10 rev. 0.6 – Silicon Laboratories SI2493/57/34/15/04 User Manual
Page 10
Si2493/57/34/15/04
Global ISOmodem-EVB
10
Rev. 0.6
Figure 10 shows the actual circuit connection between the Si2493/57/34/15/04 and the Si3000.
Figure 10. Circuit Connection between the Si2493/57/34/15/04 and the Si3000
To use voice mode register U71 and data memory location 0x0059 must be properly configured.
Setting data memory 0x0059 = 0x0001 enables the Si24XX TDMA interface. When U71 is set to the value 0x0011
a 16-bit voice sample will be transmitted from the Si3000 through the Si2493/57/34/15/04 and DAA to the remote
device. Likewise, an analog signal from the remote device will pass through the DAA where it is converted to a 16-
bit voice sample, the Si24XX and finally the Si3000 where it is converted back to the analog receive signal.
In this example, the Si3000 has its digital TDMA interface configured as the Slave Serial Mode by adding a 50 k
Ω
pull-down resistor to SDO pin and a pull-up 50 k
Ω resistor to SCLK pin. In this mode, the Si3000’s MCLK is driven
by the 2048 kHz clock from Si2493/57/34/15/04. The FSYNC has an 8 kHz pulse input. The bit clock is 2048/
8 = 256 bits per frame sync. Refer to the Si3000 documentation for further details.
To send control information to the Si3000, the Si2493/57/34/15/04 modem chip provides a PCM control port
0x004B that allows the user to send control words across by using the AT memory write command. See Table 4. for
details. Wait for the “OK” (approximately 300 ms after each command). When a connection is established, the “AT.”
command is used to generate the DTMF tone of a number; For example, AT.3<CR> will generate a number 3
DTMF tone without the need for an external DTMF generator. See “Voice Mode Example” for details.
T X D
ESC
RXD
I N T b
CTSb
AOUT
RTSb
RIb
DCDb
SPKR_R
MIC_BIAS
HDST
XTALI
X T A L O
C1A
C1B
SPKR_L
LINEO
LINEI
M I C _IN
R E S E T b
VDD
VDD
VDD
N O T E : D6 (PIN 4) MUST NOT HAVE PULLDOWN RESISTOR
C52
U3
Si2493/57/34/15/04
CLKIN/XTALI
1
X T A L O
2
CLKOUT/EECS/A0
3
D6
4
VD3.3
5
GND
6
VDA
7
RTS/D7
8
VDB
19
GND
20
VD 3.3
21
C2A
13
C1A
14
ESC/D3
22
DCD/D4
23
EECLK/D5
24
CTS/CS
11
RXD/RD
9
TXD/WR
10
R E S E T
12
RI/D1
17
EESD/D2
18
AOUT/INT
15
INT/D0
16
Si3000
MCLK
7
SCLK
8
FSYNC
6
SDI
4
SDO
5
R E S E T
9
LINEI
11
MIC_BIAS
2
MIC_IN
10
LINEO
15
SPKR_L
16
SPKR_R
1
HDST
3
VD
12
V A
13
GND
14
R61
0
C51
C53
R62
47 k
C66
0.1 uF
C50
R63
47 k
C68
0 . 1 uF