5 high-priority conversion mode, 6 ad monitor function, 7 ad conversion time – Toshiba H1 Series User Manual

Page 614

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TMP92CZ26A

92CZ26A-611

3.23.2.5 High-Priority

Conversion

Mode

The ADC can perform a high-priority AD conversion while it is performing a normal

AD conversion sequence. A high-priority AD conversion can be started at software by
setting the ADMOD2<HADS> to “1”. It is also triggered by a hardware trigger if so
enabled using ADMOD2<HTSEL1:0>. If a high-priority AD conversion is triggered
during a normal AD conversion, the ADC aborts any ongoing conversion immediately,
and then begins a single high-priority AD conversion for the channel specified with the
ADMOD3<HADC2:0>. Upon the completion of the high-priority AD conversion, the
ADC stores the results of the conversion in the ADREGSPH/L, generates the
high-priority AD conversion interrupt (INTADHP), and then resumes the suspended
normal conversion with that channel. While a high-priority conversion is being
performed, a trigger for another high-priority conversion is ignored.

Example: In the case of a high-priority AD conversion for AN5 (ADMOD3<HADCH2:0>=”101”) is started durring a

normal AD conversion in channel scan repeat mode for AN0 to AN3 (ADMOD1<REPEAT,SCAN>

= “11”

ADMOD1<ADCH2:0>

= “011”)

3.23.2.6

AD Monitor Function

When ADMOD4<CMEN1:0> is set to “1”, the AD monitor function is enabled. This

function generates an interrupt depending on condition of IRQEN1:0, when the
finished AD conversion of the channel which specified with the ADMOD5 register, if
the value of the AD conversion result register pair is greater or less (specified with
CMP1C:0C) than the value of the compare criterion register 0/1(ADCMxREGH/L).
The ADC performs this comparison each times it stores results to the specified AD
conversion result register and generate interrupt (INTADM) when condition is
satisfied. The conversion result register used for the AD monitor function is usually
not read in the program, so mind that its overrun flag <OVRn> and conversion result
store flag <ADRnRF> are always set.

If these are assigned to different channel, 2-analog channel can monitor “less” or

“grater”. And if these are assigned same analog channel, the watch that sets the range
of the voltage is possible.

3.23.2.7 AD

Conversion

Time

AD conversion of one time is 120 clocks that include sampling clock. The AD

conversion clock can be selected from 1/1 to 1/7 of f

IO

by ADCLK<ADCLK2:0>. To

assure conversion accuracy, the AD conversion clock frequency need to select 12 MHz
and under, i.e., AD conversion time need to select 10 µs and over.

AN0 AN1 AN2 AN5 AN2 AN3 AN0

High-priority AD

conversion start trigger

Conversion channel

Abort conversion

for AN2

Start conversion for AN5

conversion for AN2

again

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