RCV56HCF PCI/CardBus Modem Designer’s Guide
Table 3-4. MDP Signal Definitions (Cont'd)
Label | I/O Type | Signal Name/Description |
| TELEPHONE LINE/TELEPHONE/AUDIO INTERFACE SIGNALS AND REFERENCE VOLTAGE | |
TXA1_L1 | O(DF) | Transmit Analog 1 and 2. The TXA1_L1 and TXA2_L1 outputs are differential outputs 180 degrees out of |
TXA2_L1 |
| phase with each other. Each output can drive a 300 Ω load. |
RXA_L1 | I(DA) | Receive Analog. RXA_L1 is a |
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| external hybrid circuit. The input impedance is > 70k Ω. |
TELOUT_L1 | O(DF) | Telephone Handset Analog Output. TELOUT_L1 is a |
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| speaker interface circuit. TELOUT_L1 can drive a 300 Ω load. |
TELIN_L1 | I(DA) | Telephone Handset Analog Input. TELIN_L1 is a |
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| microphone interface circuit. The input impedance is > 70k Ω. |
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MIC_M | I(DA) | Modem Microphone Input. MIC_M is a |
MIC_V | I(DA) | Voice Microphone Input. MIC_V is a |
SPKROUT_M | O(DF) | Modem Speaker Analog Output. The SPKROUT_M analog output reflects the received analog input signal. |
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| The SPKROUT_M on/off and three levels of attenuation are controlled by bits in DSP RAM. When the speaker |
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| is turned off, the SPKROUT_M output is clamped to the voltage at the VC_L1 pin. The SPKROUT_M output |
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| can drive an impedance as low as 300 ohms. In a typical application, the SPKROUT_M output is an input to |
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| an external LM386 audio power amplifier. |
VREF | REF | High Voltage Reference. Connect to VC_L1 through 10 µF (polarized, + terminal to VREF) and 0.1 µF |
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| (ceramic) in parallel. |
VC_L1 | REF | Low Voltage Reference. Connect to analog ground through 10 µF (polarized, + terminal to VC_L1) and |
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| 0.1 µF (ceramic) in parallel. |
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PLLVDD | PLL | PLLVDD Connection. Connect to VAA and to AGND through 0.1 μF. |
PLLGND | PLL | PLLGND Connection. Connect to AGND. |
MK4, MK5 | IA | PLL Circuit Strap Option. Connect MK4 to digital ground and leave MK5 open in order to enable the internal |
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| PLL circuit. |
SPKMD | OA | Modem Speaker Digital Output. The SPKMD digital output reflects the received analog input signal digitized |
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| to TTL high or low level by an internal comparator to create a PC Card |
ROCKWELL PROPRIETARY INFORMATION | 1129 |