TP3410 ISDN Basic Access Echo-Cancelling 2B1Q U Transceiver General Description Features The TP3410 is a complete monolithic transceiver for ISDN Basic Access data transmission at either end of the U interface. Fully compatible with ANSI specification T1.601, it is built on National’s advanced double-metal CMOS process, and requires only a single a 5V power supply. A total of 160 kbps full-duplex transmission on a single twisted-pair is provided, with user-accessible channels including 2 ‘B’ channels, each at 64 kbps, 1 ‘D’ channel at 16 kbps, and an additional 4 kbps for loop maintenance. 12 kbps of bandwidth is reserved for framing. 2B1Q Line coding is used, in which pairs of binary bits are coded into 1 of 4 quantum levels for transmission at 80k symbols/sec (hence 2 Binary/ 1 Quaternary). To meet the very demanding specifications for k1 in 10e7 Bit Error Rate even on long loops with crosstalk, the device includes 2 Adaptive Digital Signal Processors, 2 Digital Phase-locked Loops and a controller for automatic activation. The digital interface on the device can be programmed for compatibility with either of two types of control interface for chip control and access to all spare bits. In one mode a Microwire serial control interface is used together with a 2B a D digital interface which is compatible with the Time-division Multiplexed format of PCM Combo devices and backplanes. This mode allows independent time-slot assignment for the 2 B channels and the D channel. Alternatively, the GCI (General Circuit Interface) may be selected, in which the 2B a D data is multiplexed together with control, spare bits and loop maintenance data on 4 pins. Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Applications Y Y Y Y ComboÉ and TRI-STATEÉ are registered trademarks of National Semiconductor Corporation. MICROWIRETM is a trademark of National Semiconductor Corporation. The General Circuit Interface (G.C.I.) is an interface specification of the Group-of-Four European Telecommunications Companies. 2 ‘B’ a ‘D’ channel 160 kbps transceiver for LT and NT Meets ANSI T1.601 U.S. Standard 2B1Q line coding with scrambler/descrambler Range exceeds 18 kft of Ý26 AWG l 70 dB adaptive echo-cancellation and equalization On-chip timing recovery, no precision external components Direct connection to small line transformer Automatic activation controller Selectable digital interface formats: Ð TDM with time-slot assigner up to 64 slots, plus MICROWIRETM control interface Ð GCI (General Circuit Interface), or Ð IDL (Inter-chip Digital Link) Backplane clock DPLL allows free-running XTAL Elastic data buffers meet Q.502 wander/jitter for Slaveslave mode on PBX Trunk Cards and DLC EOC and spare bits access with automatic validation Block error counter 6 loopback test modes Single a 5V supply, 325 mW active power 20 mW idle mode with line signal ‘‘wake-up’’ detector LT, NT-1, NT-2 Trunks, U-TE’s, Regenerators etc. Digital Loop Carrier POTS Pair-Gain Systems Easy Interface to: Ð Line Card Backplanes Ð ‘‘S’’ Interface Device TP3420A Ð Codec/Filter Combos TP3054/7 and TP3075/6 Ð LAPD Processor MC68302, HPC16400 Ð HDLC Controller TP3451 Block Diagram Note: Pin names show Microwire mode. C1995 National Semiconductor Corporation TL/H/9151 TL/H/9151 – 1 RRD-B30M115/Printed in U. S. A. TP3410 ISDN Basic Access Echo-Cancelling U Transceiver September 1994 Connection Diagrams Pin Names for GCI Mode Pin Names for MICROWIRE Mode TL/H/9151 – 3 TL/H/9151–2 Top View Top View Order Number TP3410J See NS Package Number J28A Pin Descriptions Pin No. 24 9 23 Symbol Description GNDA GNDD1 GNDD2 Negative power supply pins, which must be connected together close to the device. All digital signals are referenced to these pins, which are normally at the system 0V (Ground) potential. 5 VCCA Positive power supply input for the analog sections, which must be a 5V g 5% and must be directly connected to VCCD. 8 VCCD Positive power supply input for the digital section, which must be a 5V g 5% and must be directly connected to VCCA. The 15.36 MHz Master Clock input, which requires either a parallel resonance crystal to be tied between this pin and XTAL2, or a CMOS logic level clock input from a stable source (a TTL Logic ‘‘1’’ level is not suitable). This clock does not need to be synchronized to the system clock (BCLK and FS), see Section 5.1. The output of the crystal oscillator, which should be connected to one end of the crystal, if used; otherwise this pin must be left open-circuit. Not recommended to drive additional logic. 21 MCLK/ XTAL 20 XTAL2 10 TSr/ SCLK Pin Symbol No. 22 TSFS Description The Transmit Superframe Sync pin, which indicates the start of each 12 ms transmit superframe at the U Interface. In NT mode this pin is always an output. In LT mode it may be selected to be either an input or CMOS output via Register CR2; when selected as an output the signal is a squarewave. Must be tied low if selected as input yet not driven. 25 LSD/RSFS This pin is an open-drain n-channel Line Signal Detector output, which is normally high-impedance and pulls low only when the device is powered down and an incoming wake-up signal is detected from the far-end. As an option this pin can be programmed to be an output indicating the start of the received superframe at the U interface; an external pull-up resistor is required. The RSFS signal indicates the start of each 12 ms receive superframe from the U Interface and is available in NT and LT modes. The Received Superframe Synch clock output is accessible on pin 25 by writing X’1C04 and X’100C (or X’100E) during device initialization. See TP3410 users manual AN-913, Part II Section 4.18). 1 Lo a Transmit 2B1Q signal differential outputs 4 Lob to the line transformer. When used with an appropriate 1:1.5 step-up transformer and the line coupling circuit recommended in the Applications section, the line signal conforms to the output specifications in the ANSI standard. This pin has 2 functions: in LT mode it is an open-drain n-channel TSr output, which goes low only during the time-slots assigned to the B1 and B2 channels at the Br pin in order to enable the TRI-STATE control of the backplane line-driver. In NT mode it is a full CMOS 15.36 MHz synchronous clock output which is frequencylocked to the received line signal (unlike the XTAL pins it is not free-running). 2 Pin Descriptions (Continued) PIN DESCRIPTIONS SPECIFIC TO MICROWIRE MODE ONLY (MW e 1) Pin No. Symbol Pin No. 2 3 17 CCLK The Microwire control channel Clock input, which may be asynchronous with BCLK. 27 CS The Chip Select input, which enables the Control channel data to be shifted in and out when pulled low. When high, this pin inhibits the Control interface. 26 INT 16 Dx 15 Dr 14 DCLK The Interrupt output, a latched open-drain output signal which is normally high-impedance, and goes low to indicate a change of status of the loop transmission system. This latch is cleared when the Status Register is read by the microprocessor. When the D-port is enabled this pin is the digital input for D channel data to be transmitted to the line clocked by DCLK or BCLK, see Register CR2. When the D-port is disabled via CR2, this pin must be tied to GND. When the D-port is enabled this pin is the TRI-STATE output for D channel data to be received from the line clocked by DCLK or BCLK, see Register CR2. When the D-port is enabled, in DSI Slave or Master mode, this is a 16 kHz clock CMOS output for D channel data. When the D-port is disabled or not used, this pin must be left open-circuit. Symbol Li a Lib 28 MW 12 BCLK 6 7 FSa FSb 13 Bx 11 Br 18 19 CI CO Description Receive 2B1Q signal differential inputs from the line transformer. For normal fullduplex operation, these pins should be connected to the Lo g pins through the recommended coupling circuit, as shown in the Applications section. The Microwire/GCI Select pin, which must be tied to VCCD to enable the Microwire Interface with any of the data formats at the Digital System Interface. The Bit Clock pin, which determines the data shift rate for ‘B’ and ‘D’ channel data on the digital interface side of the device. When Digital System Interface (DSI) Slave mode is selected (see Digital Interfaces section), BCLK is an input which may be any multiple of 8 kHz from 256 kHz to 4.096 MHz. It need not be synchronous with MCLK. When DSI Master mode is selected, this pin is a CMOS output clock at 256 kHz, 512 kHz, 1.536 MHz, 2.048 MHz or 2.56 MHz, depending on the selection in Command Register 1. It is synchronous with the data on Bx and Br. In DSI Slave mode, this pin is the Transmit Frame Sync pulse input, requiring a positive edge to indicate the start of the active channel time for transmit B1 channel data into Bx. In DSI Master mode, this pin is a Frame Sync CMOS output pulse conforming with the selected Digital Interface format. In DSI Slave mode, this pin is the Receive Frame Sync pulse input, requiring a positive edge to indicate the start of the active channel time of the device for receive B channel data out from Br (see DSI Format section). In DSI Master mode this pin is a Frame Sync CMOS output pulse conforming with the selected Digital Interface format. The digital input for B and, if selected, D channel data to be transmitted to the line; must be synchronous with BCLK. The TRI-STATE output for B and, if selected, D channel data received from the line; it is synchronous with BCLK. The Microwire control channel data input. The Microwire control channel TRI-STATE output for status information. When not enabled by CS, this output is high-impedance. Description PIN DESCRIPTIONS SPECIFIC TO GCI MODE ONLY (MW e 0) *Crystal specifications: 15.36 MHz g 50 ppm parallel resonant; RS s 20X. Load with 33 pF to GND each side ( a 7 pF due to pin capacitance). 3 Pin No. 28 MW 27 MO 12 BCLK Symbol Description The Microwire/GCI select input, which must be tied to GND to enable the GCI mode at the Digital System Interface. The GCI Master/Slave select input for the clock direction. Connect this pin low to select BCLK and FSa as inputs i.e., GCI Slave; Selection of LT or NT mode must be made in register CR2. When MO is connected high, NT Mode is automatically selected, and BCLK, FSa and FSb are outputs, i.e., the GCI Master, see Section 8. The Bit Clock pin, which controls the shifting of data on the Bx and Br pins, at a rate of 2 BCLK cycles per data bit. When GCI Slave mode is selected (see Digital Interfaces section), BCLK is an input which may be any multiple of 16 kHz from 512 kHz to 6.144 MHz. It need not be synchronous with MCLK. When GCI Master mode is selected, this pin is a CMOS output clock at 512 kHz or 1.536 MHz, depending on the connection of the S2/CLS pin. It is synchronous with the data on Bx and Br. Pin Descriptions (Continued) Pin No. Symbol 13 Bx 11 Br 6 FSa Pin No. Description Symbol 17 S2/CLS 19 S1 7 SO/FSb The digital input for multiplexed B, D and control data clocked by BCLK at the rate of 1 data bit per 2 BCLK cycles, and 32 data bits per 8 kHz frame defined by FSa. The open-drain n-channel output for multiplexed B, D and control data clocked by BCLK at the rate of 1 data bit per 2 BCLK cycles, and 32 data bits per 8 kHz frame defined by FSa. A pull-up resistor is required to define the logical 1 state. In GCI Slave mode (MO connected low), this pin is the 8 kHz Frame Sync pulse input, requiring a positive edge to indicate the start of the GCI slot time for both transmit and receive data at Bx and Br. In GCI Master mode, this pin is the 8 kHz Frame Sync CMOS output pulse. 18 ES1 16 ES2 15 LEC 4 ( ( Description In GCI Slave mode (MO e 0): input pins S2, S1 and S0 together provide a 3-bit binary-coded select port for the GCI channel number; S2 is the msb. These pins must be connected either to VCCD or GND to select the 1-of-8 GCI slots which are available if BCLK t 4.096 MHz is used. In GCI Master mode (MO e 1) S2/CLS is the GCI Clock Select input. Connect this pin high to select BCLK e 1.536 MHz; connect CLS low to select BCLK e 512 kHz. SO/FSb is a Frame Sync CMOS output pulse which identifies the B2 channel. While in GCI mode, the ES1, ES2 pins are local input pins. The status of the pins can be accessed via the RXM56 register bits 5,6 corresponding to ES1, ES2. Latched External Control output, which is the output of a latched bit in the TXM56 Register. Functional Description 1.1 Power-On Initialization 2.0 TRANSMISSION SECTION When power is first applied, power-on reset circuitry initializes the TP3410 and puts it into the power-down state, in which all the internal circuits including the Master oscillator are inactive and in a low power state except for the LineSignal Detect circuit; the line outputs Lo a /Lob are in a high impedance state. All programmable registers and the Activation Sequence Controller are reset. All states in the Command Registers initialize as shown in their respective code tables. The desired modes for all programmable functions may be selected by writing to these registers via the control channel (Microwire or Monitor channel, as appropriate). Microwire is functional regardless of whether the device is powered up or down, whereas the GCI channel requires the BCLK to be running. 2.1 Line Coding And Frame Format For both directions of transmission, 2B1Q coding is used, as illustrated in Figure 1 . This coding rule requires that binary data bits are grouped in pairs, and each pair is transmitted as a symbol, the magnitude of which may be 1 out of 4 equally spaced voltage levels (a ‘‘Quat’’). There is no symbol value at 0V in this code, the relative quat magnitudes being g 1 (the ‘‘inner’’ levels) and g 3 (the ‘‘outer’’ levels). No redundacy is included in this code, and in the limit there is no bound to the RDS, although scrambling controls the RDS in a practical sense ( RDS is the Running Digital Sum, which is the algebraic summation of all symbol values in a transmission session). The frame format used in the TP3410 follows the ANSI standard, shown in Table I. Each complete frame consists of 120 quats, with a line bit rate of 80 kq/s, giving a frame duration of 1.5 ms. A 9 quat syncword defines the framing boundary. Furthermore, a ‘‘superframe’’ consisting of 8 frames is defined in order to provide sub-channels within the spare bits M1 to M6. Inversion of the syncword defines the superframe boundary. Prior to transmission, all data, with the exception of the syncword, is scrambled using a selfsynchronizing scrambler to implement the specified 23rd-order polynomial. Descrambling is included in the receiver. 1.2 Power-Up/Power-Down Control Before powering up the device, the Configuration Registers should be programmed with the required modes. In Microwire mode and GCI Slave mode, the device is powered up and the MCLK started by writing the PUP command, as described in the Activation section. In GCI Master mode, there are 2 methods of powering up the device: the Bx data input can be pulled low (local power-up command) or the 10 kHz wake-up tone may be received from the far-end. The power-down state may be re-entered by writing a Power-down command. In the power-down state, all programmed register data is retained. Also, if the loop had been successfully activated and deactivated, the adaptive circuits are ‘‘frozen’’ and the coefficients in the Digital Signal Processors are stored to enable rapid reactivation (‘‘warmstart’’). 1.3 Reset A software reset command is provided to enable the clearing of the Activation sequencer without disconnecting the power supply to the device, see the Activation section. First Bit (Sign) Second Bit (Magnitude) Quat Pulse Amplitude (Note 1) 1 1 0 0 0 1 1 0 a3 a1 b1 b3 a 2.5V a 0.83V b 0.83V b 2.5V Note 1: For isolated pulses into a 135X termination with recommended transformer interface. TL/H/9151 – 25 FIGURE 1. 2B1Q Line-Coding Rule 5 Functional Description (Continued) Framing 12x(2B a D) Overhead Bits (M1 –M6) Quat Positions 1–9 10– 117 118s 118m 119s 119m 120s 120m Bit Positions 1–18 19– 234 235 236 237 238 239 240 SuperframeÝ Basic FrameÝ Sync Word 2B a D M1 M2 M3 M4 M5 M6 1 1 ISW 2B a D eoca1 eoca2 eoca3 act 1 1 2 SW 2B a D eocdm eoci1 eoci2 dea 1 febe 3 SW 2B a D eoci3 eoci4 eoci5 1 crc1 crc2 4 SW 2B a D eoci6 eoci7 eoci8 1 crc3 crc4 5 SW 2B a D eoca1 eoca2 eoca3 1 crc5 crc6 6 SW 2B a D eocdm eoci1 eoci2 1 crc7 crc8 7 SW 2B a D eoci3 eoci4 eoci5 uoa crc9 crc10 8 SW 2B a D eoci6 eoci7 eoci8 aib crc11 crc12 1 ISW 2, 3, . . . (a) Network x NT Framing 12x(2B a D) Quat Positions 1–9 10– 117 118s 118m 119s 119m 120s 120m Bit Positions 1–18 19– 234 235 236 237 238 239 240 SuperframeÝ Basic FrameÝ Sync Word 2B a D M1 M2 M3 M4 M5 M6 1 1 ISW 2B a D eoca1 eoca2 eoca3 act 1 1 2 SW 2B a D eocdm eoci1 eoci2 ps1 1 febe 3 SW 2B a D eoci3 eoci4 eoci5 ps2 crc1 crc2 4 SW 2B a D eoci6 eoci7 eoci8 ntm crc3 crc4 5 SW 2B a D eoca1 eoca2 eoca3 cso crc5 crc6 6 SW 2B a D eocdm eoci1 eoci2 1 crc7 crc8 7 SW 2B a D eoci3 eoci4 eoci5 1 crc9 crc10 8 SW 2B a D eoci6 eoci7 eoci8 1 crc11 crc12 1 ISW 2, 3, . . . (b) NT Overhead Bits (M1 –M6) x Network Note: 8 c 1.5 ms Basic Frames e 12 ms/Superframe. NT-to-Network superframe is offset from Network-to-NT superframe by 60 g 2 quats (about 0.75 ms). All bits other than the Sync Word are scrambled. ntm e NT in test mode bit ( e 0 to indicate test mode) ps1, ps2 e power status bits ( e 0 to indicate power problems) e pair of bits forming quaternary symbol Quat Symbols & Abbreviations e start-up bit ( e 1 during start-up) act e alarm indication bit ( e 0 to indicate interrupaib tion) e cyclic redundacy check: covers 2B a D a M4 crc cso dea eoc febe 1 e most significant bit 2 e next significant bit etc. e cold-start-only bit ( e 1 to indicate cold-startonly) sai uoa ‘‘1’’ ‘‘1*’’ e turn off bit ( e 0 to announce turn off) e embedded operations channel e e e e s e sign bit (first in quat) m e magnitude bit (second in quat) S-activation-indication bit ( e 1 for S/T activity) U-only-activation bit ( e 1 to activate S/T) reserved bit for future standard ( e 1) network indicator bit ( e 1, reserved for network use) 2B a D e user data, bits 19 – 234 in frame e M-channel, bits 235 – 240 in frame M SW/ISW e synchronization word/inverted synchronization word, bits 1 – 18 in frame a e address bits dm e data/message indicator (0 e data, 1 e message) i e information (data or message) e far end block error bit ( e 0 for errored superframe) TABLE I. 2B1Q Superframe Format and Overhead Bit Assignments 6 Functional Description (Continued) 480 ms. If a loss-of-sync condition persists for 480 ms the device will cease transmitting and go into a RESET state. 2.2 Line Transmit Section Data to be transmitted to the line consists of the customer’s 2B a D channel data and the data from the maintenance processor, plus other ‘‘spare’’ bits in the overhead channels. This data is multiplexed and scrambled prior to addition of the syncword. A pulse waveform synthesizer then drives the transmit filter, which in turn passes the line signal to the line driver. The differential line-driver outputs, Lo a and Lob, are designed to drive a transformer through an external termination circuit. A 1:1.5 transformer, designed as shown in the Applications section, results in a signal amplitude of nominally 2.5V pk on the line for single quats of the outer ( g 3) levels. Note, however, that because of the RDS accumulation of the 2B1Q line code, continuous random data will produce signal swings considerably greater than this on the line. Short-circuit protection is included in the output stage; overvoltage protection must be provided externally. While the receiver is synchronized, data is descrambled using the specified polynomial, and the individual channels demultiplexed and passed to their respective processing circuits. Whenever the loop is deactivated, either powered up or powered down, a Line Signal Detect circuit is enabled to detect the presence of an incoming 10 kHz wake-up tone if the far-end starts to activate the loop. The LSD circuit generates an interrupt and, if the device is powered down, pulls the LSD pin low; either of these indicators may be used to alert an external controller, which must respond with the appropriate commands to initiate the activation sequence (see the Activation section). 3.0 ACTIVATION CONTROL: OVERVIEW The TP3410 contains an automatic sequencer for the complete control of the start-up activation sequence specified in the ANSI standard. Both the ‘‘cold-start’’ and the fast ‘‘warm-start’’ are supported. Interaction with an external controller requires only Activate Request and Deactivate Request commands, with the option of inserting breakpoints in the sequence for additional external control if desired. Automatic control of the ‘‘act’’ and ‘‘dea’’ bits in the M4 bit positions is provided, along with the specified 40 ms and 480 ms timers used during deactivation. A 15 second default timer is also included, to prevent system lock-up in the event of a failed activation attempt. Section 11 gives an overview of the activation handshake between the TP3410 and the controller. See TP3410 User’s Manual AN-913 for additional information. 2.3 Line Receive Section The receive input signal should be derived from the transformer by means of a coupling circuit as shown in the Applications section. At the front-end of the receive section is a continuous filter followed by a switched-capacitor low-pass filter, which limits the noise bandwidth. A Hybrid Balance Filter provides a degree of analog echo-cancellation in order to limit the dynamic range of the composite signal. An A/D converter then samples the composite received signal prior to the cancellation of the ‘‘echo’’ from the local transmitter by means of an adaptive digital transversal filter (i.e., the ‘‘echo-canceller’’). Following this, the attenuation and distortion (inter-symbol interference) of the received signal from the far-end, caused by the transmission line, are equalized by a second adaptive digital filter configured as a Decision Feedback Equalizer (DFE), thereby restoring a ‘‘flat’’ channel response with maximum received eye opening over a wide spread of cable attenuation characteristics. From the received line signal, a Timing Recovery circuit based on a DPLL (Digital Phase-Locked Loop) recovers a low-jitter clock for optimum sampling of the received symbols. The MCLK input provides the reference clock for the DPLL at 15.36 MHz. Received data is then detected, with automatic correction for line signal polarity if necessary, and a flywheel synchronization circuit searches for and locks onto the frame and superframe syncwords. Frame lock will be maintained until errored sync words are detected for 4.0 MAINTENANCE FUNCTIONS: OVERVIEW 4.1 M Channel Processing In each frame of the superframe there are 6 ‘‘Overhead’’ bits assigned to various control and maintenance functions of the DSL. Some processing of these bits may be programmed via the Command Registers, while interaction with an external controller provides the flexibility to take full advantage of the maintenance channels. New data written to any of the overhead bit Transmit Registers is resynchronized internally to the next available complete superframe or half-superframe, as appropriate. In addition, the SFS pin may be used to indicate the start of each superframe in 1 direction, see Figure 2 and Register CR2. TL/H/9151 – 26 FIGURE 2. Superframe Sync Pin Timing 7 Functional Description (Continued) 4.2 Embedded Operations Channel 5.0 DIGITAL INTERFACE: ALL FORMATS The EOC channel consists of 2 complete 12-bit messages per superframe, distributed through the M1, M2 and M3 bits of each half-superframe as shown in Table I. Each message is composed of 3 fields; a 3-bit address identifying the message destination, a 1-bit indicator for the data mode, i.e., encoded message or raw data, and an 8-bit information byte. The Microwire port or GCI Monitor Channel provides access to the complete 12 bits of every message in the TX EOC and the RXEOC Registers. If one of the defined encoded messages is received, e.g., Send Corrupted CRC, then the appropriate Command Register instruction must be written to the device to invoke the function. 5.1 Clocking 4.3 M4 Bits The M4 bit position of every frame is a transparent channel in which are transmitted data bits loaded from the M4 Transmit Register TXM4, one byte per superframe. On the receive side the M4 bits from one complete superframe are sent to a checking circuit which holds each new M4 byte and compares it against the previous M4 byte(s) for validation prior to sending it to the RXM4 Receive Register; Register OPR provides several options for control of this validation. In LT applications (network end of the Loop), the Digital System Interface (DSI) normally accepts BCLK and FS signals from the network, requiring the selection of DSI or GCI Slave mode in Register CR1. A Digital Phase-Locked Loop (DPLL Ý2) on the TP3410 allows the MCLK frequency to be plesiochronous (i.e. free-running) with respect to the network clocks, (BCLK and the 8 kHz FSa input). With a tolerance on the MCLK oscillator of 15.36 MHz g 100 ppm, the lock-in range of DPLL2 allows the network clock frequency to deviate up to g 50 ppm from nominal. In NT applications, when the device is in NT mode and is slaved to loop timing recovered from the received line signal, DSI or GCI Master mode should normally be selected. In this case BCLK, FS and SCLK (15.36 MHz) signals are outputs which are phase-locked to the recovered clock. A slave-slave mode is also provided, however, in which the Digital Interface data buffers on the TP3410 allow BCLK and FSa/b to be input from an external source, which must be frequency-locked (but may take an arbitrary phase) to the received line signal; in this case DSI or GCI Slave mode should be selected. 4.4 Spare M5 And M6 Bits Overhead bits M5 and M6 in frame 1 (M51 and M61) and M5 in frame 2 (M52) are transparently transmitted from the Transmit M56 Spare Bit Register to the line. In the receive direction, data from these bit positions is sent to a checking circuit which holds the new M5/M6 spare bits and compares them against the previous M5/M6 bits for validation prior to sending them to the Receive M56 Spare Bit Register; the OPR Register provides several options for control of this validation. 5.2 Data Buffers The TP3410 buffers the 2B a D data at the Digital Interface in elastic FIFOs, which are 3 frames deep in each direction. When the Digital Interface is a timing slave these FIFOs compensate for relative jitter and wander between the Digital Interface clocks (BCLK and FSa/b) and bit and frame timing at the Line Interface. Each buffer can absorb wander up to 18 ms in t 10 secs without ‘‘slip’’, exceeding CCITT recommendation Q.502. Excessive wander causes a controlled slip of one complete frame. 4.5 CRC Circuit In the transmit direction an on-chip crc calculation circuit automatically generates a checksum of the 2B a D a M4 bits using the polynomial x12 a x11 a x3 a x2 a x a 1. Once per superframe the crc is transmitted in the specified M5 and M6 bit positions (see Table I). In the receive direction a checksum is again calculated on the same bits as they are received and, at the end of the superframe, compared against the crc transmitted with the data. The result of this comparison generates a ‘‘Far End Block Error’’ bit (the febe bit), which is transmitted back towards the other end of the DSL in the next superframe. If there are no errors in a superframe, febe is set e 1, and if there is one or more errors febe is set e 0. The TP3410 also includes a readable 8-bit Block Error Counter BEC1, which is decremented by 1 each superframe in which febe e 0 or nebe e 0 is received. Section 10.5 describes the operation of this counter. On first application of power, and after the software reset (X’1880, X’1800), both the ECT1 as well as BEC1 are initialized to X’FF. See the Block Error Counter section for more details. 6.0 DIGITAL INTERFACE DATA FORMATS IN MICROWIRE MODE (MW e 1) When the MW pin is tied high to enable the Microwire Port for control and status, the Digital System Interface on the TP3410 provides a choice of four multiplexed formats for the B and D channel data, as shown in Figure 3 . These apply in both LT and NT modes of the device, and selection is made via Register CR1. Selection of DSI Master or Slave mode must also be made in CR1. Within each format there is also an independent selection available to either multiplex the D channel (Tx and Rx) data on the same pins as the B channels, or via the separate D-channel access pins, DCLK, Dx and Dr, see Section 6.3. Format 1: In Format 1, the 2B a D data transfer is assigned to the first 18 bits of the frame on the Bx and Br pins. Channels are assigned as follows: B1 (8 bits), B2 (8 bits), D (2 bits), with the remaining bits ignored until the next frame sync pulse. When the D channel port is enabled (see CR2), only the 2 B channels use the Bx and Br pins; the D bits are assigned to the 17th and 18th bits of the frame on the Dx and Dr pins. Figure 3-1 shows this format in DSI Slave Mode, and Figure 3-4 shows DSI Master Mode. 8 Functional Description (Continued) on the Dx and Dr pins (see D-Channel Port section). Figure 3-3 shows this format in DSI Slave Mode, and Figure 3-6 shows DSI Master Mode; see also Section 6.2. Format 4: This is similar to the GCI format for the 2B a D channels, but excludes the Monitor channel and C/I channel. Channels are assigned to the first 26 bits of each frame as follows: B1 (8 bits), B2 (8 bits), ignored (8 bits), D (2 bits). The remaining bits in the frame are ignored until the next frame sync pulse. The relationship between BCLK and data is the same as in the GCI mode for GCI Channel 0, see Figure 7 (in DSI Master Mode, BCLK e 512 kHz and FSa is a square wave output). Format 2: Format 2 is the IDL, in which the 2B a D data transfer is assigned to the first 19 bits of the frame on the Bx and Br pins. Channels are assigned as follows: B1 (8 bits), D (1 bit), 1 bit ignored, B2 (8 bits), D (1 bit), with the remaining bits ignored until the next frame sync pulse. Figure 3-2 shows this format in DSI Slave Mode, and Figure 3-5 shows DSI Master Mode. Format 3: This format provides time-slot assignment capability for the B1 and B2 channels, which can be independently assigned to any 8-bit wide timeslot from 64 (or less) on the Bx and Br pins; the Transmit and Receive directions are also independently assignable. Also the D channel can be assigned to any 2-bit wide time-slot from 256 (or less) on the Bx and Br pins (D port disabled) or TL/H/9151 – 5 FSa defines B1 channel for Tx. FSb defines B1 channel for Rx. FIGURE 3-1. DSI Format 1: Slave Mode TL/H/9151 – 6 Delayed timing mode must be selected; Time-slot immediate mode only (no TSA). FIGURE 3-2. DSI Format 2 (IDL): Slave Mode 9 Functional Description (Continued) TL/H/9151 – 7 Transmit slots are numbered relative to FSa, and receive slots relative to FSb. Shown with examples of offset frames and Time-slot Assignments. FIGURE 3-3. DSI Format 3 (Time-Slot Assignment) : Slave Mode TL/H/9151 – 8 FSa defines B1 channel for Tx and Rx. FSb defines B2 channel for Tx and Rx. FIGURE 3-4. DSI Format 1: Master Mode TL/H/9151 – 9 FIGURE 3-5. DSI Format 2 (IDL): Master Mode TL/H/9151 – 10 Transmit and Receive slots are numbered relative to FSa. FIGURE 3-6. DSI Format 3: Master Mode 10 Functional Description (Continued) 6.1 FS Relationship To Data (Microwire Mode) 6.3 D Channel Port Selection (Microwire Mode) For applications on a line-card, in DSI Slave Mode, the B and D channel slots can be interfaced to a Time-Division Multiplexed (TDM) bus and assigned to a time-slot. The repetition rate of the FS input signals must be 8 kHz and must be synchronized to the BCLK input, which may be any frequency from 256 kHz to 4.096 MHz in 8 kHz increments. Two different relationships may be established between the FS inputs and the actual time-slots on the PCM busses by setting the DDM bit in Control Register CR1, see Figures 3, 11 and 12 . Non-delayed data mode is similar to long frame timing on the TP3050/60 series of devices (COMBO I): the time-slots are defined by the 8-bit duration FSa and FSb signals. The alternative is to use Delayed Data Mode, which is similar to short frame sync timing on COMBO I, in which each FS input indicates the start of the first time-slot. Serial B channel data is shifted into the Bx input during each assigned Transmit time-slot on the falling edges of BCLK. During each assigned Receive time-slot, the Br output shifts data out on the rising edges of BCLK. Also, with the device in LT Mode, the TSr pin is an open drain n-channel pulldown output which goes low during the selected time-slots for the received B1 and B2 channels at the Br pin to control the TRI-STATE Enable of a backplane line-driver; it is highimpedance at all other times. In NT Mode, when DSI Master mode is selected, FSa and FSb are outputs indicating the B1 (or TS0) and the B2 (or TS1) channels respectively. BCLK is also an output at the serial data shift rate, which is dependent on the format selected. Again, either a delayed or non-delayed relationship between FSa, FSb and the start of the first time-slot can be selected. In any of the DSI Formats, the 2 D channel bits per frame may either be multiplexed with the B channels on the Bx and Br pins, or may be accessed via the separate D channel port consisting of Dx and Dr. Furthermore, when using the separate D port the data shift clock may either be a continuous, unframed data stream using the 16 kHz clock output at DCLK, see Figure 4 , or may use the BCLK, see Figure 5 . Selection of these options is via Control Register CR2. 6.2 B Channel Time-slot Assignment; Format 3 Only (Microwire Mode) In Format 3 only, the TP3410 provides programmable timeslot assignment for selecting the Transmit and Receive B channel time-slots. Following power-on, the device is automatically in Non-delayed Data Mode; if Delayed Data Mode is required it must first be selected (see CR1) prior to using Time-slot Assignment, and the FS pulses must conform to the Delayed Data timing format. The actual transmit and receive time-slots are then determined by the internal Timeslot Assignment counters, programmed via Control Registers TXB1, TXB2, RXB1 and RXB2. Normally used in DSI Slave mode, Format 3 allows a frame to consist of up to 64 time-slots of 8 bits each with BCLK up to 4.096 MHz. A new assignment becomes active on the second frame following the end of the 16-bit Chip Select. 6.4 D Channel Time-Slot Assignment In addition to B channel TSA, Format 3 allows independent Time Slot Assignment for the Transmit and Receive D channels, which may be programmed via Registers TXD and RXD. As with the B channels, up to 64 time-slots are available if BCLK e 4.096 MHz, and in addition the 2 D bits may be assigned, in pairs, to specific bit locations within the time-slot; that is in bits 1 and 2; 3 and 4; 5 and 6; or 7 and 8. D channel TSA may be used either with the D channel multiplexed with the B channel data, or with the separate D Channel port clocked with BCLK; it cannot be used with the 16 kHz clock option at DCLK. Summary of DSI Slave Mode Options Format Number Function FSa FSb Non-Delayed Timing? Delayed Timing? Tx and Rx Frames with Any Phase? TSA Available? D Port Available? 1 2 3 4 Tx B1 Rx B1 Yes Yes Yes Tx B1 Rx B1 No Yes Yes Tx TS0 Rx TS0 Yes Yes Yes Tx B1 Rx B1 Yes No Yes No Yes No Yes Yes Yes No Yes Summary of DSI Master Mode Options Format Number Function 1 2 3 4 FSa FSb FS Formats B1 B1 TS0 B1 B2 B2 TS1 B2 NonDelayed NonNonDelayed Only Delayed Delayed and and Only Delayed Delayed TSA Available? No No Yes No D Port Available? Yes Yes Yes Yes Note: All Formats: Tx and Rx frames always aligned. TL/H/9151 – 11 FIGURE 4. D-Port Interface Timing Using DCLK in 16 kHz Mode 11 Functional Description (Continued) TL/H/9151 – 12 FIGURE 5-1. Format 1 TL/H/9151 – 13 FIGURE 5-2. Format 2 TL/H/9151 – 14 FIGURE 5-3. Format 3 Shown with example of Time-slot Assignment, and FSa e FSb FIGURE 5. D-Port Interface Timing Using BCLK dress and the second byte is the data byte. Status Registers request service under control of the Interrupt Stack, with the priority order listed in Table III. To shift data to and from the TP3410, CCLK must be pulsed high 16 times while CS is low. Data on the CI input is shifted into the serial input register on the rising edge of each CCLK pulse; simultaneously, data is shifted out from CO on each falling edge of CCLK. Bit 7 of byte 1 is shifted first. CS must return high at the end of the 2nd byte, after which the contents of the input shift register are decoded, and the data is loaded into the appropriate programmable register. Pulling CS low also clears the INT pin if it was pulled low; if another interrupt condition is queued on the Interrupt Stack it can only pull the INT pin low when CS is high. When CS is high the CO pin is in the high-impedance state, enabling the CO pins of many devices to be multiplexed together. 7.0 MICROWIRE CONTROL PORT (MW e 1) When Format 1, 2, 3 or 4 is used, control information and maintenance channel data is written into and read back from the TP3410 via the Microwire port consisting of the control clock CCLK; the serial data input, CI, and output, CO; the Chip Select input, CS and the interrupt output INT. The MW pin must be tied high to enable this port, and the port may be used regardless of whether the device is powered up or down. Figures 6 and14 show the timing, which is compatible with the Microwire port on the HPC and COPs families of microcontrollers, and Tables II and III list the control functions and status indicators. All read and write operations require 2 contiguous bytes. As shown in Tables II and III, the first byte is the register ad- 12 Functional Description (Continued) The TP3410 has an enhanced MICROWIRE port such that it can connect to standard MICROWIRE master devices (such an NSC’s HPC and COP families) as well as the SCP (serial control port) interface master from the Motorola micro-controller family. SCP is supported on devices such as MC68302 or the MC145488 HDLC. TP3410 supports two popular formats used in typical terminal equipment applications. 1. CCLK idling LOW when CS pin is inactive HIGH, pulsing LOW/HIGH/LOW for 16 clocks, then returning back to LOW for idle condition. Data is output on CO pin on the negative edge and data sampled in on the positive edge of CCLK. This format (shown in Figure 14b ) is normally used with NSC’s microcontrollers from the HPC or the COP8 family. 2. CCLK idling HIGH when CS pin inactive HIGH, pulsing HIGH/LOW/HIGH for 17 clocks, then returning back to HIGH for idle condition. Data is output on CO pin on the negative edge and data sampled in on the positive edge of CCLK. This format (shown in Figure 14c ) is normally used with other alternate microcontrollers in the industry. The first 16 clock pulses are the normal low-going pulses to shift and sample the microwire data. The 17th pulse is generated with software by toggling the CCLK clock polarity bit on the SCP port of MC6302 or MC145488. It is necessary to deactivate the CS pin (bring it high) while the CCLK is low as shown in Figure 14c . 8.1 GCI Physical Interface The interface physically consists of four wires: Ð Transmit data to line: Bx Ð Receive data from line: Br Ð Bit clock at 2 cycles/bit: BCLK Ð 8 kHz frame sync: FSa Data is synchronized by the BCLK and FSa clock inputs. FSa insures re-initialization of the time-slot counter at the beginning of each 8 kHz frame, with the rising edge of FSa being the reference time for the first GCI channel bit. Data is clocked in both directions at half the BCLK input frequency. Data bits are output from the device on a rising edge of BCLK and sampled on the second falling edge of BCLK; unused slots are high impedance. Br is an open-drain nchannel output, with internal detection for contention resolution on the Monitor and C/I channels between devices attempting to use the same GCI channel (typically in a TE application). A device may be either the Master or Slave of the GCI timing. As a Master it is the source of BCLK, FSa and FSb, which are synchronized to the data received from the line, and GCI channel 0 is always used. As a GCI Slave, BCLK and FSa must be sourced externally, typically from a system backplane, and pins S0 – S2 must be connected high or low to select the required GCI channel. To use the single channel mode, a 512 kHz BCLK is required, and S2, S1 and S0 must be connected to GND (GCI Channel 0). To use the multiplex mode with a GCI Slave device, the 4 pins are commoned between up to 8 devices, forming a ‘‘wire-AND’’ connection with the Br pins. The BCLK frequency must be at least n c 512 kHz, where n is the number of devices. In fact BCLK may be operated up to 6144 kHz if required, to leave up to 4 additional GCI channels unoccupied by TP3410’s (and available for other uses). Clock and channel selection are shown in the following table: 8.0 GCI MODE (MW e 0) Selected by tying the MW pin low, the GCI interface is designed for systems in which PCM and control data are multiplexed together into 4 contiguous bytes per 8 kHz frame. Furthermore, in Subscriber Line Cards and NT1–2’s (where the Digital Interface is slaved to external timing) up to 8 GCI channels may be carried in 1 frame of a GCI multiplex, with a combined bit rate from 256 kb/s up to 3088 kb/s. Pin-programmable GCI-channel assignment for 8 GCI channels is provided. Note that GCI mode on the TP3410 requires messages in the Embedded Operations Channel to be processed by a local microcontroller. In Line card and TE applications, GCI mode can be used with a device such as the TP3451 HDLC controller to provide the interface for the microcontroller to access the EOC Registers. To use the device in an NT-1 or Regenerator, a microcontroller is required and Microwire mode should be used on the TP3410. Pin Name LT and NT1 – 2 MW 0 NT1 and TE 0 MO 0 (GCI Slave) 1 (GCI Master) S2/CLS S2 (msb) CLS e 0: 512 kHz CLS e 1: 1536 kHz S1 S1 0 S0/FSb S0 (lsb) FSb TL/H/9151 – 15 FIGURE 6. Microwire Control Port Timing: MW e 1 13 Functional Description (Continued) device is active in that channel). To initiate a transfer, a device must first verify that it has received the A bit e 1 for at least 2 consecutive GCI frames from the other device before starting the transfer. It then sends the first byte in the Monitor channel, with the associated E bit e 0, and repeats the byte in the next GCI frame. Normally, the receiving device will verify receiving the same byte in 2 consecutive frames and acknowledge this by setting A e 0 for at least 2 frames. If not, the message is aborted by sending A e 0 for only 1 frame. On detecting the acknowledgement, the sending device then sends the 2nd of the 2 bytes in 2 consecutive GCI frames (or until it is acknowledged), with E e 1 to indicate this is the last byte of the transfer. The receiver verifies this byte is the same for 2 frames and sends an acknowledgement by sending A e 1 in the next frame. If an abort is required, the receiver will maintain A e 1 for another frame. If a Monitor channel message originated by the TP3410 is aborted, it will repeat the complete message until it is successfully acknowledged. 8.2 GCI Frame Structure Figure 7 shows the frame structure at the GCI interface. One GCI channel supports one TP3410 using a bandwidth of 256 kbit/s, consisting of the following channels multiplexed together in an 8 kHz frame: Ð B1 channel at 8 bits per frame; Ð B2 channel at 8 bits per frame; Ð Monitor (M) channel at 8 bits per frame; Ð Signalling and Control (SC) channel, which is structured as follows: D Channel at 2 bits per frame; C/I channel at 4 bits per frame; A bit, for acknowledgement of M channel bytes; E bit, which indicates byte boundaries when multiplebyte messages are transferred via the M channel. 8.3 Monitor Channel The GCI Monitor channel (byte 3) is used to access all the Command Registers shown in Table II, with the exception of the Activation Control Register, and all the Status Registers shown in Table III with the exception of the Activation Indication Register. Each access to or from one of the listed registers requires a 2-byte message transfer. As shown in Tables II and III, the first byte from the originating device contains the register address, and the second byte is the data byte. Status Registers originate messages in the Monitor channel under control of the Interrupt Stack (in the same manner as when the TP3410 is used in Microwire Mode). In addition a protocol is used, based on the E and A bits in byte 4, to provide an acknowledgement of each Monitor channel byte in either direction, see Figure 8 . When no Monitor Channel message is being transferred, the E bit, and the A bit in the reverse direction, are high-impedance (and pulled high by the external resistor if no other 8.4 C/I Channel The C/I (Command/Indicate) channel in GCI byte 4 is used solely to access the Activation Control Register and the Activation Indication Register in the TP3410. A complete description of these registers is found in Section 11, including the coding of the 4-bit messages. Unlike the Microwire Mode of the device, however, the contents of these 2 registers are transferred repeatedly in the C/I channel, once per GCI frame. A change in transmit message is originated by a change in the Activation Indication Register, while a change in received message is verified in 2 consecutive GCI frames before updating the Activation Control Register and taking the appropriate action. TL/H/9151 – 16 Note 1: As an output (GCI Master) FSa is high for 8-bit intervals (16 BCLK cycles). As an input (GCI Slave) FSa must be high for t 1 BCLK cycle. Note 2: The FSb output is provided only in GCI Master Mode. FIGURE 7. GCI Frame Structure is an Example of Multiplex Mode with BCLK e 4.096 MHz TL/H/9151 – 27 FIGURE 8. GCI Monitor Channel and E and A Bit Protocol 14 Functional Description (Continued) TABLE II. Command Registers Byte 1 (Register Address) Function Byte 2 (Data) 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 No Operation (NOP) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Write OPR Readback OPR 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 1 CIE X EIE X FIE X OB1 X OB0 X OC1 X OC0 X 0 X Write CR1 Readback CR1 0 0 0 0 1 1 0 0 0 0 0 0 1 1 0 1 FF1 X FF0 X CK2 X CK1 X CK0 X DDM CMS BEX X X X Write CR2 Readback CR2 0 0 0 0 1 1 0 0 0 0 1 1 0 0 0 1 SSS X NTS X DMO X DEN X DD X BP1 X BP2 X 0 X Write CR3 Readback CR3 0 0 0 0 1 1 0 0 0 0 1 1 1 1 0 1 LB1 X LB2 X LBD X DB1 X DB2 X DBD X TLB X 0 X Write CR4 Readback CR4 0 0 0 0 1 1 0 0 1 1 1 1 0 0 0 1 SH9 AACT X X WS X 333 Hz X saif X TFB0 RFS X X Write TXB1 TSA Readback TXB1 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 1 0 X 0 X TS5 X TS4 X TS3 X TS2 X TS1 X TS0 X Write TXB2 TSA Readback TXB2 0 0 0 0 1 1 1 1 0 0 0 0 1 1 0 1 0 X 0 X TS5 X TS4 X TS3 X TS2 X TS1 X TS0 X Write RXB1 TSA Readback RXB1 0 0 0 0 1 1 1 1 0 0 1 1 0 0 0 1 EB1 X ED X TS5 X TS4 X TS3 X TS2 X TS1 X TS0 X Write RXB2 TSA Readback RXB2 0 0 0 0 1 1 1 1 0 0 1 1 1 1 0 1 EB2 X 0 X TS5 X TS4 X TS3 X TS2 X TS1 X TS0 X Write TXD Readback TXD 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 1 DX5 X DX4 X DX3 X DX2 X DX1 X DX0 X SX1 X SX0 X Write RXD Readback RXD 0 0 0 0 1 1 1 1 1 1 0 0 1 1 0 1 DR5 X DR4 X DR3 X DR2 X DR1 X DR0 X SR1 X SR0 X Write TXM4 0 1 0 0 0 0 0 0 ACT M42 M43 M44 M45 M46 M47 M48 Write TXM56 0 1 0 0 0 0 1 0 0 0 LEC M51 M61 M52 TFB CTC LFS X Write ACT Register 0 1 0 0 0 1 0 0 0 0 0 0 C4 C3 C2 C1 Write ECT1 Read BEC1 0 0 1 1 0 0 0 0 0 0 1 1 1 1 0 1 O7 X O6 X O5 X O4 X O3 X O2 X O1 X O0 X Write TX EOC Register 0 1 0 1 ea1 ea2 ea3 dm ei1 ei2 ei3 ei4 ei5 ei6 ei7 ei8 Note 1: Bit 7 of byte 1 is always the first bit clocked into the device. Note 2: In the Tx EOC Register: ea1 e the msb of the EOC destination address; ea2 e bit 2 of the EOC destination address; ea3 e the lsb of the EOC destination address; dm e the EOC data/message mode indicator. Note 3: X e don’t care (it is recommended that these bits be set e 0). 15 Functional Description (Continued) TABLE III. Status Registers Byte 1 (Register Address) Function 7 6 5 4 Byte 2 (Data) 3 2 1 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 READABLE CONFIGURATION REGISTERS Default (No Change on a Write Cycle) OPR Contents CR1 Contents CR2 Contents CR3 Contents CR4 Contents TXB1 Contents TXB2 Contents RXB1 Contents RXB2 Contents TXD Contents RXD Contents BEC1 (Note 2) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 1 0 0 0 0 1 1 0 0 0 1 1 1 0 0 1 1 0 0 1 0 1 0 1 0 0 1 0 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 CIE EIE FIE OB1 FF1 FF0 CK2 CK1 SSS NTS DMO DEN LB1 LB2 LBD DB1 SH9 AACT WS 333 Hz 0 0 TS5 TS4 0 0 TS5 TS4 EB1 ED TS5 TS4 EB2 0 TS5 TS4 DX5 DX4 DX3 DX2 DR5 DR4 DR3 DR2 ec7 ec6 ec5 ec4 OB0 OC1 OC0 CK0 DDM CMS DD BP1 BP2 DB2 DBD TLB saif TFB0 RFS TS3 TS2 TS1 TS3 TS2 TS1 TS3 TS2 TS1 TS3 TS2 TS1 DX1 DX0 SX1 DR1 DR0 SR1 ec3 ec2 ec1 0 BEX 0 0 LFS TS0 TS0 TS0 TS0 SX0 SR0 ec0 REGISTERS WHICH GENERATE A MICROWIRE INTERRUPT OR GCI MONITOR CHANNEL MESSAGE (Note 4) RXM4 RXM56 Spare Bits ACT Indication Reg BEC1 (Note 2) RX EOC Register (Note 3) 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 ea1 0 0 1 1 ea2 0 1 0 1 ea3 0 0 0 0 dm M41 0 0 ec7 ei1 M42 ES2 0 ec6 ei2 M43 ES1 0 ec5 ei3 M44 M51 0 ec4 ei4 M45 M61 C4 ec3 ei5 M46 M52 C3 ec2 ei6 Note 1: Bit 7 of byte 1 is always the first bit clocked into the device. Note 2: BEC1 may be polled, via the appropriate read command (see Table II), at any time to read the current error count. Note 3: In the Rx EOC Register: ea1 e the msb of the EOC destination address; ea2 e bit 2 of the EOC destination address; ea3 e the lsb of the EOC destination address; dm e the EOC data/message mode indicator. Note 4: Changes in contents of these registers are queued on a stack which generates interrupts or messages in the following priority order: 1. 2. 3. 4. 5. 6. Register Readback request. ACT Indication Register (Microwire only). RXM4 Register. RX EOC Register. RXM56 Spare Bits Register. BEC1 Register. 16 M47 RFB C2 ec1 ei7 M48 NEB C1 ec0 ei8 Functional Description (Continued) DDM: Delayed Data Mode Select 9.0 COMMAND REGISTER FUNCTIONS All addressing and bit-level functions are the same for both the Microwire and GCI Monitor Channels, except where noted. Register addresses are listed in Table II. An asterisk * indicates the Power-on Reset state of each function. The device modes and Transmit M bits should be programmed while the device is powered down. For Microwire mode, see Section 6.1: FS Relationship to Data. In GCI Mode or Format 4 this bit has no effect. *DDM e 0 for non-delayed data mode (see Figure 11 ). DDM e 1 for delayed data mode (see Figure 12 ). CMS: DSI Clock Master/Slave Select In Microwire Mode (MW e 1): CMS e 0 for DSI Slave; may be used in either LT or NT Modes CMS e 1 for DSI Master; may be used in either LT or NT Modes, but when in LT Mode, must also send XÊ 1840. See the TP3410 User’s Manual AN-913 Section 4.5 for details. In GCI Mode (MW e 0) this bit has no effect; the MO pin selects GCI Master or Slave. 9.1 Writing to Command Registers A command may be written to a register to modify its contents by setting byte 1 bit 0 e 0. Registers CR1, 2, 3, OPR and the Time-Slot Assignment registers may also be readback to verify the contents by addressing each register with byte 1 bit 0 e 1. In Microwire Mode, if the device has no data waiting to be read during a command cycle it will return XÊ 0000 (No Change). BEX: B Channel Exchange This command enables the two B channels to be exchanged as the data passes through the device between the Digital Interface and the Line in both directions. It should not be used if any loopback is selected in the device. *BEX e 0 for B channels mapped direct, B1 to B1 and B2 to B2. BEX e 1 for B channels exchanged, B1 to B2 and B2 to B1. 9.2 Reading Back Command Registers for Verification To read back the current state of one of the write-able registers, the appropriate readback command must first be loaded in via the control channel; this will cause an interrupt to be sent to the interrupt stack. In Microwire mode the interrupt must be serviced by a read cycle, in which the command should be a NOP (or a new command). In this cycle the previously addressed register is read back, with byte 1 bit 0 e 1. In GCI mode, the interrupt stack generates an autonomous one-way message in the Monitor Channel. If any other interrupt conditions should occur during the readback command cycle, the readback result will be queued at the bottom of the stack, and will not generate its interrupt or message until all other interrupts are cleared. 9.4 Configuration Register CR2: Device Modes Byte 2 5 4 3 2 1 0 FF1 FF0 CK2 CK1 CK0 DDM CMS BEX FF1, FF0: Digital System Interface Frame Format Selection These bits are effective in Microwire Mode only (MW e 1). They select the Digital Interface format as described in Section 6. FF1 FF0 *1 2 3 4 0 0 1 1 0 1 0 1 CK1 CK0 BCLK Frequency: 0 0 0 0 1 0 0 1 1 0 0 1 0 1 0 *256 kHz Master 512 kHz Master 1536 kHz Master 2048 kHz Master 2560 kHz Master 3 2 1 0 NTS DMO DEN DD BP1 BP2 0 DEN: D Channel Port Select *When DEN e 0, the D channel port is disabled and the D bits are transferred on the Br and Bx pins, clocked by BCLK. The Dx pin must also be tied to GND for correct operation. When DEN e 1, the D channel port is enabled; D bits are transferred on the Dr and Dx pins in a mode selected by the DMO bit, see Section 6.3. DMO: D Channel Transfer Mode Select This bit is significant only when the D channel port is selected (DEN bit e 1). When DMO e 1, D channel data is shifted in and out on Dx and Dr pins in a continuous mode at 16 kbit/s on the falling and rising edges of DCLK respectively, see Figure 4 . When DMO e 0, D channel data is shifted in and out on Dx and Dr pins in a burst mode at the BCLK frequency when the assigned time-slots are active, see Figure 5 . CK0 – CK2: Digital Interface Clock Select In Microwire Mode only, and if DSI Master is selected (CMS e 1), CK0–CK2 bits select from a choice of 5 frequencies for the BCLK output. (In GCI Mode, these bits have no effect.) The frequency of 256 kHz is not valid with Format 4. CK2 4 SSS NTS: NT or LT Select *NTS e 0 for LT Mode. NTS e 1 for NT Mode. *CR1 is set to XÊ 00 at Power-On Reset. Format 5 SSS: Superframe Synchronization Select This bit is effective in LT mode only; in NT mode the SFS pin is an output. When SSS e 0, SFS is an input which synchronizes the transmit superframe counter on the line. When SSS e 1, SFS is an output superframe marker pulse. Byte 2 6 6 *CR2 is set to XÊ 00 at Power-On Reset. 9.3 Configuration Register CR1: Digital Interface 7 7 DD: 2B a D Data Disabling *When DD e 0, 2B a D channel transfer is enabled as soon as the line is completely synchronized. When DD e 1, B and D channel transfer is inhibited. The data transmitted to line is preset to send scrambled 1’s with the device in NT mode or scrambled 0’s if the device is in LT 17 Functional Description (Continued) mode, and the 2B a D slots at the receive digital interface port(s) are in the high impedance state. SH9: Software H9 Control Bit *SH9 e 0 (default state) In NT mode, while SH9 e 0, a rev 3.x device in state H6, H7 or H8, H11 will enter the H9 state in response to receiving ‘‘dea e 0’’ for 3 consecutive superframes and then exit after 60 ms (to prevent a ‘‘hang up condition’’) to H12. With SH9 e 1, a TP3410 Rev 3.3 device in state H6, H7 or H8, H11 will generate a DP interrupt when it receives the ‘‘dea e 0’’ bit but is prevented from transitioning to device state H9. The device will still deactivate in response to loss of signal. Deactivating in this manner will however cause the NT mode device to perform a cold start only on subsequent activation attempts. The WS bit may be set e 1 for the device to attempt a warm start. BP1: Not Used This bit is not used and should always be set to zero. *BP1 e 0 BP2: Activation Breakpoint This bit is effective only in LT mode. It provides for the startup sequence to be either automatically controlled by the TP3410, or for the external controller to be able to halt the sequence at J7. The controller can complete start-up by sending ‘‘AC’’ to the ACT register (XÊ 440C). For more information, see Section 11.0, Activation/Deactivation. *BP2 e 0 for Breakpoint disabled. BP2 e 1 for Breakpoint enabled. AACT: Activation Control Bit *AACT e 0 (default state) 9.5 Configuration Register CR3: Loopbacks AACT e 1 enables auto-activation in either LT or NT modes. AACT e 0 disables it (default state) and the device behaves normally. Auto-activation can be used in applications such as Linecard, to allow the device to respond to an incoming 10 kHz wake-up tone (LSD) by powering itself up (PUP) and starting the activation procedure (AR) within the device. Byte 2 7 6 5 4 3 2 1 0 LB1 LB2 LBD DB1 DB2 DBD TLB 0 *CR3 is set to XÊ 00 at Power-On Reset. Line Loopbacks Select: LB1, LB2, LBD LB1, LB2, LBD bits, when set e 1, loopback each individual B1, B2, or D channel respectively from the line receive input to the line transmit output. They may be set separately or together. Each loopback is operated near the Bx and Br digital interface pins (or Dx and Dr if the D port is selected). These loopbacks may be either transparent, that is data received from the line is also passed on to the digital interface, or non-transparent, in which case the selected channel bits on the digital interface are in the high impedance state; transparency is controlled by the TLB bit. WS: Warm Start *WS e 0 (default state) If this bit is set e 1, a Rev 3.3 device will attempt Warm Start activation after a deactivation. This function should only be necessary where Warm Start is preferred but SH9 e 1 is required. 333 Hz: Maintenance Test Tone *333 Hz e 0 (default state) 333 Hz e 1 enables 333 Hz tone for Maintenance test modes (Bellcore requirement). 333 Hz e 0 disables it. This test tone is to be used in power up (after PUP) state but not activated. Example of use: Write PUP, XÊ 2C1F to enable 333 Hz test tone, XÊ 2C0F to disable 333 Hz tone. Digital Loopbacks Select: DB1, DB2, DBD DB1, DB2 and DBD bits, when set e 1, turn each individual B1, B2, or D channel respectively from the Bx input to the Br output (or Dx and Dr if the D port is selected). They may be set separately or together. Each loopback is operated near the digital interface pins; if Format 3 is selected there is no restriction on the time-slots selected for each direction. These loopbacks may be either transparent, that is data received from the Bx or Dx input is also transmitted to the line, or non-transparent, in which case the selected channel bits to the scrambler are forced low in LT mode or high in NT mode; transparency is controlled by the TLB bit. saif: Select Analog Interface *saif e 1 (default state) saif e 1 indicates operation with the standard line interface that is compatible with Rev. 2.x devices. saif e 0 indicates use of the alternative line interface circuit with 0X on the line-side of the transformer. This circuit can provide benefit for linecard applications where line powering of remote NT1s and repeaters is required. Example of use: Write XÊ 2C0F for standard line interface and XÊ 2C07 for alternative line interface. TLB: Transparent Loop-Back Enabling *TLB e 0 for non-transparent loopbacks (B1, B2 or D channel). TLB e 1 for transparent loopbacks. 9.6 Configuration Register CR4: Device Control A new configuration register (CR4) has been added to the Rev. 3 TP3410 device to allow control of new features. Please also see TP3410 Users Manual AN-913. Address XÊ 2C. TFB0 *TFB0 e 1 (default state) TFB0 e 0 forces transmit febe to 0 continuously for test purposes. TFB0 e 1 allows normal operation controlled by LFS and RFS. Note that this function was controlled by the TFB bit in TXM56 register in Rev. 2.x devices. The TFB bit in TXM56 bit is now (Rev. 3.x) active for one superframe only: if set to 0 by software, a superframe will transmit febe e 0, and then the TFB will be reset to 1 by the device. The software does not need to set it to 1. Byte 2 7 6 5 4 3 2 1 0 SH9 AACT WS 333 Hz saif TFB0 RFS LFS *CR4 is set to XÊ 0F at Power-On Reset. 18 Functional Description (Continued) B Channels Time-Slot Assignment: TS5 – TS0 RFS: Remote Febe Select *RFS e 1 (default state) The state of the outgoing bit is computed based on the state of the TFB (bit 1) in TXM56 register. The TFB blt is set e 0 by the software to allow a febe blt from an adjacent DSL to be forwarded to the next section in the next superframe. This bit is self resetting (to 1) in Rev. 3.x devices. This is a change from the Rev. 2.x devices. If RFS e 0, then the outgoing febe does not depend on the state of the TFB blt in TXM56 register. The TS5 – TS0 bits define the binary number of the time-slot when the B channel selected is shifted to or from the Bx and Br pins; time-slots are numbered from 0 to 63. New time-slot assignments become effective only at the beginning of a frame. B1 and D Channel Enables: EB1; ED *EB1 e 0 to disable the B1 channel; B1 is high-impedance at Br. EB1 e 1 to enable the B1 channel (must also set DD e 0 in CR2). *ED e 0 to disable the D channel; D is high-impedance at Br or Dr. ED e 1 to enable the D channel (must also set DD e 0 in CR2). LFS: Local Febe Select *LFS e 1 (default state) The state of the outgoing febe bit is computed using the incoming nebe blt. If LFS e 0, the outgoing febe is not dependent on the incoming nebe. Example of use: A flexible control of the outgoing febe bit is provided to support the Segmented and Path Performance Monitoring recommendations in Bellcore TR 397. For Rev. 2.8 type operation, set RFS e 1, LFS e 1 and TFB0 e 1. This setting will cause the transmit febe to be computed as OR of the incoming nebe blt and the state of the TFB bit in TXM56 (representing the adjacent section febe to be forwarded). B2 Channel Enable: EB2 EB2 e 0 to disable the B2 channel; B2 is high-impedance at Br. EB2 e 1 to enable the B2 channel (must also set DD e 0 in CR2). 9.8 Configuration Register TXD: Transmit D Channel TSA This register is effective only when Format 3 is selected. D channel TSA may be used when the D channel is accessed either via the Bx/Br or Dx/Dr pins, but the D channel port must be clocked with BCLK (DMO e 0 in CR2). 9.7 Configuration Registers TXB1, TXB2, RXB1, RXB2: B Channel TSA These registers are effective only when Format 3 is selected. TXB1 assigns the Transmit time slot for the B1 channel. TXB2 assigns the Transmit time slot for the B2 channel. RXB1 assigns the Receive time slot for the B1 channel. RXB2 assigns the Receive time slot for the B2 channel. Byte 2 5 4 3 2 1 0 0 0 TS5 TS4 TS3 TS2 TS1 TS0 At Power-On Reset this register is initialized to XÊ 00. Register TXB2 Byte 2 7 6 5 4 3 2 1 0 0 0 TS5 TS4 TS3 TS2 TS1 TS0 At Power-On Reset this register is initialized to XÊ 01. Byte 2 6 5 4 3 2 1 0 EB1 ED TS5 TS4 TS3 TS2 TS1 TS0 At Power-On Reset this register is initialized to XÊ 00. Byte 2 6 5 4 3 2 1 0 EB2 0 TS5 TS4 TS3 TS2 TS1 TS0 3 2 1 0 DX5 DX4 DX3 DX2 DX1 DX0 SX1 SX0 SX1 SX0 *0 0 1 1 0 1 0 1 Bit Positions within Time-Slot 1, 2 3, 4 5, 6 7, 8 9.9 Configuration Register RXD: Receive D Channel TSA This register is effective only when Format 3 is selected. D channel TSA may be used when the D channel is accessed either via the Bx/Br or Dx/Dr pins, but the D channel port must be selected in the burst mode (DMO e 0 in CR2). Register RXB2 7 4 Sub-Slot Register RXB1 7 5 Transmit D Channel Time-Slot Assignment Select: DX5 – DX0, SX1 – SX0 DX5 – DX0 bits define the binary number of the 8-bit wide time-slot, where time-slots are numbered from 0 to 63. Within this selected time-slot, the SX1 and SX0 bits define the 2bit wide sub-slot for the 2 D channel bits. Sub-slots are numbered 0 to 3, as shown in Figures 5, 11 and 12 and the following table. New time-slot and sub-slot assignments become effective only at the beginning of a frame. Byte 2 6 6 *At Power-On Reset this register is initialized to XÊ 08. Register TXB1 7 7 *At Power-On Reset this register is initialized to XÊ 01. 19 Functional Description (Continued) Receive Overhead Bits Interrupt Enable: 0B1, 0B0 Byte 2 7 6 5 4 3 2 1 0 DR5 DR4 DR3 DR2 DR1 DR0 SR1 SR0 These bits determine how many consecutive superframes must be received with the same new data in any of the overhead bit positions M41 – M48, M51, M52 and/or M61 before an Interrupt(s) is generated for the RXM4 and/or RXM56 Register, as appropriate. Note that validation checking of the ‘‘act’’ and ‘‘dea’’ bits during activation/deactivation is not affected by OB1/OB0. *At Power-On Reset this register is initialized to XÊ 08. Receive D Channel Time-Slot Assignment Select: DR5 – DR0, SR1 – SR0 DR5 – DR0 bits define the binary number of the 8-bit wide time-slot, where the time-slots are numbered from 0 to 63. Within this selected time-slot, the SR1 and SR0 bits define the binary number of the 2 D channel bits. Sub-slots are numbered 0 to 3, as shown in Figure 12 and the following table. New time-slot and sub-slot assignments become effective only at the beginning of a frame. Sub-Slot SR1 SR0 Bit Positions within Time-Slot *0 0 1 1 0 1 0 1 1, 2 3, 4 5, 6 7, 8 OB1 *0 0 OB0 0 1 1 0 1 1 Interrupt every superframe (no checking). Interrupt if any bit changed from previous superframe. 2 consecutive times for same new bit(s) before Interrupt. 3 consecutive times for same new bit(s) before Interrupt. Receive Embedded Operations Channel Interrupt Enable: OC1, OC0 These bits determine how many consecutive half-superframes must be received with the same new address or data in the Embedded Operations Channel before an Interrupt is generated for the RX EOC Register. 9.10 Configuration Register OPR: Overhead Bit Processing This register controls the enabling/disabling of conditions which are sent to the Interrupt Stack (see 10.1) as a result of new data in the RXM4 and RXM56 Overhead Bits Registers, and the number of consecutive times a new bit or message is received before being validated. Flexibility is therefore provided to use hardware, external firmware routines or a combination of both for validation. 7 6 5 4 3 2 1 0 EIE FIE OB1 OB0 OC1 OC0 0 OC0 0 0 1 1 0 1 1 Interrupt every received eoc message (no checking). Interrupt every received eoc message which differs from previous message. 2 consecutive times for same new message before Interrupt. 3 consecutive times for same new message before Interrupt. 9.11 Transmit M4 Channel Register TXM4 (Write Only) When the line is superframe synchronized, the device transmits the contents of this register to the line in the M4 overhead bit field once per superframe. Byte 2 CIE OC1 *0 Byte 2 *At Power-On Reset this register is initialized to XÊ 00. Near-End CRC Interrupt Enable: CIE CIE *0 1 No Interrupt if near-end crc error (Block Error Counters still count). RXM56 Status Register Interrupt is generated, with NEB e 0, each superframe in which the locallygenerated crc result does not match the crc in the received superframe. 1 5 4 3 2 1 0 ACT M42 M43 M44 M45 M46 M47 M48 ACT Bit The ACT bit in the TXM4 register does not normally control the ‘‘act’’ bit in the M4 word transmitted to the line (see Table I). That ‘‘act ’’ bit is generated automatically within the device and can be controlled through the Activation Control Register (see Table I and Section 11.0, Activation/Deactivation). In normal operation the ACT bit in the TXM4 register is ignored. No Interrupt or Monitor channel message from Block Error Counters. Block Error Counter Interrupts enabled. M42 – M48 Bits As shown in the Frame Formats in Table I, the functions of these bits depend on the mode of the device. They should be programmed as appropriate prior to an Activation Request, with the exception of the M42 bit in LT Mode. This is the dea bit, which is automatically controlled by the device in response to AR and DR commands; the M42 bit in this register is normally ignored in LT mode. febe Bit Interrupt Enable: FIE FIE *0 1 6 At Power-On Reset, and each time the device is Deactivated (or an Activation attempt fails), this register is initialized to XÊ 7F. Block Error Counter Interrupt Enable: EIE EIE *0 7 No Interrupt if febe e 0 received (BEC1 still counts). RXM56 Status Register Interrupt is generated, with RFB e 0, each superframe in which febe e 0 is received. 20 Functional Description (Continued) At Power-On Reset this register is initialized to XÊ FF. 9.12 Transmit M5/M6 Spare Bits Register TXM56 (Write Only) This register may be loaded with any value, which is then used to preset the Block Error Counter BEC1. BEC1 decrements 1 count for each block error. When the counter value reaches X’00 the BEC1 interrupt is sent to the stack (if enabled by EIE e 1 in the OPR reg.). Byte 2 7 6 5 4 3 2 1 0 0 0 LEC M51 M61 M52 TFB CTC 10.0 STATUS REGISTERS All Status Register addressing and bit-level functions are the same for both the Microwire and GCI Monitor Channels, except where noted. Register addresses are listed in Table III. At Power-On Reset, and each time the device is Deactivated (or an Activation attempt fails), this register is initialized to XÊ 1E. M51, M61, M52 The M51, M61, and M52 bits in this register control the appropriate overhead bits transmitted to the line. They should be set e 1 but may be subject to future standardization. 10.1 Reading Status Registers In Response To An Interrupt Conditions occurring in the device which generate Microwire interrupts or GCI Monitor Channel messages are queued in a stack, with a pre-defined priority, see Table III. In Microwire mode the INT pin is pulled low and a NOP command should be loaded into the Microwire during the read cycle (or a valid command may be used to modify a register if required). In GCI mode, the interrupt stack generates an autonomous one-way message in the Monitor Channel. Transmit febe Bit Control: TFB This bit should normally be set e 1. The febe bit transmitted in the M62 bit position is then automatically controlled by the device; febe is the far-end block error bit which is normally high, and set low when a crc (cyclic redundancy check) error has been detected in the previously received superframe. For test purposes, however, febe may be forced continuously low by setting TFB e 0. 10.2 Receive EOC Register This register is significant only when the EOC channel processing is enabled (see register OPR). Corrupt Transmit crc: CTC To allow the normal calculation of the crc for the transmitted data to the line, set CTC e 0. In order to send a corrupted crc for test purposes, set CTC e 1, which causes the crc result to be continuously inverted prior to transmission. Byte 1 3 Latched External Control: LEC This bit directly controls the LEC output pin, in GCI mode. Byte 1 2 1 7 6 5 4 3 2 1 0 ea1 ea2 ea3 dm ei1 ei2 ei3 ei4 ei5 ei6 ei7 ei8 At Power-On Reset, and each time the device is Deactivated (or an Activation attempt fails), this register is initialized to XÊ FF. The Tx EOC Register contains 12 bits which correspond to the 12 bits of a message in the Embedded Operations Channel, see Table I: ea1, ea2 and ea3 correspond to the 3 EOC destination address bits, eoca1, eoca2, eoca3; the dm bit indicates if the information is in message mode or data mode (data if dm e 0, message if dm e 1); ei1 – ei8 correspond to the 8 eoc data bits, eoci1–eoci8. Only bits 7–4 of byte 1 are used to address this register, as shown in Table II. 6 5 4 3 2 1 0 O6 O5 O4 O3 O2 O1 O0 6 5 4 3 2 1 0 Byte 2 Byte 2 7 7 10.3 RXM4: Receive M4 Overhead Bits Register This register is significant only when the Spare Bit processing is enabled (see register OPR). 9.14 Error Counter Threshold Register: ECT1 O7 Byte 2 0 The RX EOC Register contains 12 bits which correspond to the 12 bits of a message in the Embedded Operations Channel, see Table I: ea1, ea2 and ea3 correspond to the 3 EOC destination address bits, eoca1, eoca2, eoca3; the dm bit indicates if the information is in message mode or data mode; ei1 – ei8 correspond to the 8 eoc data bits, eoci1 – eoci8. Only bits 7 – 4 of byte 1 are used to address this register, as shown in Table II. When the line is fully superframe synchronized, the device extracts these 12 bits from the channel every half superframe. Each EOC message is validated according to the mode selected in Register OPR, and if a message contains a new address or new data, the Rx EOC Register is sent to the Control Interface, through an interrupt cycle request. If one of the defined coded commands is received, e.g., Send Corrupted CRC, then the appropriate Command Register instruction must be written to the device to select that function. Byte 2 0 1 ea1 ea2 ea3 dm ei1 ei2 ei3 ei4 ei5 ei6 ei7 ei8 9.13 Transmit EOC Register (Write Only) When the line is fully superframe synchronized, the device continuously sends the contents of this register to the line twice per superframe in the EOC channel field. The register contents are loaded into the line transmit register every half superframe. 3 2 21 7 6 5 4 3 2 1 0 M41 M42 M43 M44 M45 M46 M47 M48 Functional Description (Continued) The RXM4 Register consists of 8 bits, which correspond to the M4 overhead bit position in each of the 8 Basic Frames of a superframe. When the line is fully superframe synchronized, the device extracts from the M channel these 8 bits every superframe. At the end of each superframe, the register content is sent to the Interrupt stack, in accordance with the validation mode selected in Register OPR. M41, and M42 in NT mode, are only provided via this register while the line is fully activated (after AI). During the activation and deactivation sequences the ‘‘act’’ and ‘‘dea’’ bits are processed automatically, see the Activation Control section. 11.1 Activation Control Register Byte 2 5 4 3 2 1 0 0 ES2 ES1 M51 M61 M52 RFB NEB Data in this register consists of 7 bits: M51, M52, M61 and RFB (RFB e receive febe, the far-end block-error indicator from the M62 bit position), all of which correspond to the overhead bits received once per superframe, plus NEB, which is an internally generated bit indicating a near-end block-error. Bits ES1 and ES2 are available in GCI mode only. When the line is fully superframe synchronized, the device loads the register with the received bits M51, M52, M61 and febe every superframe; in GCI mode the ES1 and ES2 input pins are also sampled. The 12-bit crc received from the far-end is also compared at the end of the superframe with the crc previously calculated by the device. If an error is detected, the febe bit in the transmit direction is automatically forced low in the next superframe and the NEB bit in this register is set low also. The register content is sent to the Interrupt stack at the end of each superframe. 5 4 3 2 1 0 ec7 ec6 ec5 ec4 ec3 ec2 ec1 ec0 3 2 1 0 0 0 0 0 C4 C3 C2 C1 LT MODE NT MODE C4 C3 C2 C1 IND COM IND 0 0 0 0 TIM* PUP/DR DP/LSD COM PUP 0 0 0 1 X RES X RES 0 1 0 0 EI FA0 EI SEI 0 1 0 1 X PDN X PDN 0 1 1 0 SYNC X X X 1 0 0 0 AP AR AP AR 1 1 0 0 AI AC AI AC 1 1 1 1 DI DC* DI DC* 11.2 Activation Commands PUP This command powers up the device and starts the oscillator. PUP/DR When the TP3410 is in the power-down state, this command powers up the device and starts the oscillator. In LT mode only, when the device is activated, this code is a Deactivation Request, which forces the device through the specified deactivation sequence by setting ‘‘dea’’ e 0 in 4 consecutive superframes before ceasing transmission. PDN This power-down command immediately forces the device to a low power state, without sequencing through any of the de-activation states. It should normally only be used after the TP3410 has been put in a known state, e.g., after a DI status indication has been reported. AR Activation Request, which is used after first powering up the device to initiate the specified Activation sequence. AC Activation Complete, which may be used to set ‘‘act’’ e 1 in each direction at the completion of activation. In LT mode this is only necessary if Breakpoint 2 is enabled (in Register CR2); in NT mode this is normally required when synchronization on the S/T Interface is confirmed by detection of INFO3. RES RES is the reset command which resets the activation sequencer to the Receive Reset state and resets the DSP coefficients in preparation for a cold-start. This command should be used only in the event of a failed activation attempt (expiry of T4 or T5); it does not affect the Command Registers. Byte 2 6 4 Note 1: X indicates reserved codes which should not be used. 10.5 Block Error Counter: BEC1 7 5 CODE Byte 2 6 6 At Power-On Reset, and each time the device is Deactivated (or an Activation attempt fails), this register is initialized to XÊ 0F. Activation commands and status indicators are coded as follows: 10.4 RXM56: Receive M5/M6 Spare Bits Status Register This register is significant only when the Spare Bit processing is enabled (see register OPR). 7 7 At Power-On Reset this counter is preset e XÊ FF. BEC1 This 8-bit counter is decremented by 1, starting from the value in the ECT1 register, if either febe e 0 or nebe e 0 in the same superframe. When the counter reaches X’00 (and if the Interrupt is enabled by means of the EIE bit in Register OPR), an interrupt is queued in the interrupt stack. The counter may also be read at any time; the count will be the ECT1 value minus the number of errors since the last read of this register. Reading the counter, or when the counter decrements to XÊ 00, causes the count to be reset to the ECT1 value. 11.0 ACTIVATION/DEACTIVATION A common coding table is used for the commands in the Activation Control Register and the status indicators in the Activation Indication Register. They control the Power-Up/ Down, Activation and Deactivation states of the device. When the device is in GCI Mode, the 4 significant bits in these registers (3 –0) continuously report their current contents in the C/I channel. In Microwire Mode the registers are addressed with a normal 16-bit cycle as shown in Table II. 22 Functional Description (Continued) FA0 SEI DC* DI This command may be used on a fully activated line to force the transmit ‘‘act’’ bit e 0, to indicate loss or denial of 2B a D transparency to the NT (LT state J7). To revert back to sending ‘‘act’’ e 1 use the AC command (with BP2 e 1). S-Interface Error Indication, which should only be used in an NT-1 when loss of received signal is detected (i.e., INFO 0). This command forces the upstream ‘‘act’’ bit (M41) e 0. Deactivation Confirmation. This command may be used as an alternative to PDN, to power-down the device in response to a DI indication. It should not be used prior to the DI indication. TIM 11.5 Cold Start and Warm Start When power is first applied to the device, the first AR command will always initiate a cold-start sequence, which may take up to 15 seconds for complete activation. If the device is subsequently deactivated using the correct procedure, and provided power is maintained uninterrupted in either the power-up or power-down state, the next AR instruction automatically sequences through the warm-start procedure, which normally achieves complete loop activation within 300 ms. The device includes the specified timers of 15s, 480 ms and 40 ms at the appropriate phases of the activation and deactivation sequences. For applications requiring a default timeout other than 15s the internal timer can be disabled to allow an external timer to be used. 11.3 Activation Indication Register: (READ ONLY) Byte 2 7 6 5 4 3 2 1 0 0 0 0 0 C4 C3 C2 C1 The Deactivated Indication, which confirms that the loop has been deactivated by means of a Deactivate Request at the LT, and has entered the RESET state. DI* is effective in GCI mode only. In GCI mode only, TIM is an acknowledgment when the device is in the power-down state and receives a PUP command. Activation Indicators are coded the same as for the Activation Control Register. In Microwire mode only, at each activation status change the four significant bits in this register are sent to the Interrupt stack. If multiple interrupt conditions should arise simultaneously, this register has the highest priority and will be read first. 11.6 LT Mode Activation/Deactivation If activation is initiated by the downstream (NT mode) end with the device either powered up or down, an AP Interrupt condition will be generated on detection of the 10 kHz ‘‘wake-up’’ tone. The Activation Indication Register will show this condition and, if the device is powered down, the LSD pin will be pulled low. Prior to initiating activation all registers must be programmed appropriately and the device must then be powered up. The use of the commands and status indicators is the same whether activation is initiated locally or from the remote end. An AR command is required to enable the device to proceed with the activation sequence. An internal 15s default timer is also started (in North America the timer value should be 15 seconds if a single loop section is being activated). Please see TP3410 User’s Manual for additional information on activation and deactivation. The sequence continues automatically until superframe synchronization is acquired on the SN3 signal received from the NT. At this point the ‘‘act’’ bit is set e 1 in the downstream direction, and the AI Interrupt is generated in the Activation Indication Register. The loop is then fully activated, with all channels in the data stream available for use. If activation is not successfully completed before expiry of the 15s timer, the device generates an EI followed by a DI fault indication and ensures that the Activation Sequencer returns to the Full Reset state (J10 to J1) prior to any reattempt to activate. For additional control over the activation sequence, a breakpoint state may be enabled at the LT. BP2 will halt the sequence when the loop is fully synchronized, receiving SN3, but the ‘‘act’’ bit is held e 0; this state prevents the S/T Interface from becoming fully activated (the NT1 will maintain INFO2 towards the TEs). An AC command will release this state, allowing activation to be completed. The BP2 bit in Register CR2 controls the enabling of this breakpoint. 11.4 Activation Status Indicators DP/LSD When the TP3410 is deactivated, either powered up or powered down, the Line Signal Detector sets this indicator if it detects an incoming 10 kHz wake-up tone. If the device is powered down the LSD pin is also pulled low. In NT mode only, this code also functions as a Deactivation Pending indicator when ‘‘dea’’ e 0 is validated. SYNC In LT mode only this indicates when superframe sync is detected, and should be used to stop the external default timer. AP Activation Pending, which is used in NT mode to indicate when superframe sync has been acquired and the BCLK and FS outputs are synchronized to the received line signal. In LT mode, the Line Signal Detector sets this indicator if it detects an incoming 10 kHz wake-up tone. AI This Activation Indication code indicates that the loop is fully activated, (‘‘act’’ e 1 has been received), and the 2B a D channels are enabled for data transfer. In LT mode, however, if Breakpoint Ý2 is enabled via CR2, it is necessary to respond to AI with an AC command. This will cause the device to set ‘‘act’’ e 1 in the transmit frame and open the 2B a D channels for data transfer. EI Loss of frame synchronization will set this Error Indicator and inhibit the 2B a D channel data. If a received line signal can still be detected the device will attempt to recover synchronization for up to 480 ms; if this fails it will enter the RESET state and generate a DI. The EI indication is also generated on an activated line if the received ‘‘act’’ bit changes from 1 to 0, indicating loss of tranparency at the far-end. 23 quirements are met under all specified loop conditions. Deviations from these designs may result in sub-optimal performance or even total failure of the system to operate on some types of loops. The standare LIC (Figure 9) has the advantage of backwards compatibility with Rev. 2.x devices together with a generally lower component sensitivity. The TP3410 must be configured to select the chosen LIC. For the standard LIC, set saif e 1 in register CR4. This is the default configuration. The alternative LIC (Figure 10) does not use lineside surge limiting resistors and so has advantages where line powering is required. To configure the TP3410 for the alternative LIC, set saif e 0. Transformer parameters form a major part of the LIC. Two of the most important are: Turns Ratio: Chip side (primary): Line side (secondary) Functional Description (Continued) Deactivation is initiated by writing the DR command in the Activation Control Register, causing ‘‘dea’’ e 0 to be transmitted towards the NT. When the NT ceases to transmit, confirmation of deactivation is provided by a DI Status indicator. 11.7 NT Mode Activation/Deactivation If activation is initiated by the upstream (LT mode) end with the NT either powered up or down, a Line Signal Detect Interrupt will be generated on detection of the 10 kHz ‘‘wake-up’’ tone. The Activation Indication Register will show this condition and, if the device is powered down, the LSD pin will be pulled low. To proceed with the activation sequence, all registers must be programmed appropriately (see Note 1) and the device must then be powered up. The use of the commands and status indicators is the same whether activation is initiated locally or in response to the Line Signal Detect Interrupt. An AR command will enable the device to automatically proceed with the activation sequence. An internal 15s default timer is also started (in North America the timer value should be 15 seconds if a single DSL section is being activated). See TP3410 User’s Manual for additional information on activation and deactivation. The sequence continues until the NT acquires superframe synchronization on the SL2 signal received from the LT. At this point an AP Interrupt is generated and the device starts transmitting SN3 with ‘‘act’’ e 0. To complete activation, normally when the NT has detected INFO3 signals from a TE, the ‘‘act’’ bit must be set e 1 by writing the AC command to the Activation Control Register. An AI Status indication will finally be generated by the device when the loop is fully synchronized and receiving SL3 frames with ‘‘act’’ e 1; this is automatically validated 3 times regardless of the options selected in Register OPR. The loop is then fully activated, with all channels in the data stream available for use. If activation is not successfully completed before expiry of the 15s timer, the device generates an EI followed by a DI fault indication and ensures that the Activation Sequencer returns to the Full Reset state prior to any re-attempt to activate. Deactivation is normally initiated by the LT, which sets ‘‘dea’’ e 0 towards the NT. The TP3410 in NT mode will detect and validate this bit 3 times prior to setting the DP interrupt (regardless of the options selected in OPR). Transmission will cease when it is detected that the far-end signal has ceased, after which the device enters the Reset state and generates a DI Interrupt to indicate that deactivation is complete. e 1:1.5 Secondary inductance: LS e 27 mH g 5% at 1 kHz For more details on transformer specification and for a list of qualified vendors, see the TP3410 User’s Manual, AN-913. BOARD LAYOUT While the pins of the TP3410 are well protected against electrical misuse, it is recommended that the standard CMOS practice of applying GND to the device before any other connections are made should always be followed. In applications where the printed circuit card may be plugged into a hot socket with power and clocks already present, an extra long ground pin on the connector should be used. Great care must be taken in the layout of the printed circuit board in order to preserve the high transmission performance of the TP3410. To maximize performance do not use the philosophy of separating analog and digital grounds on the board. The 3 GND pins should be connected together as close as possible to the pins, and the 2 VCC pins should be strapped together. All ground connections to each device should meet at a common point as close as possible to the 3 GND pins in order to prevent the interaction of ground return currents flowing through a common bus impedance. A decoupling capacitor of 0.1 mF should be connected from this common point to the VCC pins. Taking care with the pcb layout in the following ways will also help prevent noise injection into the receiver front-end and maximize the transmission performance: 1. Keep the crystal oscillator components away from the receiver inputs and use a ground plane for shielding around these components. 2. Keep the connections between the device and the components on the Li g inputs short. 3. Keep the connections between the device and transformer short. Note 1: The M45 bit conveys an indication of whether the NT can support a warm-start procedure (the ‘‘cso’’ bit). Since the TP3410 automatically supports both cold and warm start, set ‘‘cso’’ e 0. Applications Information LINE INTERFACE CIRCUIT The transmission performance obtainable from a TP3410 U-interface is strongly dependent on the line interface circuit (LIC) design. Two designs, shown in Figures 9 and 10 , are recommended. They should be adhered to strictly. The channel response and insertion losses of these circuits have been carefully designed as an integral part of the overall signal processing system to ensure the performance re- ADDITIONAL INFORMATION For more in-depth information on a variety of applications, the TP3410 Users Manual, AN-913, is a comprehensive guide to the hardware and software required to meet the ANSI interface specification. 24 Applications Information (Continued) TL/H/9151 – 19 Note 1: 0.1% matching may be required to meet the longitudinal balance specification, depending on the Longitudinal impedance to ground of the line interface. The 15X and 1k resistors in the line interface circuit should be 1% tolerance, and the capacitors should be 10%. Note 2: An alternative circuit which removes the 24X surge-limiting resistors is shown in Figure 10 . Note 3: Only necessary in GCI Mode. Note 4: See AN-913 for further information about the line circuit. FIGURE 9. Typical Application in Microwire Mode TL/H/9151 – 20 Note 1: All resistors 1% tolerance, and capacitors 10%. Note 2: This circuit provides no surge current limiting for the transformer. Note 3: See AN-913 for further information about the line circuit. FIGURE 10. Alternative Interface Circuit 25 Absolute Maximum Ratings Storage Temperature Range If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. VCC to GND Voltage at Li, Lo Voltage at Any Digital Input b 65§ C to a 150§ C Current at Lo g 200 mA Current at Any Digital Output Lead Temperature (Soldering, 10 seconds) ESD (Human Body Model) J iJA (Package Number J28A) 7V VCC a 1V to GND b 1V VCC a 1V to GND b 1V g 50 mA 300§ C TBD 40§ C/W Electrical Characteristics Unless otherwise noted, limits printed in bold characters are electrical testing limits at VCC e 5.0V and TA e 25§ C. All other limits are design goals for VCC e 5.0V g 5% and TJ e 0§ C to 90§ C (refer to Application Note AN-336). This data sheet is still preliminary and parameter limits are not indicative of characterization data with respect to power supply or temperature variations. Please contact your National Semiconductor Sales Office for the most current product information. Symbol Parameter Limits Conditions Min Typ Units Max DIGITAL INTERFACES VIL Input Low Voltage All Digital Inputs VIH Input High Voltage All Digital Inputs 0.7 VILX Input Low Voltage MCLK/XTAL Input VIHX Input High Voltage MCLK/XTAL Input VOL Output Low Voltage Br, IO e 3.2 mA All Other Digital Outputs, IO e 1 mA VOH Output High Voltage Br, IO e 3.2 mA All Other Digital Outputs, IO e b1 mA All Outputs, IO e b100 mA II Input Current Any Digital Input, GND k VIN k VCC b 10 10 mA IOZ Output Current in High Impedance State (TRI-STATEÉ) Br, INT, LSD, CO, Dr GND k VOUT k VCC b 10 10 mA 2.2 V V 0.5 VCC b 0.5 V V 0.4 2.4 2.4 V V V V VCC b 0.5 LINE INTERFACES RLi Differential Input Resistance GND k Li a , Lib k VCC CLLo Load Capacitance Between Lo a and Lob Connected Externally VOS Differential Output Offset Voltage at Lo a , Lob 30 kX b 100 200 pF a 100 mV POWER DISSIPATION ICC0 Power Down Current All Outputs Open-Circuit 4 mA ICC1 Power Up Current Device Activated 65 mA g 3.5 Vpk TRANSMISSION PERFORMANCE Transmit Pulse Amplitude RL e 115X between Lo a and Lob (Note 2) Transmit Pulse Linearity Input Pulse Amplitude 36 Differential between Li a and Lib g4 60 dB g 800 mVpk Note 1: GND refers to GNDA, GNDD1 and GNDD2 commoned together; VCC refers to VCCA and VCCD commoned together. Note 2: In the circuits shown in Figures 9 and 10 , terminated in 135X, this is equivalent to g 2.5V for isolated pulses of the outer levels. Selection of this test mode is described in the TP3410 Users Manual AN-913. 26 Timing Characteristics Symbol FMCK Parameter Conditions Master Clock Frequency Master Clock Tolerance Including Temperature, Aging, Etc. MCLK/XTAL Input Clock Jitter External Clock Source tMH, tML Clock Pulse Width Hi & Low for MCLK VIH e VCC b 0.5V VIL e 0.5V tMR, tMF Rise and Fall Time of MCLK Used as a Logic Input Min Typ Max Units a 100 MHz ppm 50 ns pk-pk 15.36 b 100 20 ns 10 ns 4096 6144 kHz kHz DIGITAL INTERFACE (Figures 11, 12 and 13 ) FBCLK Frequency of BCLK Formats 1, 2 and 3 GCI and Format 4 256 512 tWBH Period of BCLK High Measured from VIH to VIH (Input) 25 tWBL Period of BCLK Low Measured from VIL to VIL (Input) 25 tRB Rise Time of BCLK Measured from VIL to VIH (Input) 15 ns tFB Fall Time of BCLK Measured from VIH to VIL (Input) 15 ns tSFB Setup Time, FS High to BCLK Low DSI or GCI Slave Only tHBF Hold Time, BCLK Low to FS, High or Low DSI or GCI Slave Only tDBF Delay Time, BCLK High to FSa and FSb Transitions DSI or GCI Master Only tDBD Delay Time, BCLK High to Data Valid All Modes Load e 150 pF Plus 2 LSTTL Loads tDBZ Delay Time, BCLK High to Br, Dr Disabled All Modes tDBT Delay Time, BCLK High to TSr Low if FS High, or FS High to TSr Low if BCLK High Load e 100 pF Plus 2 LSTTL Loads tZBT TRI-STATE Time, BCLK Low to TSr High tDFD Delay Time, FS High to Data Valid Load e 150 pF Plus 2 LSTTL Loads, Applies if FS Rises Later than BCLK Rising Edge in Non-Delayed Data Mode Only tSDB Setup Time, Data Valid to BCLK Low All Modes tHBD Hold Time, BCLK Low to Data Invalid All Modes 27 ns ns 50 ns 25 ns 50 ns 80 ns 55 ns 55 ns 55 ns 80 ns 0 ns 25 ns Timing Characteristics (Continued) Symbol Parameter Conditions Min Typ Max Units MICROWIRE CONTROL INTERFACE (see Figure 14 ) tCH CCLK High Duration 50 ns tCL CCLK Low Duration 50 ns tSIC Setup Time, CI Valid to CCLK High 25 ns tHCI Hold Time, CCLK High to CI Invalid 25 ns tSSC Setup Time from CS Low to CCLK High 50 ns tDCSO Delay Time from CS Low to CO Valid Byte 1, Bit C7 Only tDCO Delay Time from CCLK Low to CO Data Valid Load e 50 pF Plus 2 LSTTL Inputs tDCZ Delay Time from CS High to CO TRI-STATE tSCSC1 Setup Time, CS Low to CCLK Edge High 50 ns tHCSC1 Hold Time, CS High to CCLK Edge Low 50 ns tHCSC2 Hold Time, CS High to CCLK Edge High 12 ns tHCSC3 Hold Time, CCLK Low to CS Transition 12 ns tCSH Duration of CS High 200 ns tDCI Delay Time CCLK High to INT High-Impedance 50 ns 50 ns 50 ns 50 ns D PORT IN 16 kHz MODE (Figure 4) tSDXC Setup Time, Dx to DCLK 65 ns tHCDX Hold Time, DCLK to Dx 0 ns tDCDR Delay Time, DCLK to Dr Load e 50 pF Plus 2 LSTTL Inputs 28 80 ns Timing Diagrams TL/H/9151 – 28 TL/H/9151 – 21 FIGURE 11. Non-Delayed Data Timing Mode (Formats 1 and 3) TL/H/9151 – 22 FIGURE 12. Delayed Data Timing Mode (Formats 1, 2 and 3) (Shown with TS0 Selected) 29 Timing Diagrams (Continued) TL/H/9151 – 23 Note 1: As an output (GCI Master) FSa is high for 8 bit intervals (16 BCLK cycles). As an input (GCI Slave) FSa must be high for t 1 BCLK cycle. FIGURE 13. GCI and Format 4 Timing TL/H/9151 – 24 FIGURE 14a. TP3410 Enhanced MICROWIRE Control Port Timing 30 Timing Diagrams (Continued) TL/H/9151 – 29 FIGURE 14b. TP3410 Normal MICROWIRE CLOCK Format TL/H/9151 – 30 FIGURE 14c. TP3410 Alternate MICROWIRE CLOCK Format 31 TP3410 ISDN Basic Access Echo-Cancelling U Transceiver Physical Dimensions inches (millimeters) Ceramic Dual-In-Line Package (J) Order Number TP3410J NS Package Number J28A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation 1111 West Bardin Road Arlington, TX 76017 Tel: 1(800) 272-9959 Fax: 1(800) 737-7018 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Europe Fax: (a49) 0-180-530 85 86 Email: cnjwge @ tevm2.nsc.com Deutsch Tel: (a49) 0-180-530 85 85 English Tel: (a49) 0-180-532 78 32 Fran3ais Tel: (a49) 0-180-532 93 58 Italiano Tel: (a49) 0-180-534 16 80 National Semiconductor Hong Kong Ltd. 13th Floor, Straight Block, Ocean Centre, 5 Canton Rd. Tsimshatsui, Kowloon Hong Kong Tel: (852) 2737-1600 Fax: (852) 2736-9960 National Semiconductor Japan Ltd. Tel: 81-043-299-2309 Fax: 81-043-299-2408 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.