mc68194 ON Semiconductor, mc68194 Datasheet
mc68194
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mc68194 Summary of contents
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... MC68194 Carrier Band Modem (CBM) The bipolar LSI MC68194 Carrier Band Modem (CBM) when combined with the MC68824 Token Bus Controller provides an IEEE 802.4 single channel, phase−coherent carrier band Local Area Network (LAN) connection. The CBM performs the Physical Layer function including symbol encoding/decoding, signal transmission and reception, and physical management ...
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SECTION 1 — GENERAL DESCRIPTION 1.1 TOKEN BUS LAN CARRIER BAND NODE OVERVIEW 1.2 CARRIER BAND MODULATION TECHNIQUE 1.3 MESSAGE (FRAME) FORMAT 1.4 SYSTEM CONFIGURATION SECTION 2 — SIGNAL DESCRIPTION TABLE SECTION 3 — TRANSMITTER 3.1 OVERVIEW . . . ...
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... TOKEN BUS LAN CARRIER BAND NODE OVERVIEW The MC68194 Carrier Band Modem (CBM) is part of ON Semiconductor’s solution for an IEEE 802.4 token bus carrier band Local Area Network (LAN) node. The CBM integrates the function of the phase−coherent Frequency Shift Keying (FSK) physical layer. Figure 1− ...
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Mac−Symbol Silence {off off} Pad−Idle Pairs { Zero {H H} One {L L} Non−Data ND1 {H L} ND2 {L H} Figure 1−3. MAC Symbol Encoding ONE ND1 1 BIT TIME = 1/ BIT RATE ...
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DTE−DCE interface. Management and transmission symbol requests are accepted via the CBM physical data request channel (TXSYM0−TXSYM2, SMREQ*, and TXCLK). The physical data indication channel (RXSYM0−RXSYM2, SMIND*, and RXCLK) is used to send received symbols and management responses ...
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... SYNCHRONIZE VCM− VCX PLL FILTER Figure 1−5. Functional Block Diagram data links, fiberoptic modems, and proprietary LANs. The MC68194 can be used over a wide range of frequencies and interfaces easily into different kinds of media. http://onsemi.com 6 AMPLIFICATION AND WAVESHAPING F−CONNECTOR TXOUT ...
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Symbol Type TXSYM0−TXSYM2 TTL/I* SMREQ* TTL/I* TXCLK TTL/O RXSYM0−RXSYM2 TTL/O SMIND* TTL/O RXCLK TTL/O EOTDIS* TTL/I* TXOUT,TXOUT* ECL/O TXDIS OC JAB TTL/O RESET TTL/I* *All TTL inputs include a 15 kΩ pullup resistor to V SECTION 2 SIGNAL DESCRIPTION Name/Description ...
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Symbol Type RXIN, RXIN* I FDBK, FDBK* THRESHOLD I GAIN O CARDET O RPW, CPW I SET−PW O UP*, DOWN* ECL/O VCX I VCM−C1, VCM−C2 I JAB−RC I XTAL,1 XTAL2 I V −VCM CC V −TXOUT CC V −OSC CC ...
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... TX symbols and generate the modulated signal. 3.2 TRANSMIT BUFFER The modulated transmit data stream drives the TXOUT and TXOUT* pins of the MC68194. These pins are complementary outputs with closely matched edge transitions. This is useful in helping meet the IEEE 802.4 carrierband requirement for a transmit jitter of less than " ...
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... LOOPBACK commands can then be used to re−enable the transmitter outputs. While the PHYSICAL ERROR indication is present, the normally−low JAB pin of the MC68194 will be high. This TTL output may be used to turn off external transmitter circuitry or an isolation relay. A block diagram of the jabber inhibit function is shown in Figure 3− ...
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For crystal load C1C2/(C1 + C2) and [C1/(C1 − 20 pF)] Typical values are and pF suggested that best results will ...
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... The MC68194 requires a pre−amplifier of about front of the onboard amplifier and carrier detect function. Clock and data recovery are extracted from the ...
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OVERVIEW The clock recovery circuitry is a key part of the receive function providing RX clock times (2X) RX clock, and a 4 times (4X) RX clock for data recovery and to send receive symbols to the ...
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Figure 5−3 shows the arrangement of the external timing capacitor and resistor. The internal resistor R used with or without an external resistor. A test pin is also provided (SET−PW) to monitor the pulse width. For 5 Mbps operation, typically ...
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... The RXOUT signal from the receive amplifier and clocks generated by the clock recovery logic are used by the data recovery logic. The MC68194 recovers the data from the encoded receive signal by opening sampling windows around the 1/4 and 3/4 bit time positions and looking for edges in the received signal (refer to Figure 6− ...
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... MAC−symbol times but not more than 32 MAC−symbol times from the last MAC−symbol of the End Delimiter. The MC68194 provides this function by recognizing the last End Delimiter of a transmission (I Bit = 0, see Section 1.3). The CBM reports silence for 32 symbols after the last symbol of the End Delimiter ...
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OVERVIEW The serial interface is composed of the Physical Data Request Channel and the Physical Data Indication Channel. The serial interface is used to pass commands and data frames to and from the CBM. 7.2 PHYSICAL DATA REQUEST CHANNEL ...
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... The transmitter must be activated with the ENABLE TRANSMITTER command. The MC68194 responds to this command with the ACK management response. 3. The MC68194 must exit the management mode and enter the MAC data mode. The CBM is now ready to send and receive data, i.e., the CBM is in MAC or data mode, loopback is disabled, and the transmitter is enabled ...
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... PLL must have sufficient time to lock to the new clock source (TXCLK) before being required to provide a response. To provide enough time for the PLL to lock up, the MC68194 delays 16 clock periods before entering station management mode (SMIND after the station management mode is selected (SMREQ* = 0). Refer to Figure 8− ...
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TXCLK TXSYMx VALID COM- MAND RXCLK (1) IN PHASE RESPONSE (1) RXSYMx RXCLK (2) OUT OF PHASE RESPONSE (2) RXSYMx Figure 8−1. Parallel Command Response Time TXCLK TXSYMx RXCLK (1) IN PHASE RESPONSE (1) VALID SMDATA RESPONSE RXSYMx START BIT ...
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... RECEIVER (SINGLE−ENDED OPERATION) GAIN Output Voltage HIGH GAIN Output Voltage LOW Input Signal (for limiting) Detected Threshold PHASE DETECTOR OUTPUTS (UP*, DOWN*) Phase Detector Output Voltage HIGH Phase Detector Output Voltage LOW SECTION 9 MC68194 CARRIER BAND MODEM ELECTRICAL SPECIFICATIONS Symbol OUT ...
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DC ELECTRICAL CHARACTERISTICS (cont.)− POWER SUPPLY DRAIN CURRENT Characteristic Power Supply Drain Current VCM VCM Oscillator Frequency VCM Tuning Ratio VCX Tuning Range ONE−SHOT SET−PW Output Voltage HIGH SET−PW Output Voltage LOW Timing Current Internal Resistor Timing Reference Voltage (measured ...
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RXSYM0−RXSYM2, 1.5 V SMREQ* t setup TXCLK (A) TXSYMX, SMREQ* Setup and Hold Timing to TXCLK RXSYM0−RXSYM2, SMIND* RXCLK 1.5 V (B) RXSYMX, SMIND* Delay Timing to RXCLK 2.5 V XTAL1, XTAL2 t TXCLK delay 1.5 V TXCLK (C) TXCLK ...
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CAP pF Figure 9−3. One Shot Pulse Width versus Rext/Cext 1000 100 100 CAPACITANCE (pF) Figure 9−5. VCM Frequency versus Capacitance 800 600 400 200 0 Figure 9−7. ...
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... B 0.785 0.795 19.94 20.19 C 0.165 0.200 4.20 5.08 D 0.017 0.021 0.44 0.53 F 0.026 0.032 0.67 0.81 G 0.050 BSC 1.27 BSC H 0.090 0.130 2.29 3.30 J 0.006 0.010 0.16 0.25 K 0.035 0.045 0.89 1.14 N 0.735 0.756 18.67 19.20 R 0.735 0.756 18.67 19.20 S 0.690 0.730 17.53 18.54 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative MC68194/D ...