4524_M Datasheet, PDF (214/310 Pages) Renesas Technology Corp – 4-BIT CISC SINGLE-CHIP MICROCOMPUTER 720 FAMILY / 4500 SERIES

4524 Group
APPLICATION
2.4 A/D converter
2.4 A/D converter
The 4524 Group has an 8-channel A/D converter with the 10-bit successive comparison method.
This A/D converter can also be used as a comparator to compare analog voltages input from the analog
input pin with preset values.
This section describes the related registers, application examples using the A/D converter and notes.
Figure 2.4.1 shows the A/D converter block diagram.
Register B (4)
IAP2
(P20–P23)
IAP3
(P30–P33)
OP2A
(P20–P23)
OP3A
(P30–P33)
P20/AIN0
P21/AIN1
P22/AIN2
P23/AIN3
P30/AIN4
P31/AIN5
P32/AIN6
P33/AIN7
Register A (4)
4 ^TAQ1
TQ1A
4 ^TAQ2
TQ2A
4 ^TAQ3
TQ3A
Q13 Q12 Q11 Q10 Q23 Q22 Q21 Q20 ^Q33 Q32 Q31 Q30
Instruction clock
1/6
44
44
2
TALA
8
TABAD
8
TADAB
3
Q13
0
A/D control circuit
1
ADF
(1)
A/D
interrupt
1
Comparator
Successive comparison
0
register (AD) (10)
Q13
10
10
DAC
operation
signal
01
Q13
Q13
8
01
1
8
DA converter
(Note 1)
VDD
VSS
Comparator register (8)
(Note 2)
88
Notes 1: This switch is turned ON only when A/D converter is operating and generates the comparison voltage.
2: Writing/reading data to the comparator register is possible only in the comparator mode (Q13=1).
The value of the comparator register is retained even when the mode is switched to the A/D conversion
mode (Q13=0) because it is separated from the successive comparison register (AD). Also, the resolution
in the comparator mode is 8 bits because the comparator register consists of 8 bits.
Fig. 2.4.1 A/D converter structure
Rev.2.00 Aug, 06 2004
REJ09B0107-0200Z
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