Figure 13.3.3 A/D Data Register (Adcd) - Fujitsu F2MC-8L MB89620 Series Hardware Manual

13.3 Structure of A/D Converter
13.3.3 A/D Data Register (ADCD)
The A/D data register stores the A/D conversion result for the A/D conversion function.
The compare voltage data is written to this register for the sense function.
n A/D Data Register (ADCD)
Figure 13.3.3 shows the bit structure of the A/D data register (ADCD).
R : Read-only
W : Write-only
— : Unused
X : Indeterminate
For A/D conversion function
l
The conversion result is decided approximately 44 instruction cycles after A/D conversion is
activated. The data of conversion is stored in this register. The value of the register is
indeterminate while A/D conversion is in progress. The register is read-only for the A/D
conversion function.
For sense function
l
Before activating the sense function, set the data corresponding to the voltage to be compared
(compare voltage).
As the register is write-only when the sense function is selected, bit manipulation instructions
cannot be used. Confirm operation stopped (ADC2: EXT = "0", ADC1: ADMV = "0") before
writing to this register.
n Example of ADCD Register Setting for Sense Function
Table 13.3.3 Example of ADCD Register Setting for Sense Function
ADCD register set value
Condition: AV
254
CHAPTER 13 A/D CONVERTER
Address Bit 7 Bit 6
0022
H
R R
W W

Figure 13.3.3 A/D Data Register (ADCD)

= AVR = 5.0 V, AV
CC SS
Bit 5 Bit 4 Bit 3 Bit 2
R R R
W W W
5.0 4.0
FF CD
H H
= 0.0 V
Bit 1 Bit 0 Initial value
XXXXXXXX
R R R
······For the A/D conversion function
W W W
······For the sense function
Compare voltage (V)
3.0 2.0
9A 66
H H
B
1.0 0.0
33 00
H H
MB89620 series