E202075_HD404889 Datasheet, PDF (129/202 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip LCD Circuit

HD404889/HD404899/HD404878/HD404868 Series
A/D mode register (AMR: $028):
The A/D mode register is a 4-bit write-only register that shows the A/D converter speed setting and
information on the analog input pin specification. The A/D conversion time is selected by bit 0, and the
channel by bits 1, 2, and 3 (figure 74).
A/D start flag (ADSF: $020,2):
A/D conversion is started by writing 1 to the A/D start flag. When conversion ends, the converted data is
placed in the A/D data register and the A/D start flag is cleared at the same time. (figure 75).
A/D mode register (AMR: $028)
Bit
Read/Write
Initial value on reset
Bit name
3
W
0
AMR3
2
W
0
AMR2
1
W
0
AMR1
0
W
0
AMR0
AMR0 _{A/D conversion time}
0
65 tcyc
1
125 tcyc
AMR3 AMR2 AMR1 Analog input channel selection
0
0
*
0
1
1
No selection
AN0
AN1
0
AN2
0
1
AN3
1
0
AN4
1
1
AN5
* : Don't care
Figure 74 A/D Mode Register (AMR)
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