Silicon Laboratories SI2493/57/34/15/04 - Manual (Page 30)

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30 Rev. 1.3
2.5. SSI/Voice Mode (24-Pin TSSOP and 38-Pin QFN Only)
Voice mode is supported in the Si2439 and the Si2494. Table 25 lists the pin connections for the ISOmodem SSI
interface. This interface enables Voice Mode operation. See "7. Handset, TAM, and Speakerphone Operation" on
page 173 for additional information.
The Si3000 is used in conjunction with the ISOmodem to transmit and receive 16-bit voice samples to and from
telephone lines as shown in Figure 10.
Figure 10. Voice Mode Block Diagram
Table 25. SSI Interface Pin Connection
Signal Pin Number
(TSSOP-24)
Pin Number
(QFN-38)
CLKOUT 3 3
FSYNC 4 2
SDI 18 8
SDO 24 9
RESET 12 16
Si24xx Modem
Si3000 Voice Codec
Si30xx
DAA
Handset
HOST
AT commands
Responses
2- wire
SDI SDO FSYNC MCLK
CLKOUT SDI SDO
FSYNC
TDMA Interface