DA9191A.000
July 31, 1997
FUNCTIONS
Register 04HEX (bits 7-4 write only, bits 3-0 read only)
Bit
3-0
Name
DTMF[3:0]
State
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
0000
Function
‘1’ Tone detected
‘2’ Tone detected
‘3’ Tone detected
‘4’ Tone detected
‘5’ Tone detected
‘6’ Tone detected
‘7’ Tone detected
‘8’ Tone detected
‘9’ Tone detected
‘0’ Tone detected
‘*’ Tone detected
‘#’ Tone detected
‘A’ Tone detected
‘B’ Tone detected
‘C’ Tone detected
‘D’ Tone detected
6-4
Vref[2:0]
Internal reference voltage adjustment
000
001
010
011
100
101
110
111
0
+0.75dB
+0.50dB
+0.25dB
0.00dB default value
-0.25dB
-0.50dB
-0.75dB
-1.00dB
reserved for future use, set to 0
7
reserved
Register 05HEX (write only)
Bit
Name
State
Function
5-0
LOWF[5:0]
00H-3FH
Transmitted low frequency DTMF tone
Nominal
Real frequency
000000
100110
101010
101111
110011
00
No signal
697 Hz
770 Hz
852 Hz
941 Hz
No signal
695.8 Hz
769.0 Hz
860.6 Hz
933.8 Hz
7-6
reserved
reserved for future use, set to 0
25
MAS [ MICRO ANALOG SYSTEMS ]
