TMP91C824
91C824-179
3.11 Analog/Digital
Converter
The TMP91C824 incorporates a 10-bit successive approximation-type analog/digital converter (A/D
converter) with 8-channel analog input.
Figure 3.11.1 is a block diagram of the A/D converter. The 8-channel analog input pins (AN0 to AN7) are
shared with the input-only port 8 and can thus be used as an input port.
(note): When IDLE2, IDLE1 or STOP mode is selected, so as to reduce the power, with some timings the
system may enter a stand-by mode even though the internal comparator is still enabled. Therefore be
sure to check that A/D converter operations are halted before a HALT instruction is executed.
INTAD
interrupt
AN7 (P87)
AN6 (P86)
AN5 (P85)
AN4 (P84)
AN3/ADTRG (P83)
AN2 (P82)
AN1 (P81)
AN0 (P80)
Comparator
VREFH
VREFL
Mu
lt
ip
le
xe
r
Sample and
Hold
A/D mode control register 1 ADMOD1
ADMOD1
<ADTRGE>
<ADCH2 to ADCH0><VREFON>
Scan
Repeat
Interrupt
Busy
End
Start
+
−
Internal data bus
Channel
Selector
A/D mode control register 0 ADMOD0
<EOCF><ADBF><ITM0><REPEAT><SCAN><ADS>
ADTRG
A/D Conversion Result
Register
ADREG04L to ADREG37L
ADREG04H to ADREG37H
D/A converter
A/D Converter Control
Circuit
Analog input
Figure 3.11.1 Block diagram of A/D converter