UPD78F9500MA-CAC-A Datasheet, PDF (162/342 Pages) Renesas Technology Corp – 8-Bit Single-Chip Microcontrollers

CHAPTER 9 A/D CONVERTER (μPD78F920x ONLY)
(5) Successive approximation register (SAR)
This register compares the sampled analog voltage and the voltage of the D/A converter, and converts the result,
starting from the most significant bit (MSB).
When the voltage value is converted into a digital value down to the least significant bit (LSB) (end of A/D
conversion), the contents of the SAR register are transferred to the A/D conversion result register (ADCR).
(6) 10-bit A/D conversion result register (ADCR)
The result of A/D conversion is loaded from the successive approximation register to this register each time A/D
conversion is completed, and the ADCR register holds the result of A/D conversion in its lower 10 bits (the higher
6 bits are fixed to 0).
(7) 8-bit A/D conversion result register (ADCRH)
The result of A/D conversion is loaded from the successive approximation register to this register each time A/D
conversion is completed, and the ADCRH register holds the result of A/D conversion in its higher 8 bits.
(8) Controller
When A/D conversion has been completed, INTAD is generated.
(9) VDD pin
This is the positive power supply pin.
In the 78K0S/KU1+, VDD functions alternately as the A/D converter reference voltage input. When using the A/D
converter, stabilize VDD at the supply voltage used (2.7 to 5.5 V).
(10) VSS pin
This is the ground potential pin.
In the 78K0S/KU1+, VSS functions alternately as the ground potential of the A/D converter. Be sure to connect
VSS to a stabilized GND (= 0 V).
(11) A/D converter mode register (ADM)
This register is used to set the conversion time of the analog input signal to be converted, and to start or stop the
conversion operation.
(12) Analog input channel specification register (ADS)
This register is used to specify the port that inputs the analog voltage to be converted into a digital signal.
(13) Port mode control register 2 (PMC2)
This register is used when the P20/ANI0/TI000/TOH1, P21/ANI1/TI010/TO00/INTP0, P22/ANI2, and P23/ANI3
pins are used as the analog input pins of the A/D converter.
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User’s Manual U18172EJ3V0UD