Hitachi H8/3637 Hardware Manual page 352

DTCR—DTMF control register
Bit
DTEN
Initial value
Read/Write R/W
Column output enable
0
1
DTMF generator enable
0 DTMF generator is halted
1 DTMF generator operates
7 6 5
— CLOE
0 1 0
—
R/W
DTMF column signal output frequency 1 and 0
CLF1 CLF0
0
1
Row output enable
0 DTMF row signal output is disabled (high-impedance)
1 DTMF row signal output is enabled
DTMF column signal output is disabled (high-impedance)
DTMF column signal output is enabled
4 3
RWOE CLF1
0 0
R/W R/W
DTMF row signal output frequency 1 and 0
RWF1
RWF0 DTMF row signal output frequency
0 0 697 Hz (R1)
1 770 Hz (R2)
1 0 852 Hz (R3)
1 941 Hz (R4)
DTMF column signal output frequency
0 1209 Hz (C1)
1 1336 Hz (C2)
0 1447 Hz (C3)
1 1633 Hz (C4)
H'B2 DTMF generator
2 1
CLF0 RWF1
0 0
R/W R/W
0
RWF0
0
R/W
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