Silicon Laboratories SI2493/57/34/15/04 - Manual (Page 102)

A N 9 3
102 Rev. 1.3
5.7.7. U46–U48 (DTMF Dial Registers)
U46–U48 set the DTMF power level, DTMF “on” time, and DTMF “off” time, respectively (see Table 54). The DTMF
power levels are set in register U46 as a 16-bit value with the format 0x0HL0, where H is a hexadecimal number
(0–F) for the dBm level of the high-frequency DTMF tone, and L is a hexadecimal number (0–F) for the dBm level
of the low-frequency DTMF tone. The power level is specified in –1 dB units. The DTMF output level is 0 dBm for
each tone if U46 = 0x0000 and –15 dBm if U46 = 0x0FF0. The default power level is –9 dBm for the high tone and
–11 dBm for the low tone.
U47 and U48 set the DTMF “on” time (DTNT) and “off” time (DTFT) respectively as hexadecimal values in
milliseconds. The default value for both U47 and U48 is 100 ms, and the range of values is 0–1000 ms.
Table 53. Pulse Dial Registers
Register Name Description Default
U37 PD0 Number of pulses to dial 0. 0x000A
U38 PD1 Number of pulses to dial 1. 0x0001
U39 PD2 Number of pulses to dial 2. 0x0002
U3A PD3 Number of pulses to dial 3. 0x0003
U3B PD4 Number of pulses to dial 4. 0x0004
U3C PD5 Number of pulses to dial 5. 0x0005
U3D PD6 Number of pulses to dial 6. 0x0006
U3E PD7 Number of pulses to dial 7. 0x0007
U3F PD8 Number of pulses to dial 8. 0x0008
U40 PD9 Number of pulses to dial 9. 0x0009
U42 PDBT Pulse dial break time (ms units). 0x003D
U43 PDMT Pulse dial make time (ms units). 0x0027
U45 PDIT Pulse dial interdigit time (ms units). 0x0320
Table 54. DTMF Dial Registers
Register Name Description Default
U46 DTPL DTMF power level 0x09B0
U47 DTNT DTMF “on” time (ms units). 0x0064
U48 DTFT DTMF “off” time (ms units). 0x0064