority AD has been activated
Conversion Ch
17.3.1
17.3.2
The "H" level of the analog reference voltage shall be applied to the VREFH pin, and the "L" level shall
be applied to the VREFL pin. By writing "0" to the ADMOD1<VREFON> bit, a switched-on state of
VREFH-VREFL can be turned into a switched-off state. To start AD conversion, make sure that you
first write "1" to the <VREFON> bit, wait for 3 μs during which time the internal reference voltage
should stabilize, and then write "1" to the ADnMOD0<ADS> bit.
How the analog input channel is selected is different depending on A/D converter operation mode used.
(1) Normal AD conversion mode
(2) Top-priority AD conversion mode
After a reset, ADnMOD0<SCAN> is initialized to "0" and ADnMOD1<ADCH3:0> is initialized to
"0000." This initialization works as a trigger to select a fixed channel input through the ANn0 pin. The
pins that are not used as analog input channels can be used as ordinary input ports.
If top-priority AD conversion is activated during normal AD conversion, normal AD conversion is
discontinued, top-priority AD conversion is executed and completed, and then normal AD conversion is
resumed.
Example:
If the analog input channel is used in a fixed state (ADnMOD0<SCAN>="0"):
If the analog input channel is used in a scan state (ADnMOD0<SCAN>="1"):
One channel is selected from analog input pins AINn0 through AINn3 and AINC0 through AINC7
by setting ADnMOD2<HPADCH3 to 0> to an appropriate setting.
Analog Reference Voltage
Selecting the Analog Input Channel
One channel is selected from analog input pins AINn0 through AINn3 and AINC0 through
AINC7 by setting ADnMOD1<ADCH3 to 0> to an appropriate setting.
One scan mode is selected from 16 scan modes by setting ADnMOD1<ADCH3 to 0> and
ADSCN to appropriate settings.
A case in which repeat-scan conversion is ongoing at channels AINC0 through AINC3 with
ADCMOD0 <REPEAT:SCAN> set to "11" and ADCMOD1<ADCH3:0> set to 0011, and
top-priority AD conversion has been activated at AINC7 with
ADCMOD2<HPADCH3:0>=0111:
Ch0
Ch1
TMP19A44(rev1.3) 17-16
Ch2
Ch15
Ch2
Ch3
TMP19A44
Ch0
2010-04-01