4513_03 Datasheet, PDF (152/210 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.5 A-D converter
2.5 A-D converter
The 4513/4514 Group has an A-D converter with the 10-bit successive comparison method: 4 channels for
the 4513 Group, 8 channels for the 4514 Group.
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 2.5.1 shows the A-D converter block diagram.
Register B (4)
IAP4
(P40—P43)
OP4A
(P40—P43)
(Note 3)
AIN0/CMP0-
AIN1/CMP0+
AIN2/CMP1-
AIN3/CMP1+
P40/AIN4
P41/AIN5
P42/AIN6
P43/AIN7
TAQ2
TQ2A
TAQ1
TQ1A
Q23 Q22 Q21 Q20 Q13 Q12 Q11 Q10
Register A (4)
2
TALA
Instruction clock
1/6
44
44
8
TABAD
8
TADAB
3
Q23
0
A-D control circuit
1
ADF
(1)
A-D interrupt
Comparator
1
0
Q23
Successive comparison
register (AD) (10)
10
10
DAC
operation
signal
01
Q23
8
DA converter
(Note 1)
VSS
Comparator register (8)
VDD
(Note 2)
Q23
8
01
1
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 (Q23=1).
The value of the comparator register is retained even when the mode is switched to the A-D conversion
mode (Q23=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.
3: The 4513 Group does not have ports P40/AIN4–P43/AIN7 and the IAP4 and OP4A instructions.
Fig. 2.5.1 A-D converter structure
4513/4514 Group User’s Manual
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