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User’s Manual U14701EJ3V0UD
CHAPTER 12 A/D CONVERTER
12.1 A/D Converter Functions
The A/D converter is a 10-bit resolution converter that converts analog inputs into digital signals. It can control
up to 10 analog input channels (ANI0 to ANI9).
(1) Hardware start
Conversion is started by trigger input (ADTRG: rising edge, falling edge, or both rising and falling edges can
be specified).
(2) Software start
Conversion is started by setting A/D converter mode register 0 (ADM0).
Select one channel for analog input from ANI0 to ANI9 to start A/D conversion. In the case of hardware start, the
A/D converter stops when A/D conversion is completed, and an interrupt request (INTAD0) is generated. In the case
of software start, A/D conversion is repeated. Each time an A/D conversion operation ends, an interrupt request
(INTAD0) is generated.
Figure 12-1. A/D Converter Block Diagram
Note
The valid edge is specified by bit 3 of the EGP and EGN registers (see
Figure 18-5 External Interrupt
Rising Edge Enable Register (EGP), External Interrupt Falling Edge Enable Register (EGN) Format
).
ANI0/P10
ANI1/P11
ANI2/P12
ANI3/P13
ANI4/P14
ANI5/P15
ANI6/P16
ANI7/P17
ANI8
ANI9
Sample & hold circuit
Series resistor string
Voltage comparator
Controller
Edge
detector
ADTRG/INTP3/P03
4
A/D conversion result
register 0 (ADCR0)
V
DD1
AV
REF0
AV
SS0
INTAD0
INTP3
Trigger enable
A/D converter
mode register 0 (ADM0)
Analog input channel
specification register 0 (ADS0)
Internal bus
ADS02ADS01 ADS00
ADCS0
TRG0 FR02 FR01 FR00
EGA01 EGA00
S
T
Edge
detector
Note
Successive
approximation
register (SAR)
ADS03
ADCE0