NEC 78K0S/KA1+ User Manual page 159

(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) AV pin
REF
This pin inputs an analog power/reference voltage to the A/D converter. When the A/D converter is not used,
connect this pin to V
DD
The signal input to ANI0 to ANI3 is converted into a digital signal, based on the voltage applied across AV
V .
SS
(10) V pin
SS
This is the ground potential pin.
In the 78K0S/KA1+, V
V to a stabilized GND (= 0 V).
SS
(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 to P23/ANI3 pins are used as the analog input pins of the A/D converter.
CHAPTER 10 A/D CONVERTER
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functions alternately as the ground potential of the A/D converter. Be sure to connect
SS
User's Manual U16898EJ3V0UD
and
REF
159