Datasheet

TLV320AIC1110

SLAS359 – DECEMBER 2001

www.ti.com

PRINCIPLES OF OPERATION

receive operation (continued)

Table 6. Receive-Data Bit Definitions

BIT NO. COMPANDED

MODE

LINEAR

MODE

1 CD7 LD14

2 CD6 LD13

3 CD5 LD12

4 CD4 LD11

5 CD3 LD10

6 CD2 LD9

7 CD1 LD8

8 CD0 LD7

9 – LD6

10 – LD5

11 – LD4

12 – LD3

13 – LD2

14 – LD1

15 – LD0

16 – ––

Transmit channel gain control bits always follow the PCM data in time:

CD7-CD0 = data word in companded mode

LD14-LD0 = data word in linear mode

DTMF generator operation and interface

The DTMF circuit generates the summed DTMF tones for push button dialing and provides the PDM output for

the BUZZCON user-alert tone. The integer value is determined by the formula round tone [Freq (Hz)/resolution

(Hz)]. The integer value is loaded into one of two 8-bit registers, high-tone register (04) or low-tone register (05).

The tone output is 2 dB higher when applied to the high-tone register (04). When generating DTMF tones, the

high-frequency value must be applied to the high tone register (04) and the low DTMF value to the low-tone

The DTMF frequency resolution is controlled by the auxiliary register (06) bits 2, 3, 4, and 5. When the resolution

is set to 7.8125 Hz, the frequency range can be up to 1992.2 Hz. A wider range can be accomplished (for

example, 2x or 4x) by selecting lower resolutions of 15.625 Hz or 31.250 Hz. The gain setting is controlled by

the RXPGA gain control. This register applies the required gain to obtain MUX control during tone mode

operation. Table 3 shows the relationship of the two gain settings.