upd78f0103hmca1-5a4-a Renesas Electronics Corporation., upd78f0103hmca1-5a4-a Datasheet - Page 181

• Manufacturer Part Number: upd78f0103hmca1-5a4-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

10.1 Function of A/D Converter
ANI3) with a resolution of 10 bits.
(1) 10-bit resolution A/D conversion
(2) Power-fail detection function
Analog input channel
specification register
(ADS)
The A/D converter converts an analog input signal into a digital value, and consists of up to four channels (ANI0 to
The A/D converter has the following two functions.
ANI0/P20
ANI1/P21
ANI2/P22
ANI3/P23
10-bit resolution A/D conversion is carried out repeatedly for one channel selected from analog inputs ANI0 to
ANI3. Each time an A/D conversion operation ends, an interrupt request (INTAD) is generated.
This function is to detect a voltage drop in a battery. The values of the A/D conversion result (ADCR register
value) and power-fail comparison threshold register (PFT) are compared. INTAD is generated only when a
comparative condition has been matched.
ADS1
2
ADS0
A/D converter mode
register (ADM)
Sample & hold circuit
ADCS
Figure 10-1. Block Diagram of A/D Converter
CHAPTER 10 A/D CONVERTER
FR2
AV
SS
User’s Manual U16846EJ3V0UD
FR1
FR0
Internal bus
Controller
Successive
approximation
register (SAR)
A/D conversion result
Voltage comparator
ADCE
register (ADCR)
PFEN PFCM
Power-fail comparison
mode register (PFM)
Comparator
ADCS bit
threshold register (PFT)
Power-fail comparison
INTAD
AV
AV
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REF
SS