Specifications

AN93

80 Rev. 0.9

3.3.18. U46–U48 (DTMF Dial Registers)

U46–U48 set the DTMF power level, DTMF on time, and DTMF off time, respectively (see Table 40). The DTMF

power level set in register U46 is a 16-bit hexadecimal value with the format 0x0(H)(L)0, 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 difference between the level of the high-frequency tone and the

low-frequency tone is called “twist” and can be set with the choice of the H and L values in –1 dBm steps. 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 DTMF off time (DTFT) respectively as a hexadecimal value with

ms units. The default value for both U47 and U48 is 100 ms, and the range of values is 0–1000 ms.

Table 39. Pulse Dial Registers

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 40. DTMF Dial Registers

U46 DTPL DTMF power level 0x09B0

U47 DTNT DTMF on time (ms units). 0x0064

U48 DTFT DTMF off time (ms units). 0x0064