UPD70F3116 Datasheet, PDF (642/826 Pages) NEC – 32-Bit Single-Chip Microcontrollers

CHAPTER 13 A/D CONVERTER
13.1 Features
• Two 10-bit resolution on-chip A/D converters (A/D converter 0 and 1)
Simultaneous sampling by two circuits is possible.
• Analog input: 8 channels per circuit
• On-chip A/D conversion result registers 0n, 1n (ADCR0n, ADCR1n)
10 bits × 8 registers × 2
• A/D conversion trigger mode
A/D trigger mode
A/D trigger polling mode
Timer trigger mode
External trigger mode
• Successive approximation technique
• Voltage detection mode
Remark n = 0 to 7
13.2 Configuration
A/D converters 0 and 1, which employ a successive approximation technique, perform A/D conversion operation
using A/D scan mode registers 00, 01, 10, and 11 (ADSCM00, ADSCM01, ADSCM10, and ADSCM11) and registers
ADCR0n and ADCR1n (n = 0 to 7).
(1) Input circuit
The input circuit selects an analog input (ANI0n or ANI1n) according to the mode set in the ADSCM00 or
ADSCM10 register and sends it to the sample and hold circuit (n = 0 to 7).
(2) Sample and hold circuit
The sample and hold circuit individually samples analog inputs sent sequentially from the input circuit and
sends them to the comparator. It holds sampled analog inputs during A/D conversion.
(3) Voltage comparator
The voltage comparator compares the analog input voltage that was input with the output voltage of the D/A
converter.
(4) D/A converter
The D/A converter is used to generate a voltage that matches an analog input.
The output voltage of the D/A converter is controlled by the successive approximation register (SAR).
(5) Successive approximation register (SAR)
The SAR is a 10-bit register that controls the output value of the D/A converter for comparing with an analog
input voltage value. When an A/D conversion terminates, the current contents of the SAR (conversion result)
are stored in an A/D conversion result register (ADCR0n, ADCR1n) (n = 0 to 7). When all specified A/D
conversions terminate, there also is an A/D conversion termination interrupt (INTAD0, INTAD1).
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User’s Manual U14492EJ5V0UD