MX805A COMMUNICATION SEMICONDUCTORS Sub-Audio Signaling Processor DATA BULLETIN Features • • • • • • • Non-predictive CTCSS Tone Decoder DCS Sub-Audio Signal demodulator CTCSS /NRZ Encoder with TX level adjustment and lowpass filter output stage with optional NRZ pre-emphasis RX LPF RX SUB-AUDIO OUT COMPARATOR OUT IN RX SUB-AUDIO IN + DIGITAL NOISE FILTER _ 180Hz/260Hz Selectable Sub-Audio bandstop filter NoTone (CTCSS RX) period timer Low Power Operation Member of DBS800 Family (C-BUS Compatible) FREQUENCY ASSESMENT NOTONE NOTONE TIMER COMPARATOR AMP AMP OUT COMMAND DATA RAW NRZ DATA REPLY DATA NRZ RX DATA AND BAUD RATE EXTRACTOR + AMP IN _ RX AMP NRZ RX BAUD RATE NRZ RX DATA VDD FREQUENCY MEASUREMENT CLOCK GENERATOR DATA BUFFER AND SHIFT REGISTER SERIAL CLOCK WAKE ADDRESS SELECT NRZ TX DATA VARIABLE BANDWIDTH CTCSS SUBAUDIO FREQUENCY XTAL VSS INTERRUPT AND TX XTAL/ CLOCK CHIP SELECT CONTROL LOGIC RX VBIAS C-BUS INTERFACE TX SUB-AUDIO OUT TX LEVEL ADJUST SUB-AUDIO BANDSTOP TX SUB-AUDIO LPF AUDIO IN AUDIO OUT AUDIO SIGNAL PATH AUDIO BYPASS The MX805A is a sub-audio frequency signaling processor that provides outband audio and digital signaling capability for LMR systems. Designed for the transmission and non-predictive reception of Continuous Tone Controlled Squelch (CTCSS) tones and other non-standard frequencies, the MX805A also handles NonTM Return-to Zero (NRZ) data reception and transmission to provide Digitally Coded Squelch (DCS/DPL ) and TM LTR signaling. Setting the MX805A functions and modes is accomplished by data loaded from the microcontroller to the controlling registers within the device. Reply Data and Interrupt protocol keep the microcontroller up to date on the operational status of the circuitry. CTCSS tone data for transmission is generated in the microcontroller, loaded to the CTCSS TX Frequency Register, encoded and output as a tone via the TX Subaudio LPF. Received non-predicted CTCSS tone frequencies are measured and the resulting data, in the form of a 2-byte data word, is presented to the microcontroller for matching against a lookup table. Noise filtering is provided to improve the signal quality prior to measurement. NRZ coded data streams for transmission, when generated within a microcontroller, are loaded to the NRZ TX Data Buffer and output, in 8-bit bytes, through the lowpass filter circuitry as subaudible signals. DCS turnoff tones can be added to the data signals by switching the MX805A to the CTCSS transmit mode at the appropriate time. NRZ coding is produced by the microcontroller and translated to subaudio signals by the MX805A. Received NRZ data is filtered, detected, and placed into the NRZ Data Register, which is then available for transfer (one byte at a time) to the microcontroller for decoding by software. Clock extraction circuitry is provided on-chip. TX ad RX baud rates are selectable. Hardware and software are designed to allow consecutive addressing of two MX805A Sub-Audio Signaling Processors to achieve multi-mode duplex operation. Powersaving may be controlled by software or by an input dedicated to the purpose. The MX805A may be used with a 5.0V power supply and is available in the following packages: 24-pin SOIC (MX805ADW), 24-pin PLCC (MX805ALH), and 24-pin PDIP (MX805AP). ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor Page 2 of 24 MX805A Contents Section Page 1 Block Diagram ............................................................................................................... 4 2 Signal List ...................................................................................................................... 5 3 External Components ................................................................................................... 7 3.1 Input configurations............................................................................................................ 8 3.1.1 Using and External Op-Amp...................................................................................................... 8 4 General Description ...................................................................................................... 9 4.1 4.2 Glossary ............................................................................................................................ 9 Operating Modes ............................................................................................................... 9 4.2.1 NRZ Encoding ........................................................................................................................... 9 4.2.2 CTCSS Encoding ...................................................................................................................... 9 4.2.3 NRZ Decoding ......................................................................................................................... 10 4.2.4 CTCSS Decoding .................................................................................................................... 10 5 Controlling Protocol ................................................................................................... 10 5.1 5.2 MX805A Internal Registers .............................................................................................. 10 5.1.1 Control Register (70H/78H)..................................................................................................... 10 5.1.2 Status Register (71H/79H) ...................................................................................................... 10 5.1.3 CTCSS Rx Frequency Register (72H/7AH) ............................................................................ 10 5.1.4 CTCSS Tx Frequency/NRZ Tx or Rx Baud Rate Register (73H/7BH) ................................... 10 5.1.5 NRZ Rx Data Register (74H/7CH) .......................................................................................... 10 5.1.6 NRZ Tx Data Register (75H/7DH)........................................................................................... 10 5.1.7 Gain Set Register (76H/7EH) .................................................................................................. 10 Address/Commands ........................................................................................................ 11 5.2.1 Write to Control Register - A/C 70H (78H) followed by 1 byte of Command Data.................. 12 5.2.2 General Reset ......................................................................................................................... 12 5.2.3 Read Status Register –A/C 71H (79H) followed by 1 byte of Rely Data. ............................... 13 5.2.4 Read CTCSS RX Frequency Register –A/C 72H (7AH) followed by 2 bytes of Reply Data .. 13 5.2.5 Write to CTCSS TX Frequency/NRZ Baud Data Rate Register –A/C 73H (7BH) followed by 2 bytes of Command Data.................................................................................................. 15 5.2.6 Read NRZ RX Data Register – A/C 74H (7CH) followed by 1 byte Reply Data ..................... 17 5.2.7 Write to NRZ TX Data Register – A/C 75H (7DH) followed by 1 byte of Command Data. ..... 17 5.2.8 Write to Gain Set Register – A/C 76H (7EH) followed by 1 byte of Command Data .............. 17 ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor Page 3 of 24 MX805A 6 Performance Specifications ....................................................................................... 18 6.1 Electrical Specifications ................................................................................................... 18 6.1.1 Absolute Maximum Limits .............................................................................................................. 18 6.1.2 Operating Limits............................................................................................................................. 18 6.1.3 Operating Characteristics .............................................................................................................. 19 6.1.4 Timing ............................................................................................................................................ 22 6.2 Packages......................................................................................................................... 23 MXCOM, Inc. reserves the right to change specifications at any time without notice. ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor Page 4 of 24 MX805A 1 Block Diagram RX LPF RX SUB-AUDIO OUT COMPARATOR OUT IN RX SUB-AUDIO IN + DIGITAL NOISE FILTER _ 180Hz/260Hz FREQUENCY ASSESMENT NOTONE NOTONE TIMER COMPARATOR AMP AMP OUT COMMAND DATA RAW NRZ DATA REPLY DATA NRZ RX DATA AND BAUD RATE EXTRACTOR + AMP IN _ RX AMP NRZ RX BAUD RATE NRZ RX DATA VDD FREQUENCY MEASUREMENT CHIP SELECT INTERRUPT AND SERIAL CLOCK CONTROL LOGIC RX VBIAS C-BUS INTERFACE WAKE TX XTAL/ CLOCK DATA BUFFER AND SHIFT REGISTER CLOCK GENERATOR ADDRESS SELECT NRZ TX DATA VARIABLE BANDWIDTH CTCSS SUBAUDIO FREQUENCY XTAL VSS TX SUB-AUDIO OUT TX LEVEL ADJUST SUB-AUDIO BANDSTOP TX SUB-AUDIO LPF AUDIO IN AUDIO OUT AUDIO SIGNAL PATH AUDIO BYPASS Figure 1: Block Diagram ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor Page 5 of 24 MX805A 2 Signal List Pin Signal Description The output from the on-chip clock oscillator inverter. External components are required at this input when a Xtal input is used. See Figure 2. The input to the clock oscillator inverter. A Xtal or externally derived clock should be connected here. This input enables two MX805A’s to be used on the same C-BUS to provide dullduplex operation. See Table 4 and Table 5. 1 Xtal 2 Xtal/Clock 3 Address Select 4 IRQ 5 Serial Clock 6 Command Data 7 CS Chip Select . This is the ‘C-BUS’ data loading control function. This input is provided by the microcontroller. Data transfer sequences are initiated, completed or aborted by the CS signal. See Timing diagrams. 8 Reply Data 9 TX Sub-Audio Out 10 Audio In 11 Audio Out 12 VSS 13 RX Amp In (-) 14 RX Amp In (+) 15 RX Amp Out 16 RX Sub-Audio In 17 RX Sub-Audio Out 18 VBIAS 19 Comparator In (-) 20 Comparator In (+) This is the ‘C-BUS’ serial data output to the microcontroller. The transmission of Reply Data bytes is synchronized to the Serial Clock under the control of the CS input. This 3-state output is held at high impedance when not sending data to the microcontroller. See Timing Diagrams This is the subaudio output (pure or NRZ derived). Signals are band limited. The TX Output Filter had a variable bandwidth (See Table 9). This output is at VBIAS (a) when the NRZ Encoder is enabled but no data is being transmitted, (b) when the MX805A is placed in the Powersave All condition. This is the input to the switched sub-audio bandstop (highpass) filter. It is internally biased, and should be AC coupled by capacitor C7. This is the output of the audio signal path (filter or bandpass). It is controlled by the Control Register. When disabled, the pin is held at VBIAS. Negative Supply (GND) This is the inverting input to the on-chip RX Input Amp. (See Figure 2, Figure 3, and Figure 4). This is the non-inverting input to the on-chip RX Input Amp. This is the output of the on-chip RX Input Op-Amp. This circuit may be used, with external components, as a signal amplifier and anti-aliasing filter prior to the RX Lowpass Filter, or for other purposes. See Figure 2 for Component details. This is the received Sub-Audio (CTCSS/NRZ) input. It is internally referenced to VBIAS. This signal to this pin should be AC coupled or biased. See Figure 2. This is the output of the RX lowpass filter. It may be coupled into the on-chip amplifier or comparator as required. The internal circuitry bias line, held at VDD/2. This pin must be decoupled to VSS by capacitor C8. See Figure 2. This is the inverting input to the on-chip ‘comparator’ amplifier. See Figure 2, Figure 3, and Figure 4. This is the non-inverting input to the on-chip ‘comparator’ amplifier. See Figure 2, Figure 3, and Figure 4. ã2001 MX-COM, Inc. Interrupt Request . The output of this pin indicates an interrupt condition to the microcontroller by going to a logic ‘0”. This ‘wire-or-able’ output allows the connection of up to 8 peripherals to 1 interrupt port on the microcontroller. This pin has a low impedance pulldown to logic ‘0’ when active, and a high impedance when inactive. The system IRQ line requires 1 pull-up resistor to VDD. The conditions that cause interrupts are indicated in the Table 5 and Table 7. This is the ‘C-BUS’ serial Clock input. This clock, produced by the microcontroller, is used for transfer timing of commands and data to and from the MX805A. See timing diagrams. This is the ‘C-BUS’ serial data input from the microcontroller. Data is loaded to this device in 8-bit bytes, MSB (bit 7) first and LSB (bit 0) last, synchronized to the Serial Clock. See Timing diagrams. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor Pin Page 6 of 24 Signal 21 Comparator Out 22 Notone Timing 23 Wake MX805A Description This is the output of the ‘comparator’ amplifier. This node is also connected internally to the input of the /digital Noise Filter (See Figure 1). When both decoders (CTCSS or NRZ) are powersaved, this output is at a logic ‘0’. External RC components connected to this pin form the timing mechanism of a Notone period timer. The external network determines the “charge rate” of the timer to VBIAS. The expiration of the timer will cause an interrupt. This function is only used in the CTCSS RX mode. See page 9. This ‘real time’ input can be used to reactivate the MX805A from the ‘Powersave All’ condition using an externally derived signal. The MX805A will be in ‘Powersave All’ condition when both this pin and bit 0 of the Control Register are set to a logic ‘1’. Recovery from ‘Powersave All’ is achieved by putting either the Wake pin or the ‘Powersave All” bit at logic ‘0’. This allows MX805A activation by the microcontroller or an external signal, such as RSSI or Carrier Detect. 24 VDD Positive Supply. A single 5.0V regulated supply is required. Note: More information on external components and the DBS800 system integration of the MX805A are contained in the DBS800 System Support Documentation. Guidance on the generation and manipulation of NRZ and RX and TX data is given in the DBS800 Application support documentation. C-BUS: This is MX-COM’s proprietary standard for the transmission of commands and data between a microcontroller and DBS8000 microcircuits. It may be used with any microcontroller, and can, if desired, take advantage of the hardware and serial I/O functions embodied into many types of microcontroller. The C-BUS data rate is determined by the microcontroller. Table 1: Signal List RX CTCSS Tone Measurement Completed CTCSS NOTONE Timer Expired 1 NRZ RX Data Byte Received New NRZ Data Received Before Last Byte Read NRZ TX Buffer Ready NRZ Data Transmission Complete Table 2: Interrupt Conditions ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor Page 7 of 24 MX805A 3 External Components VDD + R7 SEE INSET XTAL XTAL/CLOCK ADDRESS SELECT IRQ SERIAL CLOCK COMMAND DATA CS REPLY DATA R8 TX SUB-AUDIO OUT C7 AUDIO IN AUDIO OUT VSS 1 2 3 4 5 6 7 8 9 10 11 12 MX805AJ 24 23 22 21 20 19 18 17 16 15 14 13 C5 R6 V DD WAKE C6 NOTONE + COMPARATOR OUT R4 C8 COMPARATOR IN (+) COMPARATOR IN (-) VBIAS RX SUB-AUDIO OUT C3 RX SUB-AUDIO IN R3 D1 D2 RX AMP OUT RX AMP IN (+) RX AMP IN (-) R2 + R5 C4 INSET XTAL 1 X1 MX805AJ R1 XTAL/CLOCK C2 2 C1 Figure 2: Recommended External Components Component Notes Value Tolerance Component Value Tolerance R1 5 1.0MΩ ±5% C3 1.5µF ±20% R2 4 360kΩ ±5% C4 15.0µF, 6V Tant. ±20% R3 1 10.0kΩ ±5% C5 1.0µF, 10V Tant. ±20% R4 4 150kΩ ±5% C6 1.0µF, 10V Tant. ±20% R5 4 100kΩ ±5% C7 0.1µF, 25V x 7R ±20% 150kΩ ±5% C8 1.0µF R6 R7 6 22.0kΩ ±5% R8 2 360kΩ ±5% C1 C2 5 5 Notes D1 8 D2 X1 8 4.00MHz Table 3: Recommended External Components ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor Page 8 of 24 MX805A Recommended External Component Notes: 1. Xtal/Clock circuitry shown in inset are recommended in accordance with the MX-COM’s “Standard and DBS 800 Crystal Oscillators” application note. 2. Resistor R8 is a System Component. Its value is chosen together with the MX806A Modulation Summing Amplifier to provide a subaudio signal level of –11.0dB to the system modulator. 3. Figure 3 and Figure 4 illustrate alternative input component configurations. 4. The values for R2 and R5 are dependent on the input signal level. Values given are for the specified composite signal (reference page 14). R4 add hysteresis to the comparator and is not always required. 5. The values used for C1 and C2 are determined by the frequency of X1. C1 = C2 = 33pF for X1 < 5.0MHz As a guide: C1 = C2 = 18pF for X1 > 5.0MHz If the on-chip Xtal oscillator is to be used, then the external components X1, C1, C2, and R1 are required as shown in Figure 2 (inset). If an external clock source is used these components are not required; the input should be connected to the Xtal/Clock pin and the Xtal pin unconnected. 6. Resistor R7 is used as the DBS800 system common pull-up for the C-BUS Interrupt Request ( IRQ ) line. The optimum value of this component will depend upon the circuitry connected to the IRQ line. 7. The level at this point should be approximately 900mVP-P. 8. Silicon small signal 3.1 Input Configurations Figure 3 shows an input configuration that is generally for use for CTCSS signal and NRZ data reception. Input coupling capacitor C3 is required because the RX Sub-Audio Input is held at VBIAS during all powered conditions of the MX805A. Diodes D1 and D2 can be any silicon small signal diode. The output resistance (open loop) of the on-chip Rx Amp is = 6kΩ. In the configuration shown in Figure 3, the (Rx Amp) RC time constant is therefore 90ms. If this period is too long for some systems, i.e. those using half duplex, short data burst, and external amplifier should be considered in place of the on-chip Rx Amp. MX805A RX AMP MX805A RX LPF 17 D.C. RESTORATION + 14 MX805A COMPARATOR RX AMP IN 13 16 C3 HYSTERESIS (OPTIONAL) NOTE 7 15 _ R4 R3 D1 D2 R2 20 + COMPARATOR IN RX SUB-AUDIO INPUT 19 R5 21 _ C4 COMPARATOR OUT Figure 3: MX805A Input Components 3.1.1 Using and External Op-Amp For DC coupling the MX805A to the receiver’s discriminator output when using burst mode NRZ communication, it is recommended that an additional, external Op-Amp is employed as configured in Figure 4. This configuration will quickly compensate for sudden shift of DC input bas. Components R9, R10, and R11, should be calculated to provide an accurate potential of 2.5VDC (equal to VBIAS) at pin junction 15/16when using a discriminator input and 900mVP-P at the output of the external opamp. Note that the MX805A LPF has a 6dB gain. If additional filtering is required, C9 should be used, it should be calculated with R9 to provide a lowpass cutoff frequency (fCO) of 500Hz. ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor Page 9 of 24 MX805A RX LPF Gain = 6dB FROM RX DISCRIMINATOR MX805A RX AMP + 14 MX805A 16 RX AMP IN 15 17 + EXTERNAL OP-AMP NOTE 6 (see p.4) _ 13 _ MX805A COMPARATOR R3 C9 D2 270k D1 20 R9 19 100k VDD + COMPARATOR IN 21 _ 15 mF COMPARATOR OUT R11 R10 D.C. RESTORATION LEVEL SHIFT AND AMPLIFY Figure 4: MX805A Input Components using and External Op-Amp 4 General Description 4.1 Glossary DCS CTCSS TM DPL TM LTR NRZ fCO fCTCSS IN fCTCSS OUT fTONE fXTAL RNRZRX RNRZTX sINPUT 4.2 4.2.1 Continuous Digitally Coded Squelch Continuous Tone Controlled Sub-Audio Squelch Digital Private Line Logic Trunked Radio Non-Return-to-Zero Filter Cutoff frequency Sub-Audio Rx frequency Sub-Audio Tx frequency Tone frequency Xtal/Clock frequency NRZ RX baud rate NRZ TX baud rate Audio input signal. Operating Modes NRZ Encoding The NRZ Encoder is formed by a shift register and the TX Sub-Audio Lowpass Filter. Data loaded from the Command Data line is output one 8-bit byte at a time from the NRZ Tx Data Register. The output data level may be adjusted and filtered. Data may be pre-emphasized via a C-BUS command. The expected Rx baud rate is programmed as the NRZ Tx Baud Rate (RNRZTX). See Table 8 4.2.2 CTCSS Encoding The CTCSS Tone Encoder is comprised of a clock divider programmed by an 11-bit binary number (Q) loaded to the CTCSS Tx Frequency Register (See Table 8) via the C-BUS Command Data line. The square-wave output of the encoder is fed through the Tx Level Adjust variable gain block to the Tx Sub-Audio lowpass filter, a variable gain bandwidth circuit controlled by 4-bits (P) if the CTCSS Tx Frequency Register. The Tx Sub-Audio output is a sine-wave. Standard and nonstandard sub-audio tones are available. A CDCS turnoff tone may also be generated. ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor 4.2.3 Page 10 of 24 MX805A NRZ Decoding Input (NRZ type) sub-audio signals are filtered and the data clock extracted. Decoded data is serially loaded into a shift register buffer. This data is output on 8-bit byte at a time as Reply Data from the NRZ Rx Data Register to the microcontroller. The expected Rx baud rate is programmed as the NRZ Rx Baud Rate (RNRZRX). See Table 8. Any codeword recognition can be carried out by software. 4.2.4 CTCSS Decoding Received CTCSS signals are filtered, and coherence is increased by the digital noise filter. The quality of the signal is assessed by measurement of the cycle–to-cycle period variance and, provided it is sufficiently good, the frequency is measured over a period of 122.64ms (4.0MHz crystal). If the average signal quality is consistently too low, NoTone is indicated; if not the input frequency is precisely indicated in the CTCSS Rx Frequency Register in a binary form. Any single sub-audio tone within the specified range may be selected, enabling a DCS turnoff tone of 134Hz) to be decoded while in the NRZ Rx mode. 5 Controlling Protocol Control of the MX805A Sub-Audio Signaling Processor’s operation is by communications between the microcontroller and the MX805A internal registers on the C-BUS, using Address/Commands (A/Cs) and appended instructions or data (See Figure 10). The use and content of these instructions is detailed in the following paragraphs and tables. The Address Select Input enables the addressing of 2 separate MX805As on the C-BUS to provide full-duplex signaling. 5.1 5.1.1 MX805A Internal Registers Control Register (70H/78H) Write only, control and configuration of the MX805A. 5.1.2 Status Register (71H/79H) Read only, reporting of device functions. 5.1.3 CTCSS Rx Frequency Register (72H/7AH) Read only, a 2-byte binary word indicating the frequency of the received sub-audio input. 5.1.4 CTCSS Tx Frequency/NRZ Tx or Rx Baud Rate Register (73H/7BH) Write only, a 2-byte command to set the relevant parameters. 5.1.5 NRZ Rx Data Register (74H/7CH) Read only, a single byte f received NRZ data. 5.1.6 NRZ Tx Data Register (75H/7DH) Write only, to load a single byte of NRZ data for transmission. 5.1.7 Gain Set Register (76H/7EH) Write only, a single byte to set the gain of the Tx Lowpass Filter. ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor 5.2 Page 11 of 24 MX805A Address/Commands The first byte of a loaded data sequence is always recognized by the C-BUS as an Address/Command (A/C) byte. Instruction and data transactions to and from this device consist of an Address/Command byte followed by either: (i) further instructions or data (ii) a Status or data Reply Instructions and data are loaded and transferred, via C-BUS, in accordance with the timing information in Figure 9 and Figure 11. Placing the Address Select input at a logic “0” will address MX805A #1, a logic “1” will address MX805A #2. Table 4 and Table 5 show the list of A/C bytes relevant to the MX805A Command Assignment Address/Command (A/C) byte Hex Data Bytes Binary MSB LSB General Reset 01 00000001 Write to Control Register 70 01110000 +1 byte instruction to Control Register Read Status Register 71 01110001 +1 byte reply from Status Register Read CTCSS Rx Freq. Reg. 72 01110010 +2 byte reply of CTCSS Rx Data Write to CTCSS Tx Freq./NRZ Baud Rate Reg. 73 01110011 +2 byte instruction for Tx Frequency and NRZ Tx/Rx baud rates Read NRZ Rx Data Reg. 74 01110100 +1 byte binary data Reply Write to NRZ Tx Data Reg. 75 01110101 +1 byte binary data Command Write to Gain Set Reg. 76 01110110 +1 byte instruction for Tx Output Table 4: MX805A #1 C-BUS Address/Commands – (Address Select input at a logic “0”) Command Assignment Address/Command (A/C) byte Hex Data Bytes Binary MSB LSB General Reset 01 00000001 Write to Control Register 78 01111000 +1 byte instruction to Control Register Read Status Register 79 01111001 +1 byte reply from Status Register Read CTCSS Rx Freq. Reg. 7A 01111010 +2 byte reply of CTCSS Rx Data Write to CTCSS Tx Freq./NRZ Baud Rate Reg. 7B 01111011 +2 byte instruction for Tx Frequency and NRZ Tx/Rx baud rates Read NRZ Rx Data Reg. 7C 01111100 +1 byte binary data Reply Write to NRZ Tx Data Reg. 7D 01111101 +1 byte binary data Command Write to Gain Set Reg. 7E 01111110 +1 byte instruction for Tx Output Table 5: MX805A #2 C-BUS Address/Commands – (Address Select input at a logic “1”) ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor 5.2.1 Page 12 of 24 MX805A Write to Control Register - A/C 70H (78H) followed by 1 byte of Command Data Table 6 shows the configurations available to the MX805A. Bits 5, 6, and 7 are used together to Enable and Powersave circuits sections as required. Setting Control Bits Transmitted First MSB 7 6 5 Enabled Powersaved 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 CTCSS Decoder NRZ Decoder CTCSS Encoder NRZ Encoder CTCSS Encoder and Decoder NRZ Encoder and CTCSS Decoder NRZ Decoder and CTCSS Decoder NRZ Decoder NRZ Decoder and Both Encoders CTCSS Decoder and Both Encoders All Decoders All Decoders NRZ Encoder and Decoder No circuits All Encoders All Encodes except Tx Sub-Audio LPF and CTCSS Decoder 4 1 0 Enable Audio Output – Used with Bit 3 Disable Audio Output – output to VBIAS 3 1 0 Enable Sub-Audio Bandstop Filter (Audio Signal Path) Bypass Sub-Audio Bandstop Filter 2 1 0 Enable All MX805A Interrupts Disable All MX805A Interrupts 1 1 0 Set Rx Lowpass Filter Bandwidth to 180Hz – for low CTCSS tones or NRZ Data Set Rx Lowpass Filter Bandwidth to 260Hz 0 1 0 All encoders and Decoders Powersaved All Encoders and Decoders Enabled unless individually Powersaved Table 6: Control Register 5.2.2 General Reset Upon power-up the bits in the MX805A registers will be random (either 0 or 1). A General Reset Command (01H) will be required to reset all devices on the C-BUS. It has the following effect on the MX805A: Control Register Set to 00H Status Register Set to 00H NoTone Timer Discharged Warning: The following MX805A register configurations are not affected by a General Rest Command: CTCSS Rx Frequency CTCSS Tx Frequency/NRZ Baud Rate Register NRZ Rx Data Register NRZ Tx Data Register Gain Set Register Note: Setting the Control Register in this way will set the MX805A to the CTCSS decode mode and overwrite a “Powersave All” instruction. It should also be considered that a General Reset command will reset All DBS800 ICs operating on the C-BUS. ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor 5.2.3 Page 13 of 24 MX805A Read Status Register –A/C 71H (79H) followed by 1 byte of Rely Data. The Status Register indicates the operational condition of the MX805A. Bits 0 to 5 are set individually to indicate specific actions within the device. When a Status bit is set to a logic “1”, and Interrupt Request (IRQ) output is generated. A read of the Status Register will reset the Interrupt and ascertain the state of this register. Table 7 shows the conditions indicated by the Status bits. Setting MSB 7, 6 Set By Logic Received First Not Used Cleared By Logic 0 Not Used 0 5 NRZ data transmission complete. No new data is loaded. 1 1. Write to NRZ Data Reg., or 2. General Reset, or 3. NRZ Encoder Powersave 0 4 NRZ TX Data Buffer ready for next data byte. 1 1. Write to NRZ TX Data Reg., or 2. General Rest, or 3. NRZ TX Powersave 0 3 New NRZ RX data received before last byte was read. 1 1. Read NRZ RX Data Reg., or 2. General Reset, or 3. NRZ Decoder powersave 0 2 1 byte of NRZ data received 1 1. Read NRZ RX Data Reg., or 2. General Reset, or 3. NRZ Decoder powersave 0 1 NoTone timer period expired 1 1. Read Status Register, or 2. General Rest, or 3. CTCSS Decoder Powersave 0 0 RX Tone Measurement Complete 1 1. Read Status Register, or 2. General Reset, or 3. CTCSS Decoder Powersave 0 Table 7: Status Register 5.2.4 5.2.4.1 Read CTCSS RX Frequency Register –A/C 72H (7AH) followed by 2 bytes of Reply Data Measurement of CTCSS RX Frequency (fCTCSS IN) The input sub-audio signal (fCTCSS IN) is filtered, doubled and measured in the Frequency Counter over the “measurement period” (122.64ms) (4.0MHz Xtal). The measuring function counts the number of complete input cycles occurring within the measurement period and the number of measuring-clock cycles necessary to make up one period. When the measurement period of a successful decode is complete, the RX Tone Measurement bit in the Status Register and the Interrupt bit are set. The CTCSS RX Frequency Register will now indicated the sub-audio signal frequency (fCTCSS IN) in the form of 2 data bytes (1 and 0) as illustrated in Figure 6. Measurement Period Complete Input Cycle Complete Input Cycle Complete Input Cycle Complete Input Cycle FILTERED AND DOUBLED SUB-AUDIO INPUT SIGNAL Complete Input Cycle 2 x f Measuring Clock Cycles CTCSS IN N R Figure 5: Measurement of a CTCSS RX Frequency ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor 5.2.4.1.1 Page 14 of 24 MX805A The Integer (N) –Byte 1 The binary number representing twice the number of complete input sub-audio cycle periods counted during the measurement period of 122.64ms (4.0MHz crystal) 5.2.4.1.2 The Remainder (R) –Byte 0 A binary number representing the remainder part, R, of 2x the Sub-Audio Input Frequency. R = number of specified measuring-clock cycles required to complete the specified measurement period (See N). The clock cycle frequency is 4166.6Hz (4.0MHz crystal) Byte 1 (Reply Data) (MSB) - Transmitted First 15 14 "0" "0" 13 12 11 Byte 0 10 9 8 Integer (N) 7 6 "0" "0" 5 4 3 (Reply Data) (LSB) - Transmitted Last 2 1 0 Remainder (R) CTCSS RX Frequency Register Figure 6: Format of the CTCSS RX Frequency Register 5.2.4.2 CTCSS RX Frequency Register The format of the CTCSS RX Frequency Register is shown in Figure 6. Bits 8 (LSB) to 13 (MSB) are used to represent the Integer (N). From Byte 1, valid values of N = 16 ≤ N ≤ 61 i.e. values of N less than 16 and greater than 61 are not within the specified frequency band. Bits 0 (LSB) to 5 (MSB) are used to represent the Remainder (R). From Byte 0, valid values of R ≤ 31 . This register is not affected by the General Reset command (01H) and may adopt any random configuration at Power-UP. 5.2.4.3 CTCSS RX Frequency Measurement Formulas To assist in the production of “lookup” tables and limit-values in the microcontroller, and to provide guidance upon the determination of N and R from a measured CTCSS frequency, the following formulas show the derivation of the CTCSS RX Frequency (fCTCSS IN) from the measured data bytes (N and R). 5.2.4.3.1 fCTCSS IN In the measurement period of 122.64ms there are N cycles at 2 x fCTCSS IN and R clcok cycles at 4166.6Hz, for any input frequency. f CTCSS IN = N × f XTAL 1920 × (511 - R) é 1920 x 511 xfCTCSS IN ù N = INT ê ú f XTAL ë û é æ N x f XTAL R = INT ê511 - çç êë è 1920 x f CTCSS IN ù ö ÷ + .5 ú ÷ úû ø Calculate N first Example: (fXTAL = 4.00Mhz): fCTCSS IN = 100Hz N = 24 R = 11; fCTCSS IN = 250Hz N = 61 R = 3 5.2.4.4 NoTone Timing The input sub-audio signal is monitored by the Frequency Assessment Circuitry. Before any NoTone action is enabled, the MX805A must have achieved at least one successful “Tone Measurement Complete” action. If there is no signal or the signal is of a consistently poor quality, the NoTone timer will start to charge via the timing components. When the timing period has expired (at VDD/2), an Interrupt and a Status bit (NoTone Timer Expired) are generated. This is a one-shot function which is rest by a “Tone Measurement Complete” interrupt. ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor 5.2.5 Page 15 of 24 MX805A Write to CTCSS TX Frequency/NRZ Baud Data Rate Register –A/C 73H (7BH) followed by 2 bytes of Command Data. The information loaded to this register will set either the: (a) CTCSS TX Tone Frequency fCTCSS OUT (b) NRZ TX Baud Rate RNRZ TX (c) NRZ RX Baud Rate RNRZ RX The chosen mode for this register (a, b, or c) is determined by the MX805A modes enabled by the Control Register, as shown in Table 8. Control Register Bits 7 6 5 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 MX805A Mode Enabled CTCSS TX/NRZ Baud Rate Register Function CTCSS Decode NRZ Decode CTCSS Decode NRZ Encode CTCSS Encode and Decode NRZ Encode & CTCSS Decode NRZ & CTCSS Decode NRZ Decode NRZ RX Baud Rate CTCSS TX Frequency NRZ TX Baud Rate CTCSS TX Frequency NRZ TX Baud Rate NRZ RX Baud Rate NRZ RX Baud Rate Table 8 CTCSS Frequency/NRZ Baud Rate Register Configurations 5.2.5.1 Data Format Data is transmitted to this register as 2 bytes of Command Data in the form illustrated in the diagram below. This register is not affected by the General Rest Command (01H) and may adopt any random configuration at power-up. Byte 1 (Command Data) (MSB) - Loaded First 15 13 14 P 12 11 Byte 0 10 9 8 7 6 "0" 5 4 3 (Command Data) (LSB) - Loaded Last 2 1 0 Q CTCSS TX Frequency/NRZ Baud Rate Register Figure 7: Format of the CTCSS TX Frequency/NRZ Baud Rate Register 5.2.5.2 Command Words P and Q The two words, P and Q, loaded to this register are interpreted as: P= a binary number to set the TX Sub-Audio Lowpass filter bandwidth (applicable to NRX and CTCSS modes). Q= A binary number to set the frequency r baud rate of the selected functon. ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor 5.2.5.2.1 Page 16 of 24 MX805A Command Word P Bits LSB 15 14 13 12 P LPF Bandwidth 0 0 0 0 0 0 1 0 0 1 1 1 1 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 2 3 4 5 6 7 8 300Hz 200Hz 150Hz 120Hz 100Hz 85.7Hz 75Hz Table 9: Valid Values of P Bits 12 to 15 are used to produce the data word “P” as shown in Table 9. The cutoff frequency fC/O (0.5dB point) of the TX Sub-Audio Lowpass filter is calculated as: f C/O = P= f XTAL 32 x 208.33 x P f XTAL 32 × 208.33 × f C/O Table 9 is provided as and example and calculated using a Xtal/Clock (fXTAL) frequency of 4.00MHz. As illustrated, only values of “P” of 2 to 8 are usable 5.2.5.2.2 Command Word Q Bits 0 to 10 (See Figure 7) are used to produce the data word “Q” which sets one of the parameters described below. As you can see, Command Word “Q” could be used to produce a parameter outside that specified in the “Characteristics” section of this data bulletin. Care should be taken not to do this. Examples for limits of “Q” in each operational configuration are included. “Q” = 0 is not valid in the following calculations. Bit 11 is not used and must be set to logic “0”. (a) CTCSS TX Tone Frequency (fCTCSS OUT) f CTCSS OUT f XTAL Hz 32 x " Q" fCTCSS OUT = 67Hz So “Q” = 1866 f XTAL Hz 32 x fCTCSS OUT fCTCSS OUT = 250Hz So “Q” = 500 f XTAL bits/sec 32 x " Q" RNRZ TX = 67bps So “Q” = 1866 f XTAL 32 x R NRZ TZ RNRZ TX = 300bits/sec So “Q” = 417 = so " Q" = “11101001010” “00111110100” (b) NRZ TX Baud Rate (RNRZ TX) R NRZ TZ = so " Q" = “11101001010” “00110100001” (c) NRZ RX Baud Rate (RNRZ RX) R NRZ RX = so " Q" = f XTAL bits/sec 32 x 11 x " Q" RNRZ RX = 100bps So “Q” = 114 f XTAL 352 x R NRZ RX RNRZ RX = 300bits/sec So “Q” = 38 ã2001 MX-COM, Inc. “00001110010” “00000100110” www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor 5.2.6 Page 17 of 24 MX805A Read NRZ RX Data Register – A/C 74H (7CH) followed by 1 byte Reply Data Received NRZ data bits are organized into bytes and made available to the microcontroller via the Reply Data line. As 8 bits are received into this register and interrupt is generated to indicate that a complete byte has th been received. This byte must be read before the arrival of the last (8 ) bit of the next incoming byte. If this in not done, an interrupt to indicate this condition will be generated and the previous RX data is discarded. See Table 7. Word synchronization is not provided. Byte synchronization and any codeword recognition will be performed by the host microcontroller. The RX baud rate is set by writing to the CTCSS TX Frequency/NRZ Baud Rate Register (73H/7BH). The first bit received is the first bit sent to the microcontroller. This register is not affected by the General Reset Command (01H), and may adopt random configuration at Power-Up. 5.2.7 Write to NRZ TX Data Register – A/C 75H (7DH) followed by 1 byte of Command Data. A byte for transmission is loaded from the C-BUS Command Data line with the A/C. The first data bit received via the C-BUS is transmitted first. The transmitter operation is non-inverting. The first data byte loaded after the NRZ Encoder is enabled (Control Register) initiates the transmission sequence and an interrupt will be generated when the NRZ TX Data Buffer is ready for the next data byte. Subsequently, interrupts occur for every 8 bits transmitted. Transmission is terminated, the TX Sub-Audio Output is placed at VBIAS, and a interrupt is generated if the next byte is not loaded within 7 bit periods. See Table 7. This register is not affected by the General Reset Command (01H), and may adopt any random configuration at Power-Up. 5.2.8 5.2.8.1 Write to Gain Set Register – A/C 76H (7EH) followed by 1 byte of Command Data Gain Set Register Settings: The settings of this register control the CTCSS and NRZ signal level that is presented at the TX Sub-Audio Output. Bit 3, when enabled, is used to produce a pre-emphasis effect on the NRZ TX Data by increasing the gain of the data bit before a level change (See Figure 8), by 1.72dB to make that data pulse level slightly more positive (or negative). The signal level will be 1.72dB greater that that set by Bits 0 to 2. If the TX Sub-Audio Output level is set to +2.58dB, the pre-emphasis level will be +4.3dB. The pre-emphasis function will remain enabled until disabled by setting Bit 3 to a logic “0”. If this function remains enabled when using the CTCSS Encoder, the output signal may be adversely affected. Therefore this function should be enabled when in the NRZ Encode mode. This register is not affected by the General Reset Command (01H), and may adopt any random configuration at Power-Up. Setting Gain Setting 7 6 5 4 0 0 0 0 Transmitted Bit 7 First 3 Pre-Emphasis Setting 1 0 1.72dB Gain Enabled 1.72dB Gain Disabled 2 1 0 Tx Level Adjust Gain Setting 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 -2.58dB –1.72dB –0.86dB 0dB +0.86dB +1.72dB +2.58dB Not Used Table 10: Gain Set Register Settings ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor 13 14 MX805A Byte 1 (Command Data) (MSB) - Loaded First 15 Page 18 of 24 12 Byte 0 9 10 11 8 7 6 "0" P 5 4 (Command Data) (LSB) - Loaded Last 1 2 3 0 Q CTCSS TX Frequency/NRZ Baud Rate Register Figure 8: Gain Set with Pre-Emphasisi 6 Performance Specifications 6.1 Electrical Specifications 6.1.1 Absolute Maximum Limits Exceeding these maximum ratings can result in damage to the device. General Notes Supply (VDD-VSS) Voltage on any pin to VSS Current VDD VSS Any other pin P / DW / LH Packages Total allowable Power dissipation at TAMB = 25°C Min. Typ. Max. Units -0.3 -0.3 7.0 VDD + 0.3 V V -30 -30 30 30 mA mA -20 20 mA 800 mW 10 Derating above 25°C Operating Temperature mW/°C above 25°C -40 85 °C Storage Temperature -55 125 °C Table 11: Absolute Maximum Ratings 6.1.2 Operating Limits Correct Operation of the device outside these limits is not implied. Notes Supply (VDD-VSS) Operating Temperature Xtal Frequency Min. Typ. Max. Units 4.5 -40 5.0 5.5 85 V 4.0 °C MHz Table 12: Operating Limits ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor 6.1.3 Page 19 of 24 MX805A Operating Characteristics For the following conditions unless otherwise specified. VDD = 5.0V @ TAMB = 25°C Xtal/Clock Frequency = 4.0MHz, Audio Level 0dB ref. = 308mVRMS @ 1kHz Composite Signal = 308mVRMS @ 1kHz + 75mVRMS Noise + 31mVRMS Sub-Audio signal Noise Bandwidth = 5kHz Band Limited Gaussian Notes Min. Typ. Max. Units 5.0 2.0 7.0 3.0 mA mA 0.9 1.5 mA Static Values Supply Current All Functions Enabled All Functions Disabled Powersave All Analog Impedances RX Sub-Audio Input 350.0 Audio Input 350.0 Audio Bypass Switch On 5 Audio Bypass Switch OFF 5 1500.0 kΩ kΩ 2.0 kΩ 1.0 6.5 MΩ RX Amp Input (+ and -) 1.0 6.5 MΩ Comparator Input (+ and -) 1.0 6.5 MΩ 2.0 kΩ RX Sub-Audio Output TX Sub-Audio Output Encoder Enabled 5 2.0 kΩ Encoder Disabled 5 500.0 kΩ Audio Output Encoder Enabled 5 2.0 kΩ Encoder Disabled 5 500.0 kΩ 6.0 kΩ 600.0 kΩ RX Amp and Comparator Outputs Large Signal Small Signal Dynamic Values Digital Interface Input Logic 1 1 Input Logic 0 Output Logic 1 (IOH = -120mA) 1 2 Output Logic 1 (IOL = -360mA) IOUT Tristate (Logic 1 or 0) 3.5 V 1.5 V V 3 3 0.4 4.0 V Input Capacitance 1 7.5 µA pF Logic Input Current (VIN = 0 to 5.0V) 1 1.0 µA IOX (VOUT = 5.0V) 4 4.0 µA ã2001 MX-COM, Inc. 4.6 www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor Page 20 of 24 Notes MX805A Min. Typ. Max. Overall Performance Units dB kHz CTCSS - Decode Sensitivity (Composite Signal) Response Time (Composite Signal) 100Hz to 257Hz Tone 6 65Hz Tone Tone Measurement Resolution Tone Measurement Accuracy 9 NoTone Response Time (Composite Signal) False tone Interrupts (Noise Input Only) CTCSS Encode Frequency Range Tone Frequency Resolution Tone Amplitude Tolerance -20.0 -26.0 210.0 250.0 ms 210.0 0.2 384.0 ms % % 175.0 20.0 250.0 ms /Hr 257.0 0.2 1.0 Hz % dB 30.0 50.0 5.0 ms ms % -0.5 7 10 0.5 65.0 12 -1.0 Rise Time (to 90%) Fall Time (to 10%) Total Harmonic Distortion NRX – Decode RX Bit Rate Sync Time RX Bit Error Rate 2 -3 1 x 10 11 NRZ – TX TX Bit Rate TX LPF (3dB) Bandwidth dB 67.0 75.0 Sub-Audio TX Output Level CTCSS edge P(ERROR) 300.0 300.0 0 NRZ Amplitude Adjustment Range Adjustment Step Size (7 Steps) Sub-Audio Bandstop Filter Passband Passband Gain (@ 1.0kHz) dB 0.871 -2.58 8 2.58 0.86 297.0 Hz dB 0.5 -45.7 dB dB dB 62.5 kHz 280.0 Hz 6.0 4.0 6.1 dB MHz -1.5 36.0 -50.0 Alias Frequency Receive Lowpass Filter (See Figure 9) Cutoff Frequency (-3dB) Passband Gain Xtal/Clock Frequency (fXTAL) VP-P dB dB 3000.0 0 Passband Ripple (with respect to gain @ 1.0Hz) Stopband Gain < 250Hz Residual Hum and Noise bits/sec Hz Table 13: Operating Characteristics ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor Page 21 of 24 MX805A Operating Characteristics Notes: 1. Device control pins: Serial Clock, Command Data, Wake , and CS . 2. Reply Data Output 3. Reply Data and IRQ outputs 4. Leakage current into the “OFF” IRQ output. 5. See Control Register 6. With input gain components set as recommended in Figure 2. 7. Probability 97% 8. See Gain Set Register. 9. For fCTCSS IN of 65Hz to 100Hz, Response Time tR = (100/fTone) x 250ms. 10. Distributed across the RX Frequency band 11. With 10dB signal-to-noise ratio in a bit-rate bandwidth. 12. At any gain setting of Gain Register. Signal Level (dB) Xtal = 4.0 MHz VDD = 5.0V 10dB/division 0 0 100 200 300 400 500 600 700 800 Frequency (Hz) Figure 9: Typical Frequency Response of RX Lowpass Filter ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor 6.1.4 Page 22 of 24 MX805A Timing Timing Parameters for two-way communications between the µC and the MX805A on the C-BUS are shown in Table 14. C-BUS Timing tCSE Chip Select Low to First Serial Clock Rising Edge Min. 2.0 Typ. Max. Units µs tCHS Last Serial Clock Rising Edge to Chip Select High 4.0 µs tCSOFF Chip Select High 2.0 µs tNXT Command Data Inter-Byte Time 4.0 µs tCK Serial Clock Period 2.0 tCH tCL tCDS tCDH tRDS tRDH tHIZ Decoder or Encoder Clock High Decoder or Encoder Clock Low Command Data Set-Up Time Command Data Hold Time Reply Data Set-Up Time Reply Data Hold Time Chip Select High to Reply Data High – Z 500 500 250 0 250 50.0 µs ns ns ns ns ns ns 2.0 µs Table 14: Timing Information Notes: 1. Command Data is transmitted to the peripheral MSB (bit 7) first, LSB (bit 0) last. Reply Data is read from the MX805A MXB (bit 7) first, LSB (bit 0) last. 2. Data is clocked into the MX805A and into the microcontroller on the rising Serial Clock edge. 3. Loaded data instructions are acted upon at the end of each individual, loaded byte. 4. To allow for differing microcontroller serial interface formats, the MX805A will work with either polarity Serial clock pulses. t CSOFF CHIP SELECT t CSE t NXT t CSH t NXT SERIAL CLOCK t CK COMMAND DATA 7 6 5 4 3 2 1 MSB 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 LSB FIRST DATA BYTE ADDRESS/COMMAND BYTE LAST DATA BYTE t HIZ REPLY DATA 7 Logic level is not important 6 5 4 3 2 1 0 7 LSB MSB FIRST REPLY DATA BYTE 6 5 4 3 2 1 0 LAST REPLY DATA BYTE Figure 10: C-BUS Timing Information ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor Page 23 of 24 MX805A t CK 70% VDD t CH t CL SERIAL CLOCK (from C) 30% VDD t CDH t CDS COMMAND DATA (from µC) t RDH t RDS REPLY DATA (to µC) Figure 11: Timing Relationships for C-BUS Information Transfer 6.2 Packages A Package Tolerances B DIM. A B C E E1 H J J1 K L P T Y E E1 Y T PIN1 K H L C J1 J MIN. TYP. MAX. 1.270 (32.26) 1.200 (30.48) 0.555 (14.04) 0.500 (12.70) 0.151 (3.84) 0.220 (5.59) 0.600 (15.24) 0.670 (17.02) 0.590 (14.99) 0.625 (15.88) 0.015 (0.38) 0.045 (1.14) 0.015 (0.38) 0.023 (0.58) 0.040 (1.02) 0.065 (1.65) 0.066 (1.67) 0.074 (1.88) 0.121 (3.07) 0.160 (4.05) 0.100 (2.54) 0.008 (0.20) 0.015 (0.38) 7° NOTE : All dimensions in inches (mm.) Angles are in degrees P Figure 12: 24-pin PDIP Mechanical Outline: Order as part no. MX805AP Package Tolerances A Z B Alternative Pin Location Marking E W L T PIN 1 X Y C K H J P DIM. A B C E H J K L P T W X Y Z MIN. TYP. MAX. 0.613 (15.57) 0.299 (7.59) 0.105 (2.67) 0.419 (10.64) 0.020 (0.51) 0.020 (0.51) 0.046 (1.17) 0.597 (15.16) 0.286 (7.26) 0.093 (2.36) 0.390 (9.90) 0.003 (0.08) 0.013 (0.33) 0.036 (0.91) 0.050 (1.27) 0.016 (0.41) 0.050 (1.27) 0.0125 (0.32) 0.009 (0.23) 45° 10° 0° 5° 7° 5° NOTE : All dimensions in inches (mm.) Angles are in degrees Figure 13: 24-pin SOIC Mechanical Outline: Order as part no. MX805ADW ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. Sub-Audio Signaling Processor Page 24 of 24 E B C Package Tolerances K Y DA W J W T PIN 1 MX805A H P G DIM. A B C D E F G H J K P T W Y MIN. TYP. MAX. 0.409 (10.40) 0.380 (9.61) 0.409 (10.40) 0.380 (9.61) 0.146 (3.70) 0.128 (3.25) 0.417 (10.60) 0.435 (11.05) 0.435 (11.05) 0.417 (10.60) 0.250 (6.35) 0.250 (6.35) 0.023 (0.58) 0.018 (0.45) 0.022 (0.55) 0.047 (1.19) 0.048 (1.22) 0.051 (1.30) 0.049 (1.24) 0.009 (0.22) 0.006 (0.152) 30° 45° 6° NOTE : All dimensions in inches (mm.) Angles are in degrees F Figure 14: 24-pin PLCC Mechanical Outline: Order as part no. MX805ALH ã2001 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA Doc. # 20480116.005 All trademarks and service marks are held by their respective companies. CML Microcircuits COMMUNICATION SEMICONDUCTORS CML Product Data In the process of creating a more global image, the three standard product semiconductor companies of CML Microsystems Plc (Consumer Microcircuits Limited (UK), MX-COM, Inc (USA) and CML Microcircuits (Singapore) Pte Ltd) have undergone name changes and, whilst maintaining their separate new names (CML Microcircuits (UK) Ltd, CML Microcircuits (USA) Inc and CML Microcircuits (Singapore) Pte Ltd), now operate under the single title CML Microcircuits. These companies are all 100% owned operating companies of the CML Microsystems Plc Group and these changes are purely changes of name and do not change any underlying legal entities and hence will have no effect on any agreements or contacts currently in force. CML Microcircuits Product Prefix Codes Until the latter part of 1996, the differentiator between products manufactured and sold from MXCOM, Inc. and Consumer Microcircuits Limited were denoted by the prefixes MX and FX respectively. These products use the same silicon etc. and today still carry the same prefixes. In the latter part of 1996, both companies adopted the common prefix: CMX. This notification is relevant product information to which it is attached. CML Microcircuits (USA) [formerly MX-COM, Inc.] Product Textual Marking On CML Microcircuits (USA) products, the ‘MX-COM’ textual logo is being replaced by a ‘CML’ textual logo. Company contact information is as below: CML Microcircuits (UK)Ltd CML Microcircuits (USA) Inc. CML Microcircuits (Singapore)PteLtd COMMUNICATION SEMICONDUCTORS COMMUNICATION SEMICONDUCTORS COMMUNICATION SEMICONDUCTORS Oval Park, Langford, Maldon, Essex, CM9 6WG, England Tel: +44 (0)1621 875500 Fax: +44 (0)1621 875600 [email protected] www.cmlmicro.com 4800 Bethania Station Road, Winston-Salem, NC 27105, USA Tel: +1 336 744 5050, 0800 638 5577 Fax: +1 336 744 5054 [email protected] www.cmlmicro.com No 2 Kallang Pudding Road, 09-05/ 06 Mactech Industrial Building, Singapore 349307 Tel: +65 7450426 Fax: +65 7452917 [email protected] www.cmlmicro.com D/CML (D)/2 May 2002