Semiconductor
OPERATION MODE
MOD2
0
0
1
1
MOD1
0
1
0
1
Table 1 Operation Mode
Mode
FSK Modem Normal Mode (Fig.2)
Analog Loop Back Test Mode (Fig.3)
Answer Tone Transmit/Detect Mode*
Power Down Mode
* Answer Tone Transmit: RS = "0"
Æ Enable
RS = "1"
Æ Disable
Answer Tone Detect: Detect
Æ CD = "0"
Non-detect Æ CD = "1"
When transmitting the answer tone, CD is held at digital "1".
MSM7510
AI
Phone
Line
AO
Receive Filter
Transmit Filter
Demodulator
Modulator
Figure 2 FSK Modem Normal Mode
RD
DTE
XD
AI
Phone
Line
AO
SG
Receive Filter
Transmit Filter
Demodulator
Modulator
Figure 3 Analog Loop Back Test Mode
RD
DTE
XD
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