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12.2
Register Descriptions
12.2.1
A/D Result Registers (ADRRH, ADRRL)
Bit
7
6
5
4
3
ADRRH
ADRRL
0
2
1
7
6
5
4
3
0
2
1
Initial value
Read/Write
Not
fixed
R
Not
fixed
R
Not
fixed
R
Not
fixed
R
Not
fixed
R
Not
fixed
R
Not
fixed
R
Not
fixed
R
Not
fixed
R
Not
fixed
R
—
—
—
—
—
—
—
—
—
—
—
—
ADR9 ADR8 ADR7 ADR6 ADR5
ADR2
ADR4 ADR3
ADR1 ADR0
—
—
—
—
—
—
ADRRH and ADRRL together comprise a 16-bit read-only register for holding the results of
analog-to-digital conversion. The upper 8 bits of the data are held in ADRRH, and the lower 2
bits in ADRRL.
ADRRH and ADRRL can be read by the CPU at any time, but the ADRRH and ADRRL values
during A/D conversion are not fixed. After A/D conversion is complete, the conversion result is
stored as 10-bit data, and this data is held until the next conversion operation starts.
ADRRH and ADRRL are not cleared on reset.
12.2.2
A/D Mode Register (AMR)
Bit
Initial value
Read/Write
7
CKS
0
R/W
6
TRGE
0
R/W
5
—
1
—
4
—
1
—
3
CH3
0
R/W
0
CH0
0
R/W
2
CH2
0
R/W
1
CH1
0
R/W
AMR is an 8-bit read/write register for specifying the A/D conversion speed, external trigger
option, and the analog input pins.
Upon reset, AMR is initialized to H'30.