RL78/G1P
(5) Successive approximation register (SAR)
The SAR register is a register that sets voltage tap data whose values from the comparison voltage generator match
the voltage values of the analog input pins, 1 bit at a time starting from the most significant bit (MSB).
If data is set in the SAR register all the way to the least significant bit (LSB) (end of A/D conversion), the contents of
the SAR register (conversion results) are held in the A/D conversion result register (ADCR). When all the specified
A/D conversion operations have ended, an A/D conversion end interrupt request signal (INTAD) is generated.
(6) 12-bit A/D conversion result register (ADCR)
The A/D conversion result is loaded from the successive approximation register to this register each time A/D
conversion is completed, and the ADCR register holds the A/D conversion result in its lower 12 bits (the higher 4 bits
are fixed to 0).
(7) 8-bit A/D conversion result register (ADCRH)
The A/D conversion result is loaded from the successive approximation register to this register each time A/D
conversion is completed, and the ADCRH register stores the higher 8 bits of the A/D conversion result.
(8) Controller
This circuit controls the conversion time of an input analog signal that is to be converted into a digital signal, as well
as starting and stopping of the conversion operation. When A/D conversion has been completed, this controller
generates INTAD through the A/D conversion result upper limit/lower limit comparator.
(9) AV
pin
REFP
This pin inputs an external reference voltage (AV
If using AV
as the + side reference voltage of the A/D converter, set the ADREFP1 and ADREFP0 bits of A/D
REFP
converter mode register 2 (ADM2) to 1.
The analog signals input to ANI0 to ANI7 are converted to digital signals based on the voltage applied between
and the side reference voltage (AV
AV
REFP
In addition to AV
REFP
voltage of the A/D converter.
(10) AV
pin
REFM
This pin inputs an external reference voltage (AV
converter, set the ADREFM bit of the ADM2 register to 1.
In addition to AV
, it is possible to select V
REFM
R01UH0895EJ0100 Rev.1.00
Nov 29, 2019
REFM
, it is possible to select V
SS
).
REFP
/V
).
SS
, or the internal reference voltage (1.45 V) as the + side reference
DD
). If using AV
REFM
REFM
as the side reference voltage of the A/D converter.
CHAPTER 9 A/D CONVERTER
as the side reference voltage of the A/D
245