DS21448 3.3V E1/T1/J1 Quad Line Interface www.maxim-ic.com GENERAL DESCRIPTION The DS21448 is a quad-port E1 or T1 line interface unit (LIU) for short-haul and long-haul applications. It incorporates four independent transmitters and four independent receivers in a single 144-pin PBGA or 128-pin LQFP package. The transmit drivers generate the necessary G.703 E1 waveshapes in 75W or 120W applications and the DSX-1 or CSU line build-outs of 0dB, -7.5dB, -15dB, and -22.5dB for T1 applications. The DS21448 has a usable receiver sensitivity of 0 to -43dB for E1 applications and 0 to -36dB for T1 that allows it to operate on 0.63mm (22AWG) cables up to 2.5km (E1) and 6000ft (T1) in length. The user has the option to use internal receive termination, software selectable for 75W, 100W, and 120W applications, or external termination. The on-board crystal-less jitter attenuator can be placed in either the transmit or the receive data path, and requires only a 2.048MHz MCLK for both E1 and T1 applications (with the option of using a 1.544MHz MCLK in T1 applications). The DS21448 has diagnostic capabilities such as loopbacks and PRBS pattern generation and detection. 16-bit loop-up and loop-down codes can be generated and detected. A single input pin can power down all transmitters to allow the implementation of hitless protection switching (HPS) for 1+1 redundancy without the use of relays. The device can be controlled through an 8-bit parallel port (muxed or nonmuxed) or a serial port, and it can be used in hardware mode. A standard boundary scan interface supports board-level testing. APPLICATIONS Integrated Multiservice Access Platforms T1/E1 Cross-Connects, Multiplexers, and Channel Banks Central-Office Switches and PBX Interfaces T1/E1 LAN/WAN Routers Wireless Base Stations FEATURES § § § Four Complete E1, T1, or J1 LIUs Supports Long- and Short-Haul Trunks Internal Software-Selectable Receive-Side Termination for 75W/100W/120W 3.3V Power Supply 32-Bit or 128-Bit Crystal-Less Jitter Attenuator Requires Only a 2.048MHz Master Clock for E1 and T1, with the Option to Use 1.544MHz for T1 Generates the Appropriate Line Build-Outs With and Without Return Loss for E1, and DSX-1 and CSU Line Build-Outs for T1 AMI, HDB3, and B8ZS Encoding/Decoding 16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz Clock Output Synthesized to Recovered Clock Programmable Monitor Mode for Receiver Loopbacks and PRBS Pattern Generation/ Detection with Output for Received Errors Generates/Detects In-Band Loop Codes, 1 to 16 Bits, Including CSU Loop Codes 8-Bit Parallel or Serial Interface with Optional Hardware Mode Muxed and Nonmuxed Parallel Bus Supports Intel or Motorola Detects/Generates Blue (AIS) Alarms NRZ/Bipolar Interface for Tx/Rx Data I/O Transmit Open-Circuit Detection Receive Carrier Loss (RCL) Indication (G.775) High-Z State for TTIP and TRING 50mARMS Transmit Current Limiter JTAG Boundary Scan Test Port per IEEE 1149.1 Meets Latest E1 and T1 Specifications Including ANSI.403-1999, ANSI T1.408, AT&T TR 62411, ITU G.703, G.704, G.706, G.736, G.775, G.823, I.431, O.151, O.161, ETSI ETS 300 166, JTG.703, JTI.431, TBR12, TBR13, and CTR4 § § § § § § § § § § § § § § § § § § ORDERING INFORMATION PART TEMP RANGE DS21448 DS21448N DS21448L DS21448LN 0°C to +70°C -40°C to +85°C 0°C to +70°C -40°C to +85°C VOLTAGE (V) 3.3 3.3 3.3 3.3 PINPACKAGE 144 BGA 144 BGA 128 LQFP 128 LQFP Pin Configurations appear in Section 11. Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata. 1 of 60 REV: 012104 DS21448 3.3V T1/E1/J1 Quad Line Interface TABLE OF CONTENTS 1. 2. 3. 3.1 4. 4.1 4.2 4.3 5. 6. BLOCK DIAGRAMS...................................................................................................................... 5 PIN DESCRIPTION ....................................................................................................................... 7 DETAILED DESCRIPTION...........................................................................................................13 DS21448 AND DS21Q348 DIFFERENCES ....................................................................................13 PORT OPERATION......................................................................................................................13 HARDWARE MODE .......................................................................................................................13 SERIAL PORT OPERATION ............................................................................................................15 PARALLEL PORT OPERATION .......................................................................................................17 4.3.1 Device Power-Up and Reset.................................................................................................................17 4.3.2 Register Map.........................................................................................................................................18 4.3.3 Control Registers ..................................................................................................................................19 STATUS REGISTERS..................................................................................................................23 DIAGNOSTICS ............................................................................................................................27 6.1 IN-BAND LOOP-CODE GENERATION AND DETECTION .....................................................................27 6.2 LOOPBACKS ................................................................................................................................31 6.2.1 Remote Loopback (RLB) ......................................................................................................................31 6.2.2 Local Loopback (LLB) ...........................................................................................................................31 6.2.3 Analog Loopback (LLB) ........................................................................................................................31 6.2.4 Dual Loopback (DLB)............................................................................................................................31 6.3 6.4 6.5 6.6 PRBS GENERATION AND DETECTION ...........................................................................................31 ERROR COUNTER ........................................................................................................................31 ERROR COUNTER UPDATE ...........................................................................................................32 ERROR INSERTION.......................................................................................................................32 7. ANALOG INTERFACE.................................................................................................................33 7.1 RECEIVER ...................................................................................................................................33 7.2 TRANSMITTER .............................................................................................................................33 7.3 JITTER ATTENUATOR ...................................................................................................................34 7.4 G.703 SYNCHRONIZATION SIGNAL ...............................................................................................34 8. JTAG BOUNDARY SCAN ARCHITECTURE AND TEST ACCESS PORT..................................43 8.1 JTAG TAP CONTROLLER STATE MACHINE ...................................................................................43 8.2 INSTRUCTION REGISTER ..............................................................................................................45 8.3 TEST REGISTERS ........................................................................................................................46 9. OPERATING PARAMETERS.......................................................................................................48 10. AC TIMING PARAMETERS AND DIAGRAMS ............................................................................49 11. PIN CONFIGURATIONS ..............................................................................................................56 11.1 144-PIN BGA ..........................................................................................................................56 11.2 128-PIN LQFP.........................................................................................................................57 12. PACKAGE INFORMATION..........................................................................................................58 13. THERMAL INFORMATION ..........................................................................................................60 14. REVISION HISTORY....................................................................................................................60 2 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface LIST OF FIGURES Figure 1-1. Block Diagram ....................................................................................................................... 5 Figure 1-2. Receive Logic Detail.............................................................................................................. 6 Figure 1-3. Transmit Logic Detail............................................................................................................. 6 Figure 4-1. Serial Port Operation for Read Access (R = 1) Mode 1 ........................................................15 Figure 4-2. Serial Port Operation for Read Access (R = 1) Mode 2 ........................................................16 Figure 4-3. Serial Port Operation for Read Access (R = 1) Mode 3 ........................................................16 Figure 4-4. Serial Port Operation for Read Access (R = 1) Mode 4 ........................................................16 Figure 4-5. Serial Port Operation for Write Access (R = 0) Modes 1 and 2 .............................................17 Figure 4-6. Serial Port Operation for Write Access (R = 0) Modes 3 and 4 .............................................17 Figure 7-1. Basic Interface......................................................................................................................36 Figure 7-2. Protected Interface Using Internal Receive Termination .......................................................37 Figure 7-3. Protected Interface Using External Receive Termination......................................................38 Figure 7-4. Dual Connector-Protected Interface Using Receive Termination ..........................................39 Figure 8-5. E1 Transmit Pulse Template ................................................................................................40 Figure 8-6. T1 Transmit Pulse Template.................................................................................................41 Figure 7-7. Jitter Tolerance.....................................................................................................................42 Figure 7-8. Jitter Attenuation ..................................................................................................................42 Figure 8-1. JTAG Block Diagram ............................................................................................................43 Figure 8-2. TAP Controller State Diagram ..............................................................................................44 Figure 10-1. Intel Bus Read Timing (PBTS = 0, BIS0 = 0) ......................................................................49 Figure 10-2. Intel Bus Write Timing (PBTS = 0, BIS0 = 0) ......................................................................50 Figure 10-3. Motorola Bus Timing (PBTS = 1, BIS0 = 0) ........................................................................50 Figure 10-4. Intel Bus Read Timing (PBTS = 0, BIS0 = 1) ......................................................................51 Figure 10-5. Intel Bus Write Timing (PBTS = 0, BIS0 = 1) ......................................................................52 Figure 10-6. Motorola Bus Read Timing (PBTS = 1, BIS0 = 1) ...............................................................52 Figure 10-7. Motorola Bus Write Timing (PBTS = 1, BIS0 = 1) ...............................................................52 Figure 10-8. Serial Bus Timing (BIS1 = 1, BIS0 = 0)...............................................................................53 Figure 10-9. Receive-Side Timing ..........................................................................................................54 Figure 10-10. Transmit-Side Timing .......................................................................................................55 3 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface LIST OF TABLES Table 2-A. Bus Interface Selection .......................................................................................................... 7 Table 2-B. Pin Assignments .................................................................................................................... 7 Table 2-C. Parallel Interface Mode Pin Description ................................................................................. 9 Table 2-D. Serial Interface Mode Pin Description ...................................................................................10 Table 2-E. Hardware Interface Mode Pin Description .............................................................................11 Table 3-A. DS21448 vs. DS21Q348 Pin Differences ..............................................................................13 Table 4-A. Loopback Control in Hardware Mode ....................................................................................14 Table 4-B. Transmit Data Control in Hardware Mode .............................................................................14 Table 4-C. Receive Sensitivity Settings in Hardware Mode ....................................................................14 Table 4-D. Monitor Gain Settings in Hardware Mode..............................................................................14 Table 4-E. Internal Rx Termination Select in Hardware Mode ................................................................14 Table 4-F. MCLK Selection in Hardware Mode.......................................................................................14 Table 4-G. Parallel Port Mode Selection.................................................................................................18 Table 4-H. Register Map ........................................................................................................................18 Table 4-I. Receive Sensitivity Settings....................................................................................................22 Table 4-J. Backplane Clock Select .........................................................................................................22 Table 4-K. Monitor Gain Settings............................................................................................................22 Table 4-L. Internal Rx Termination Select...............................................................................................22 Table 5-A. Received Alarm Criteria ........................................................................................................25 Table 5-B. Receive Level Indication .......................................................................................................27 Table 6-A. Transmit Code Length...........................................................................................................29 Table 6-B. Receive Code Length............................................................................................................29 Table 6-C. Definition of Received Errors.................................................................................................32 Table 6-D. Function of ECRS Bits and RNEG Pin ..................................................................................32 Table 7-A. Line Build-Out Select for E1 in Register CCR4 (ETS = 0)......................................................34 Table 7-B. Line Build-Out Select for T1 in Register CCR4 (ETS = 1)......................................................34 Table 7-C. Line Build-Out Select for E1 in Register CCR4 (ETS = 0) Using Alternate Transformer Configuration ...................................................................................................................................35 Table 7-D. Transformer Specifications (3.3V Operation) ........................................................................35 Table 8-A. Instruction Codes for IEEE 1149.1 Architecture.....................................................................45 Table 8-B. ID Code Structure .................................................................................................................46 Table 8-C. Device ID Codes ...................................................................................................................46 Table 8-D. Boundary Scan Control Bits ..................................................................................................47 Table 10-A. AC Characteristics—Multiplexed Parallel Port (BIS0 = 0) ....................................................49 Table 10-B. AC Characteristics—Nonmultiplexed Parallel Port (BIS0 = 1) .............................................51 Table 10-C. AC Characteristics—Serial Port (BIS1 = 1, BIS0 = 0)..........................................................53 Table 10-D. AC Characteristics—Receive Side ......................................................................................54 Table 10-E. AC Characteristics—Transmit Side .....................................................................................55 Table 13-A. Thermal Characteristics—BGA ...........................................................................................60 Table 13-B. Theta-JA (qJA) vs. Airflow—BGA..........................................................................................60 Table 13-C. Thermal Characteristics—LQFP..........................................................................................60 Table 13-D. Theta-JA (qJA) vs. Airflow—LQFP........................................................................................60 4 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface 1. BLOCK DIAGRAMS Figure 1-1. Block Diagram CHANNEL 4 CHANNEL 3 CHANNEL 2 CHANNEL 1 JACLK POWER CONNECTIONS 2.048MHz TO 1.544MHz PLL 16.384MHz OR 8.192MHz OR 4.096MHz OR 2.048MHz SYNTHESIZER LOCAL LOOPBACK MUX REMOTE LOOPBACK PBEO MUX TXDIS/TEST JTAG PORT 5 of 60 JTDO JTDI JRST INT 8 D0 TO D7/AD0 TO AD7 A0 TO A4 ALE (AS) RD(DS) WR (R/W) PBTS SDO SDI HRST CONTROL AND TEST PORT (ROUTED TO ALL BLOCKS) CONTROL AND (ROUTED TO ALL BLOCKS) PARALLEL INTERFACE 5 SCLK TPOS TCLK TNEG CS SERIAL INTERFACE RCL/LOTC See Figure 1-3 MUX (THE SERIAL, PARALLEL, AND HARDWARE INTERFACES SHARE DEVICE PINS) BIS0 BPCLK RPOS RCLK RNEG See Figure 1-2 JTMS TTIP WAVESHAPING TRING CSU FILERS LINE DRIVERS UNFRAMED ALL-ONES INSERTION JITTER ATTENUATION (CAN BE PLACED IN EITHER TRANSMIT OR RECEIVE PATH) CLOCK/DATA RECOVERY PEAK DETECT n REMOTE LOOPBACK (DUAL MODE) ANALOG LOOPBACK RTIP FILTER RRING OPTIONAL TERMINANATION VCO/PLL JTCLK 2 JITTER ATTENUATOR MUX VSM VDD VSS 2 MCLK TYPICAL OF ALL FOUR CHANNELS Dallas Semiconductor DS21448 DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 1-2. Receive Logic Detail RCLK CLOCK INVERT FROM REMOTE LOOPBACK ROUTED TO ALL BLOCKS CCR2.0 RPOS MUX NRZ DATA B8ZS/HDB3 DECODER ALL-ONES DETECTOR LOOP CODE DETECTOR SR.4 RIR1.3 SR.6 CCR1.6 PRBS DETECTOR PBEO CCR2.3 4 OR 8 ZERO DETECT CCR6.2/ RIR1.5 CCR6.0/ CCR6.1 16 ZERO DETECT RIR1.7 RNEG BPV/CV/EXZ SR.7 CCR1.4 RIR1.6 CCR6.0 MUX SR.0 16-BIT ERROR COUNTER (ECR) Figure 1-3. Transmit Logic Detail CCR3.3 CCR1.6 CCR3.4 CCR2.2 CCR3.1 PRBS GENERATOR CCR3.0 OR GATE LOOP CODE GENERATOR MUX B8ZS/ HDB3 CODER 1 LOGIC ERROR INSERT BPV INSERT TPOS OR GATE TNEG MUX TO REMOTE LOOPBACK 0 0 0 MUX 1 RCLK MUX JACLK (FROM MCLK) 1 CCR1.1 ROUTED TO ALL BLOCKS OR GATE CCR1.2 AND GATE CCR1.0 6 of 60 LOSS-OF-TRANSMIT CLOCK DETECT TO LOTC OUTPUT PIN SR.5 CLOCK INVERT CCR2.1 TCLK DS21448 3.3V T1/E1/J1 Quad Line Interface 2. PIN DESCRIPTION The DS21448 can be controlled in parallel port mode, serial port mode, or hardware mode. The bus interface select bits 0 and 1 (BIS0, BIS1) determine the device mode and pin assignments (Table 2-A). Table 2-A. Bus Interface Selection BIS1 0 0 1 1 BIS0 0 1 0 1 BUS INTERFACE TYPE Parallel Port Mode (multiplexed) Parallel Port Mode (nonmultiplexed) Serial Port Mode Hardware Mode Table 2-B. Pin Assignments PIN BGA J3 D3 D10 K10 J2 H1 K2 J1 K3 K1 L1 H11 H12 G12 J10 H10 G11 J9 E3 D4 F3 D5 — L5 E4 D8 J8 M4 F4 D9 H9 K9 K5 G3 E10 K8 L6 D7 F9 J7 K7 A1 A4 A7 A10 B2 B5 LQFP 18 57 84 114 91 92 95 35 36 62 63 64 65 66 75 76 77 78 79 80 81 82 3 115–117 19–21 49–51 85–87 118–120 22–24 52–54 88–90 97 110 111 121 123 126 128 1 2 98 124 28 60 93 125 29 I/O PARALLEL PORT MODE SERIAL PORT MODE HARDWARE MODE I I I I I I I I I I/O I I I I I/O I/O I/O I/O I/O I/O I/O I/O I — — — — — — — — I/O O O O O O O O O I I I I I I I CS1 CS2 CS3 CS4 RD (DS) WR (R/W) ALE (AS) N/A N/A A4 A3 A2 A1 A0 D7/AD7 D6/AD6 D5/AD5 D4/AD4 D3/AD3 D2/AD2 D1/AD1 D0/AD0 VSM VDD1 VDD2 VDD3 VDD4 VSS1 VSS2 VSS3 VSS4 INT PBEO1 PBEO2 PBEO3 PBEO4 RCL1/LOTC1 RCL2/LOTC2 RCL3/LOTC3 RCL4/LOTC4 TXDIS/TEST RTIP1 RTIP2 RTIP3 RTIP4 RRING1 RRING2 CS1 CS2 CS3 CS4 N/A N/A N/A SCLK SDI SDO ICES OCES N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A VSM VDD1 VDD2 VDD3 VDD4 VSS1 VSS2 VSS3 VSS4 INT PBEO1 PBEO2 PBEO3 PBEO4 RCL1/LOTC1 RCL2/LOTC2 RCL3/LOTC3 RCL4/LOTC4 TXDIS/TEST RTIP1 RTIP2 RTIP3 RTIP4 RRING1 RRING2 EGL1 EGL2 EGL3 EGL4 ETS NRZE SCLKE L2 L1 L0 DJA JAMUX JAS HBE CES TPD TX0 TX1 LOOP0 LOOP1 MM0 MM1 VSM VDD1 VDD2 VDD3 VDD4 VSS1 VSS2 VSS3 VSS4 RT1 PBEO1 PBEO2 PBEO3 PBEO4 RCL1 RCL2 RCL3 RCL4 TXDIS/TEST RTIP1 RTIP2 RTIP3 RTIP4 RRING1 RRING2 7 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface PIN BGA B8 B11 L9 J6 H4 D6 F10 L8 L7 M8 A2 A5 A8 A11 J4 D1 E9 L10 J5 D2 G9 M9 B3 B6 B9 B12 K4 E1 D11 K11 G2 E2 F11 M10 H3 F1 E11 L11 G1 F2 E12 M11 H2 M1 D12 K12 M2 L2 F12 L12 M12 L3 M3 M5 M6 M7 LQFP 61 94 106 109 122 47 56 112 107 68 6 38 71 102 7 39 72 103 8 40 73 104 9 41 74 105 10 12 14 16 11 13 15 25 127 31 58 96 26 30 33 55 27 32 34 59 17 43 83 113 108 42 48 44 45 46 I/O PARALLEL PORT MODE SERIAL PORT MODE HARDWARE MODE I I I I O O O O I I O O O O — — — — — — — — O O O O O O O O O O O O O O O O I I I I I I I I I I I I I I I I I O RRING3 RRING4 HRST MCLK BPCLK1 BPCLK2 BPCLK3 BPCLK4 BIS0 BIS1 TTIP1 TTIP2 TTIP3 TTIP4 TVSS1 TVSS2 TVSS3 TVSS4 TVDD1 TVDD2 TVDD3 TVDD4 TRING1 TRING2 TRING3 TRING4 RPOS1 RPOS2 RPOS3 RPOS4 RNEG1 RNEG2 RNEG3 RNEG4 RCLK1 RCLK2 RCLK3 RCLK4 TPOS1 TPOS2 TPOS3 TPOS4 TNEG1 TNEG2 TNEG3 TNEG4 TCLK1 TCLK2 TCLK3 TCLK4 PBTS JTRST JTMS JTCLK JTDI JTDO RRING3 RRING4 HRST MCLK BPCLK1 BPCLK2 BPCLK3 BPCLK4 BIS0 BIS1 TTIP1 TTIP2 TTIP3 TTIP4 TVSS1 TVSS2 TVSS3 TVSS4 TVDD1 TVDD2 TVDD3 TVDD4 TRING1 TRING2 TRING3 TRING4 RPOS1 RPOS2 RPOS3 RPOS4 RNEG1 RNEG2 RNEG3 RNEG4 RCLK1 RCLK2 RCLK3 RCLK4 TPOS1 TPOS2 TPOS3 TPOS4 TNEG1 TNEG2 TNEG3 TNEG4 TCLK1 TCLK2 TCLK3 TCLK4 N/A JTRST JTMS JTCLK JTDI JTDO RRING3 RRING4 HRST MCLK BPCLK1 BPCLK2 BPCLK3 BPCLK4 BIS0 BIS1 TTIP1 TTIP2 TTIP3 TTIP4 TVSS1 TVSS2 TVSS3 TVSS4 TVDD1 TVDD2 TVDD3 TVDD4 TRING1 TRING2 TRING3 TRING4 RPOS1 RPOS2 RPOS3 RPOS4 RNEG1 RNEG2 RNEG3 RNEG4 RCLK1 RCLK2 RCLK3 RCLK4 TPOS1 TPOS2 TPOS3 TPOS4 TNEG1 TNEG2 TNEG3 TNEG4 TCLK1 TCLK2 TCLK3 TCLK4 RT0 JTRST JTMS JTCLK JTDI JTDO Note 1: The VSM signal is not available with the BGA package option. Note 2: The LQFP no-connect pin numbers are 4, 5, 37, 67, 69, 70, and 99–101. Note 3: The BGA no-connect pin numbers are A3, A6, A9, A12, B1, B4, B7, B10, C1–C12, E5–E8, F5–F8, G4–G8, G10, H5–H8, J11, J12, K6, and L4. 8 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface Table 2-C. Parallel Interface Mode Pin Description PIN I/O RD (DS) I WR (R/W) I ALE (AS) I A4–A0 I D7/AD7–D0/AD0 I/O INT O TXDIS/TEST I HRST I MCLK I BIS0/BIS1 I PBTS I CS1–CS4 I PBEO1–PBEO4 O RCL1/LOTC1– RCL4/LOTC4 O RTIP1–RTIP4 RRING1–RRING4 I I BPCLK1–BPCLK4 O TTIP1–TTIP4 TRING1–TRING4 O O RPOS1–RPOS4 RNEG1–RNEG4 FUNCTION Read Input (Data Strobe). RD and DS are active-low signals. DS is active low when in nonmultiplexed, Motorola mode. See the bus timing diagrams in Section 10. Write Input (Read/Write). WR is an active-low signal. See the bus timing diagrams in Section 10. Address Latch Enable (Address Strobe). When using multiplexed bus mode (BIS0 = 0), this pin serves to demultiplex the bus on a positive-going edge. In nonmultiplexed bus mode (BIS0 = 1), ALE should be wired low. Address Bus. In nonmultiplexed bus operation (BIS0 = 1), these pins serve as the address bus. In multiplexed bus operation (BIS0 = 0), these pins are not used and should be wired low. Data Bus/Address/Data Bus. In nonmultiplexed bus operation (BIS0 = 1), these pins serve as the data bus. In multiplexed bus operation (BIS0 = 0), these pins serve as an 8-bit multiplexed address/data bus. Interrupt (INT). The interrupt flags the host controller during conditions and change of conditions defined in the status register. It is an active-low, open-drain output. Tri-State Control, Multifunctional. Set this pin high, with all CS1–CS4 inputs inactive, to tri-state TTIP1–TTIP4 and TRING1–TRING4. Set this pin high with any of the CS1–CS4 inputs active to tri-state all outputs and I/O pins (including the parallel control port). Set low for normal operation. Hardware Reset. Bringing HRST low resets the DS21448, setting all control bits to the all-zeros default state. Master Clock. A 2.048MHz (±50ppm) clock source with TTL levels is applied at this pin. This clock is used internally for both clock/data recovery and for jitter attenuation. Use of a T1 1.544MHz clock source is optional (Note 1). Bus Interface Select Bit 0 and 1. Used to select bus interface option. See Table 2-A for details. Parallel Bus Type Select. When using the parallel port, set PBTS high to select Motorola bus timing; set low to select Intel bus timing. This pin controls the function of the RD (DS), ALE (AS), and WR (R/W) pins. Chip Select 1. Must be low to read or write to channel 1 of the device. CS1 is an active-low signal. Chip Select 2. Must be low to read or write to channel 2 of the device. CS2 is an active-low signal. Chip Select 3. Must be low to read or write to channel 3 of the device. CS3 is an active-low signal. Chip Select 4. Must be low to read or write to channel 4 of the device. CS4 is an active-low signal. 15 PRBS Bit-Error Output. The receiver constantly searches for a 2 - 1 (E1) or a QRSS (T1) PRBS, depending on the ETS bit setting (CCR1.7). It remains high if it is out of synchronization with the PRBS pattern. It goes low when synchronized to the PRBS pattern. Any errors in the received pattern after synchronization cause a positive-going pulse (with same period as E1 or T1 clock) synchronous with RCLK. PRBS bit errors can also be reported to the ECR1 and ECR2 registers by setting CCR6.2 to logic 1. Receive Carrier Loss/Loss-of-Transmit Clock. An output that toggles high during a receive carrier loss (CCR2.7 = 0) or toggles high if the TCLK pin has not been toggled for 5ms ± 2ms (CCR2.7 = 1). CCR2.7 defaults to logic 0 when in hardware mode. Receive Tip and Ring. Analog inputs for clock recovery circuitry. These pins connect through a 1:1 transformer to the line. See Section 7 for details. Backplane Clock. A 16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz clock output that is referenced to RCLK selectable through CCR5.7 and CCR5.6. Transmit Tip and Ring. Analog line-driver outputs. These pins connect through a step-up transformer to the line. See Section 7 for details. O Receive Positive Data. These bits are updated on the rising edge (CCR2.0 = 0) or the falling edge (CCR2.0 = 1) of RCLK with bipolar data out of the line interface. Set NRZE (CCR1.6) to 1 for NRZ applications. In NRZ mode, data is output on RPOS, and a received error (BPV, CV, or EXZ) causes a positive-going pulse synchronous with RCLK at RNEG. O Receive Negative Data. Updated on the rising edge (CCR2.0 = 0) or the falling edge (CCR2.0 = 1) of RCLK with the bipolar data out of the line interface. Set NRZE (CCR1.6) to 1 for NRZ applications. In NRZ mode, data is output on RPOS, and a received error (BPV, CV, or EXZ) causes a positive-going pulse synchronous with RCLK at RNEG. 9 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface PIN I/O RCLK1–RCLK4 O TPOS1–TPOS4 I TNEG1–TNEG4 I TCLK1–TCLK4 I JTRST JTMS JTCLK JTDI JTDO VSM TVDD1–TVDD4 VDD1–VDD4 TVSS1–TVSS4 VSS1–VSS4 I I I I O I — — — — FUNCTION Receive Clock. Buffered recovered clock from the line. Synchronous to MCLK in absence of signal at RTIP and RRING. Transmit Positive Data. Sampled on the falling edge (CCR2.1 = 0) or the rising edge (CCR2.1 = 1) of TCLK for data to be transmitted out onto the line. Transmit Negative Data. Sampled on the falling edge (CCR2.1 = 0) or the rising edge (CCR2.1 = 1) of TCLK for data to be transmitted out onto the line. Transmit Clock. A 2.048MHz or 1.544MHz primary clock. It is used to clock data through the transmit-side formatter. It can be sourced internally by MCLK or RCLK. See Common Control Register 1 and Figure 1-3. JTAG Reset JTAG Mode Select JTAG Clock JTAG Data In JTAG Data Out Voltage Supply Mode (LQFP only). Should be wired low for correct operation. 3.3V, ±5% Transmitter Positive Supply 3.3V, ±5% Positive Supply Transmitter Signal Ground Signal Ground Table 2-D. Serial Interface Mode Pin Description PIN I/O INT I/O TXDIS/TEST I HRST I MCLK I BIS0/BIS1 I CS1 I CS2 I CS3 I CS4 I ICES I OCES I SCLK SDI SDO I I O PBEO1–PBEO4 O RCL1/LOTC1– RCL4/LOTC4 O RTIP1–RTIP4 RRING1–RRING4 I FUNCTION Interrupt (INT). Flags host controller during conditions and change of conditions defined in the status register. Active-low, open-drain output. Tri-State Control, Multifunctional. Set this pin high with all CS1–CS4 inputs inactive to tri-state TTIP1–TTIP4 and TRING1–TRING4. Set this pin high with any of the CS1–CS4 inputs active to tri-state all outputs and I/O pins (including the parallel control port). Set low for normal operation. Hardware Reset. Bringing HRST low resets the DS21448, setting all control bits to the all-zeros default state. Master Clock. A 2.048MHz (±50ppm) clock source with TTL levels is applied at this pin. This clock is used internally for both clock/data recovery and for jitter attenuation. A T1 1.544MHz clock source is optional (Note 1). Bus Interface Select Bit 0 and 1. Used to select bus interface option. See Table 2-A for details. Chip Select 1. Must be low to read or write to channel 1 of the device. CS1 is an active-low signal. Chip Select 2. Must be low to read or write to channel 2 of the device. CS2 is an active-low signal. Chip Select 3. Must be low to read or write to channel 3 of the device. CS3 is an active-low signal. Chip Select 4. Must be low to read or write to channel 4 of the device. CS4 is an active-low signal. Input Clock-Edge Select. Selects whether the serial interface data input (SDI) is sampled on the rising (ICES = 0) or falling edge (ICES = 1) of SCLK. Output Clock-Edge Select. Selects whether the serial interface data output (SDO) changes on the rising (OCES = 1) or falling edge (OCES = 0) of SCLK. Serial Clock. Serial interface clock. Serial Data Input. Serial interface data input. Serial Data Output. Serial interface data output. 15 PRBS Bit-Error Output. The receiver constantly searches for a 2 - 1 (E1) or a QRSS (T1) PRBS, depending on the ETS bit setting (CCR1.7). It remains high if it is out of synchronization with the PRBS pattern. It goes low when synchronized to the PRBS pattern. Any errors in the received pattern after synchronization cause a positive-going pulse (with same period as E1 or T1 clock) synchronous with RCLK. PRBS bit errors can also be reported to the ECR1 and ECR2 registers by setting CCR6.2 to logic 1. Receive Carrier Loss/Loss-of-Transmit Clock. An output that toggles high during a receive carrier loss (CCR2.7 = 0) or toggles high if the TCLK pin has not been toggled for 5ms ± 2ms (CCR2.7 = 1). CCR2.7 defaults to logic 0 when in hardware mode. Receive Tip and Ring. Analog inputs for clock recovery circuitry. These pins connect through a 1:1 transformer to the line. See Section 7 for details. 10 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface PIN I/O BPCLK1–BPCLK4 O TTIP1–TTIP4 TRING–TRING4 O O RPOS1–RPOS4 O RNEG1–RNEG4 O RCLK1–RCLK4 O TPOS1–TPOS4 I TNEG1–TNEG4 I TCLK1–TCLK4 I JTRST JTMS JTCLK JTDI JTDO VSM TVDD1–TVDD4 VDD1–VDD4 TVSS1–TVSS4 VSS1–VSS4 I I I I O I — — — — FUNCTION Backplane Clock. A 16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz clock output that is referenced to RCLK selectable through CCR5.7 and CCR5.6. Transmit Tip and Ring. Analog line-driver outputs. These pins connect through a step-up transformer to the line. See Section 7 for details. Receive Positive Data. Updated on the rising edge (CCR2.0 = 0) or the falling edge (CCR2.0 = 1) of RCLK with bipolar data out of the line interface. Set NRZE (CCR1.6) to 1 for NRZ applications. In NRZ mode, data is output on RPOS, and a received error (BPV, CV, or EXZ) causes a positive-going pulse synchronous with RCLK at RNEG. Receive Negative Data. Updated on the rising edge (CCR2.0 = 0) or the falling edge (CCR2.0 = 1) of RCLK with the bipolar data out of the line interface. Set NRZE (CCR1.6) to 1 for NRZ applications. In NRZ mode, data is output on RPOS, and a received error (BPV, CV, or EXZ) causes a positive-going pulse synchronous with RCLK at RNEG. Receive Clock. Buffered recovered clock from the line. Synchronous to MCLK in absence of signal at RTIP and RRING. Transmit Positive Data. Sampled on the falling edge (CCR2.1 = 0) or the rising edge (CCR2.1 = 1) of TCLK for data to be transmitted out onto the line. Transmit Negative Data. Sampled on the falling edge (CCR2.1 = 0) or the rising edge (CCR2.1 = 1) of TCLK for data to be transmitted out onto the line. Transmit Clock. A 2.048MHz or 1.544MHz primary clock used to clock data through the transmit side formatter. They can be sourced internally by MCLK or RCLK. See Common Control Register 1 and Figure 1-3. JTAG Reset JTAG Mode Select JTAG Clock JTAG Data In JTAG Data Out Voltage Supply Mode (LQFP only). VSM should be wired low for correct operation. 3.3V, ±5% Transmitter Positive Supply 3.3V, ±5% Positive Supply Transmitter Signal Ground for Transmitter Outputs Signal Ground Table 2-E. Hardware Interface Mode Pin Description PIN I/O ETS I NRZE I SCLKE I DJA I JAMUX I JAS I HBE I L0/L1/L2 I FUNCTION E1/T1 Select 0 = E1 1 = T1 NRZ Enable 0 = bipolar data at RPOS/RNEG and TPOS/TNEG 1 = NRZ data at RPOS and TPOS or TNEG; RNEG outputs a positive-going pulse when the device receives a BPV, CV, or EXZ. Receive and Transmit Synchronization Clock Enable. SCLKE combines RSCLKE (CCR5.3) and TSCLKE (CCR5.2). 0 = disable 2.048MHz synchronization transmit and receive mode 1 = enable 2.048MHz synchronization transmit and receive mode Disable Jitter Attenuator 0 = jitter attenuator enabled 1 = jitter attenuator disabled Jitter Attenuator Clock Mux. Controls the source for JACLK. 0 = JACLK sourced from MCLK (2.048MHz or 1.544MHz at MCLK). 1 = JACLK sourced from internal PLL (2.048 MHz at MCLK). Jitter Attenuator Path Select 0 = place the jitter attenuator on the receive side 1 = place the jitter attenuator on the transmit side Receive and Transmit HDB3/B8ZS Enable. HBE combines RHBE (CCR2.3) and THBE (CCR2.2). 0 = enable HDB3 (E1)/B8ZS (T1) 1 = disable HDB3 (E1)/B8ZS (T1) Line Build-Out Select Bits 0,1, and 2. These pins set the transmitter build-out; see (Table 7-A (E1) and Table 7-B (T1). 11 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface PIN I/O CES I TPD I TX0/TX1 I LOOP0/LOOP1 I MM0/MM1 I RT1/RT0 I TEST I HRST I MCLK I BIS0/BIS1 I EGL1–EGL4 I PBEO1–PBEO4 O RCL1–RCL4 RTIP1–RTIP4 RRING1–RRING4 BPCLK1–BPCLK4 TTIP1–TTIP4 TRING1–TRING4 O I I O RPOS1–RPOS4 O RNEG1–RNEG4 O RCLK1–RCLK4 O TPOS1–TPOS4 I TNEG1–TNEG4 I TCLK1–TCLK4 I JTRST JTMS JTCLK JTDI JTDO VSM TVDD1–TVDD4 VDD1–VDD4 I I I I O I – — O FUNCTION Receive and Transmit Clock Select. Selects which RCLK edge to update RPOS and RNEG and which TCLK edge to sample TPOS and TNEG. CES combines TCES and RCES. 0 = update RPOS/RNEG on rising edge of RCLK; sample TPOS/TNEG on falling edge of TCLK 1 = update RPOS/RNEG on falling edge of RCLK; sample TPOS/TNEG on rising edge of TCLK Transmit Power-Down 0 = normal transmitter operation 1 = powers down the transmitter and tri-states TTIP and TRING pins Transmit Data Source Select Bits 0 and 1. These inputs determine the source of the transmit data (Table 4-B). Loopback Select Bits 0 and 1. These inputs determine the active loopback mode (Table 4-A). Monitor Mode Select Bits 0 and 1. These inputs determine if the receive equalizer is in a monitor mode (Table 4-D). Receive LIU Termination Select Bits 0 and 1. These inputs determine the receive termination (Table 4-E). Tri-State Control. Set high to tri-state all outputs and I/O pins (including the parallel control port). Set low for normal operation. Useful in board-level testing. Hardware Reset. Bringing HRST low resets the DS21448, setting all control bits to the all-zero default state. Master Clock. A 2.048MHz (±50ppm) clock source with TTL levels is applied at this pin. This clock is used internally for both clock/data recovery and for jitter attenuation. A T1 1.544MHz clock source is optional (Note 1). See Table 4-F for details. Bus Interface Select Bit 0 and 1. Used to select bus interface option (Table 2-A). Receive Equalizer Gain-Limit Select. These bits control the sensitivity of the receive equalizers (Table 4-C). 15 PRBS Bit-Error Output. The receiver constantly searches for a 2 - 1 PRBS (ETS = 0) or a QRSS PRBS (ETS = 1). The pattern is chosen automatically by the value of the ETS pin. It remains high if it is out of synchronization with the PRBS pattern. It goes low when synchronized to the PRBS pattern. Any errors in the received pattern after synchronization cause a positivegoing pulse (with same period as E1 or T1 clock) synchronous with RCLK. Receive Carrier Loss. An output that toggles high during a receive carrier loss. Receive Tip and Ring. Analog inputs for clock recovery circuitry. These pins connect through a 1:1 transformer to the line. See Section 7 for details. Backplane Clock. A 16.384MHz clock output that is referenced to RCLK. Transmit Tip and Ring. Analog line-driver outputs. These pins connect through a step-up transformer to the line. See Section 7 for details. Receive Positive Data. Updated on the rising edge (CES = 0) or the falling edge (CES = 1) of RCLK with bipolar data out of the line interface. In NRZ mode (NRZE = 1), data is output on RPOS, and a received error (BPV, CV, or EXZ) causes a positive-going pulse synchronous with RCLK at RNEG. Receive Negative Data. Updated on the rising edge (CES = 0) or the falling edge (CES = 1) of RCLK with bipolar data out of the line interface. In NRZ mode (NRZE = 1), data is output on RPOS, and a received error (BPV, CV, or EXZ) causes a positive-going pulse synchronous with RCLK at RNEG. Receive Clock. Buffered recovered clock from the line. Synchronous to MCLK in absence of signal at RTIP and RRING. Transmit Positive Data. Sampled on the falling edge (CES = 0) or the rising edge (CES = 1) of TCLK for data to be transmitted out onto the line. Transmit Negative Data. Sampled on the falling edge (CES = 0) or the rising edge (CES = 1) of TCLK for data to be transmitted out onto the line. Transmit Clock. A 2.048MHz or 1.544MHz primary clock used to clock data through the transmit side formatter. It can be sourced internally by MCLK or RCLK. See Common Control Register 1 and Figure 1-3. JTAG Reset JTAG Mode Select JTAG Clock JTAG Data In JTAG Data Out Voltage Supply Mode (LQFP only). VSM should be wired low for correct operation. 3.3V, ±5% Transmitter Positive Supply 3.3V, ±5% Positive Supply 12 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface PIN TVSS1–TVSS4 VSS1–VSS4 I/O — — FUNCTION Transmitter Signal Ground for Transmitter Outputs Signal Ground Note 1: G.703 requires an accuracy of ±50ppm for T1 and E1. TR62411 and ANSI specs require ±32ppm accuracy for T1 interfaces. 3. DETAILED DESCRIPTION The DS21448 contains four independent LIUs that share a common interface for configuration and status. The user can choose between three different means of accessing the device: a parallel microprocessor interface, a serial interface, and a hardwired mode, which configures the device by setting levels on the device’s pins. The DS21448’s four chip selects (CS1, CS2, CS3, and CS4) determine which LIU is accessed when using the parallel or serial interface modes. Four sets of identical register maps exist, one for each channel. Using the appropriate chip select accesses a channel’s register map. The analog AMI/HDB3 waveform off the E1 line or the AMI/B8ZS waveform off the T1 line is transformer-coupled into the RTIP and RRING pins of the DS21448. The user has the option to use internal termination, software selectable for 75W/100W/120W applications, or external termination. The device recovers clock and data from the analog signal and passes it through the jitter attenuation mux, outputting the received line clock at RCLK and bipolar or NRZ data at RPOS and RNEG. The DS21448 contains an active filter that reconstructs the analogreceived signal for the nonlinear losses that occur in transmission. The receive circuitry is also configurable for various monitor applications. The device has a usable receive sensitivity of 0 to -43dB for E1 and 0 to -36dB for T1 that allows the device to operate on 0.63mm (22AWG) cables up to 2.5km (E1) and 6k feet (T1) in length. Data input at TPOS and TNEG is sent through the jitter attenuation mux to the waveshaping circuitry and line driver. The DS21448 drives the E1 or T1 line from the TTIP and TRING pins through a coupling transformer. The line driver can handle both CEPT 30/ISDN-PRI lines for E1 and long-haul (CSU) or short-haul (DSX-1) lines for T1. 3.1 DS21448 and DS21Q348 Differences The DS21448 BGA is a monolithic quad-port LIU that is a replacement for the DS21Q348. The additional features of JTAG, transmit driver disable, and the serial interface in the DS21448 have changed the function of several pins, as shown in Table 3-A. Table 3-A. DS21448 vs. DS21Q348 Pin Differences PIN G4 J1 K1 K3 K7 L3 M3 M5 M6 M7 DS21Q348 VSM VSS A4 VSS TEST N.C. N.C. N.C. N.C. N.C. DS21448 N.C. SCLK A4/SDO SDI TXDIS/TEST JTRST* JTMS* JTCLK JTDI* JTDO *DS21448 pin is internally pulled up. 4. PORT OPERATION 4.1 Hardware Mode The DS21448 supports a hardware configuration mode that allows the user to configure the device by setting levels on the device’s pins. This mode allows the DS21448 configuration without the use of a microprocessor, simplifying designs. Not all of the device features are supported in the hardware mode. In hardware mode (BIS0 = 1, BIS1 = 1) several pins have been redefined so they can be used for initializing the DS21448. Refer to Table 2-B and Table 2-E for pin assignment and definition. Because of limited pin count, several 13 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface functions have been combined and affect all four channels in the device and/or treat the receive and transmit paths as one block. Restrictions when using the hardware mode include the following: · · · · · · · · · BPCLK pins only output a 16.384MHz signal. The RCL/LOTC pins are designated to RCL. The RHBE and THBE control bits are combined and controlled by HBE. RSCLKE and TSCLKE bits are combined and controlled by SCLKE. TCES and RCES are combined and controlled by CES. The transmitter functions are combined and controlled by TX1 and TX0. Loopback functions are controlled by LOOP1 and LOOP0. JABDS defaults to 128-bit buffer depth. All other control bits default to logic 0. Table 4-A. Loopback Control in Hardware Mode LOOPBACK Remote Loopback Local Loopback Analog Loopback No Loopback SYMBOL RLB LLB ALB — LOOP1 1 1 0 0 LOOP0 1 0 1 0 Table 4-B. Transmit Data Control in Hardware Mode TRANSMIT DATA Unframed All Ones Alternating Ones and Zeros PRBS TPOS and TNEG SYMBOL TUA1 TAOZ TPRBSE — TX1 1 1 0 0 TX0 1 0 1 0 Table 4-C. Receive Sensitivity Settings in Hardware Mode EGL 0 1 1 0 ETS 0 (E1) 0 (E1) 1 (T1) 1 (T1) RECEIVE SENSITIVITY (dB) -12 (short haul) -43 (long haul) -30 (limited long haul) -36 (long haul) Table 4-D. Monitor Gain Settings in Hardware Mode MM1 0 0 1 1 MM0 0 1 0 1 INTERNAL LINEAR GAIN BOOST (dB) Normal operation (no boost) 20 26 32 Table 4-E. Internal Rx Termination Select in Hardware Mode RT1 RT0 0 0 1 1 0 1 0 1 INTERNAL RECEIVE TERMINATION CONFIGURATION Internal receive-side termination disabled Internal receive-side 120Ω enabled Internal receive-side 100Ω enabled Internal receive-side 75Ω enabled Table 4-F. MCLK Selection in Hardware Mode MCLK (MHz) 2.048 2.048 1.544 JAMUX 0 1 0 ETS 0 1 1 14 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface 4.2 Serial Port Operation Setting BIS1 = 1 and BIS0 = 0 enables the serial bus interface on the DS21448 (Table 2-A). Serial port read/write timing is unrelated to the system transmit and receive timing, allowing asynchronous reads or writes by the host. See Section 10 for the AC timing of the serial port. All serial port accesses are LSB first. See Figure 4-1, Figure 4-2, Figure 4-3, Figure 4-4, Figure 4-5, and Figure 4-6 for additional details. A serial bus access requires the use of four signals: serial clock (SCLK), one of the four chip selects (CS), serial data input (SDI), and serial data output (SDO). The DS21448 uses SCLK to sample data that is present on SDI and output data onto SDO. Input clock-edge select (ICES) allows the user to choose which SCLK edge input data is sampled on. Output clock-edge select (OCES) allows the user to choose which SCLK edge output data changes on. When ICES is low, input data is latched on the rising edge of SCLK, and when ICES is high, input data is latched on the falling edge of SCLK. When OCES is low, data is output on the falling edge of SCLK, and when OCES is high, data is output on the rising edge of SCLK. Data is held until the next falling or rising edge of SCLK. All data transfers are initiated by driving the appropriate port’s CS input low and ends with CS going inactive. CS must go inactive between data transfers. See the serial bus timing information in Section 10 for details. All data transfers are terminated if the port’s CS input transitions high. Port control logic is disabled, and SDO is tri-stated when all CS pins are inactive. Reading from or writing to the internal registers requires writing one address/command byte prior to the transferring register data. Two types of serial bus transfers exist, standard and burst. The standard serial bus access always consists of two bytes, an address/command byte that is always supplied by the user on SDI, and a data byte that can either be written to the DS21448 using SDI (write operation) or output by the DS21448 on SDO (read operation). The burst serial bus access consists of a single address/command byte followed either by 22 read or 22 write data bytes. The first bit written (LSB) of the address/command byte specifies whether the access is to be a read (1) or a write (0). The next 5 bits identify the register address. Valid register addresses are 00h through 15h. Bit 7 is reserved and must be set to 0 for proper operation. Bit 8, the last bit (MSB) of the address/command byte, is the burst modeenable bit. When the burst bit is enabled (set to 0) and a READ operation is performed, the DS21448 automatically outputs the contents of registers 00h through 15h sequentially, starting with register address 00h. When the burst bit is enabled and a WRITE operation is performed, data supplied on SDI is sequentially written into the DS21448’s register space starting at address 00h. Burst operation is stopped once address 15h is read or CS goes inactive. For both burst read and burst write transfers, the address/command byte’s register address bits must be set to 0. The user can broadcast register write accesses to multiple ports simultaneously by enabling the desired channels’ chip selects at the same time. However, only one port can be read at a time. Any attempt to read multiple ports simultaneously results in invalid data being returned on SDO. Figure 4-1. Serial Port Operation for Read Access (R = 1) Mode 1 ICES = 1 (SAMPLE SDI ON THE FALLING EDGE OF SCLK) OCES = 1 (UPDATE SDO ON RISING EDGE OF SCLK) SCLK 1 2 3 4 5 6 A1 A2 A3 A4 A5 7 8 9 10 11 12 13 14 15 D0 D1 D2 D3 D4 D5 D6 16 CS SDI 1 (LSB) SDO 0 B (MSB) READ ACCESS ENABLED (LSB) 15 of 60 D7 (MSB) DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 4-2. Serial Port Operation for Read Access (R = 1) Mode 2 ICES = 1 (SAMPLE SDI ON THE FALLING EDGE OF SCLK) OCES = 0 (UPDATE SDO ON FALLING EDGE OF SCLK) SCLK 1 2 3 4 5 6 A1 A2 A3 A4 A5 7 8 9 10 11 12 13 14 15 16 CS SDI 1 0 B (MSB) (LSB) SDO D0 D1 D2 D3 D4 D5 D6 D7 (MSB) (LSB) Figure 4-3. Serial Port Operation for Read Access (R = 1) Mode 3 ICES = 0 (SAMPLE SDI ON THE RISING EDGE OF SCLK) OCES = 0 (UPDATE SDO ON FALLING EDGE OF SCLK) SCLK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 CS SDI A1 1 A2 A3 A4 A5 0 B (MSB) (LSB) SDO D0 D1 D2 D3 D4 D5 D7 D6 (MSB) (LSB) Figure 4-4. Serial Port Operation for Read Access (R = 1) Mode 4 ICES = 0 (SAMPLE SDI ON THE RISING EDGE OF SCLK) OCES = 1 (UPDATE SDO ON RISING EDGE OF SCLK) SCLK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 D0 D1 D2 D3 D4 D5 D6 16 CS SDI 1 (LSB) SDO A1 A2 A3 A4 A5 0 B (MSB) (LSB) 16 of 60 D7 (MSB) DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 4-5. Serial Port Operation for Write Access (R = 0) Modes 1 and 2 ICES = 1 (SAMPLE SDI ON THE FALLING EDGE OF SCLK) SCLK 1 2 3 4 5 6 A1 A2 A3 A4 A5 7 8 9 10 11 12 13 14 15 16 B DO D1 D2 D3 D4 D5 D6 D7 (MSB) (LSB) CS SDI 0 0 (LSB) (MSB) WRITE ACCESS ENABLED SDO Figure 4-6. Serial Port Operation for Write Access (R = 0) Modes 3 and 4 ICES = 0 (SAMPLE SDI ON THE RISING EDGE OF SCLK) SCLK 1 2 3 4 5 6 0 A1 A2 A3 A4 A5 7 8 9 10 11 12 13 14 15 16 CS SDI (LSB) 0 B DO (MSB) (LSB) D1 D2 D3 D4 D5 D6 D7 (MSB) WRITE ACCESS ENABLED SDO 4.3 Parallel Port Operation The option for either multiplexed bus operation (BIS0 = 0) or nonmultiplexed bus operation (BIS0 = 1) is available when using the parallel interface. The DS21448 can operate with either Intel or Motorola bus timing configurations. If the PBTS pin is wired low, Intel timing is selected; if wired high, Motorola timing is selected. All Motorola bus signals are listed in parentheses (). Four sets of identical register maps exist, one for each channel. See Table 4-H for register names and addresses. Use the appropriate chip select (CS1, CS2, CS3, or CS4) to access a channel’s register map. See the timing diagrams in Section 10 for more details. Hardware and serial port modes are not supported when using parallel port operation. 4.3.1 Device Power-Up and Reset The DS21448 resets itself upon power-up, setting all writeable registers to 00h and clearing the status and information registers. CCR3.7 (TUA1) = 0 results in the LIU transmitting unframed all ones. After the power supplies have settled, initialize all control registers to the desired settings, then toggle the LIRST bit (CCR3.2). The DS21448 can at any time be reset to the default settings by bringing HRST low (level triggered) or by powering down and powering up again. 17 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface Table 4-G. Parallel Port Mode Selection PBTS 0 0 1 1 4.3.2 BIS0 0 1 0 1 PROCESSOR Intel Intel Motorola Motorola BUS INTERFACE TYPE Parallel Port Mode (Multiplexed) Parallel Port Mode (Nonmultiplexed) Parallel Port Mode (Multiplexed) Parallel Port Mode (Nonmultiplexed) Register Map Table 4-H shows the typical register map for all four ports. Use the appropriate chip select (CS1, CS2, CS3, or CS4) to access a channel’s register map. Table 4-H. Register Map NAME CCR1 CCR2 CCR3 CCR4 CCR5 CCR6 SR IMR RIR1 RIR2 IBCC TCD1 TCD2 RUPCD1 RUPCD2 RDNCD1 RDNCD2 ECR1 ECR2 TEST1 TEST2 TEST2 — R/W R/W R/W R/W R/W R/W R/W R R/W R R R/W R/W R/W R/W R/W R/W R/W R R R/W R/W R/W — ADDRESS 00h 01h 02h 03h 04h 05h 06h 07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh 10h 11h 12h 13h 14h 15h (Note 1) FUNCTION Common Control Register 1 Common Control Register 2 Common Control Register 3 Common Control Register 4 Common Control Register 5 Common Control Register 6 Status Register Interrupt Mask Register Receive Information Register 1 Receive Information Register 2 In-Band Code Control Register Transmit Code Definition Register 1 Transmit Code Definition Register 2 Receive-Up Code Definition Register 1 Receive-Up Code Definition Register 2 Receive-Down Code Definition Register 1 Receive-Down Code Definition Register 2 Error Count Register 1 Error Count Register 2 Test 1 Test 2 Test 3 — Note 1: Register addresses 16h–1Fh do not exist. 18 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface 4.3.3 Control Registers CCR1 (00H): Common Control Register 1 (MSB) ETS NRZE NAME POSITION ETS CCR1.7 NRZE CCR1.6 RCLA CCR1.5 ECUE CCR1.4 JAMUX CCR1.3 TTOJ CCR1.2 TTOR CCR1.1 LOTCMC CCR1.0 RCLA ECUE JAMUX TTOJ TTOR (LSB) LOTCMC FUNCTION E1/T1 Select 0 = E1 1 = T1 NRZ Enable 0 = bipolar data at RPOS/RNEG and TPOS/TNEG 1 = NRZ data at RPOS and TPOS or TNEG; RNEG outputs a positive-going pulse when the device receives a BPV, CV, or EXZ Receive-Carrier-Loss Alternate Criteria 0 = RCL declared upon 255 (E1) or 192 (T1) consecutive zeros 1 = RCL declared upon 2048 (E1) or 1544 (T1) consecutive zeros Error Counter Update Enable. A 0-to-1 transition forces the next receive clock cycle to load the error counter registers with the latest counts and reset the counters. The user must wait a minimum of two clock cycles (976ns for E1 and 1296ns for T1) before reading the error count registers to allow for a proper update. See Section 6 for details. Jitter Attenuator Clock Mux. Controls the source for JACLK (Figure 1-1). 0 = JACLK sourced from MCLK (2.048MHz or 1.544MHz at MCLK) 1 = JACLK sourced from internal PLL (2.048MHz at MCLK) TCLK to JACLK. Internally connects TCLK to JACLK (Figure 1-3). 0 = disabled 1 = enabled TCLK to RCLK. Internally connects TCLK to RCLK (Figure 1-3). 0 = disabled 1 = enabled Loss-of-Transmit Clock Mux Control. Determines whether the transmit logic should switch to JACLK if the TCLK input should fail to transition (Figure 1-3). 0 = do not switch to JACLK if TCLK stops 1 = switch to JACLK if TCLK stops 19 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface CCR2 (01H): Common Control Register 2 (MSB) RLPIN — NAME POSITION RLPIN CCR2.7 — CCR2.6 SCLD CCR2.5 CLDS CCR2.4 RHBE CCR2.3 THBE CCR2.2 TCES CCR2.1 RCES CCR2.0 SCLD CLDS RHBE THBE TCES (LSB) RCES FUNCTION RCL/LOTC Pin Function Select. Forced to logic 0 in hardware mode. 0 = toggles high during a receive-carrier loss condition 1 = toggles high if TCLK does not transition for at least 5ms Not Assigned. Should be set to 0 when written to. Short Circuit-Limit Disable (ETS = 0). Controls the 50mA (RMS) current limiter. 0 = enable 50mA current limiter 1 = disable 50mA current limiter Custom Line-Driver Select. Setting this bit to 1 redefines the operation of the transmit line driver. When this bit is set to 1 and CCR4.5 = CCR4.6 = CCR4.7 = 0, the device generates a square wave at the TTIP and TRING outputs instead of a normal waveform. When this bit is set to 1 and CCR4.5 = CCR4.6 = CCR4.7 ¹ 0, the device forces TTIP and TRING outputs to become open-drain drivers instead of their normal push-pull operation. This bit should be set to 0 for normal operation of the device. Contact the factory for more details about how to use this bit. Receive HDB3/B8ZS Enable 0 = enable HDB3 (E1)/B8ZS (T1) 1 = disable HDB3 (E1)/B8ZS (T1) Transmit HDB3/B8ZS Enable 0 = enable HDB3 (E1)/B8ZS (T1) 1 = disable HDB3 (E1)/B8ZS (T1) Transmit Clock-Edge Select. Selects which TCLK edge to sample TPOS and TNEG. 0 = sample TPOS and TNEG on falling edge of TCLK 1 = sample TPOS and TNEG on rising edge of TCLK Receive Clock-Edge Select. Selects which RCLK edge to update RPOS and RNEG. 0 = update RPOS and RNEG on rising edge of RCLK 1 = update RPOS and RNEG on falling edge of RCLK 20 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface CCR3 (02H): Common Control Register 3 (MSB) TUA1 ATUA1 NAME POSITION TUA1 CCR3.7 ATUA1 CCR3.6 TAOZ CCR3.5 TPRBSE CCR3.4 TLCE CCR3.3 LIRST CCR3.2 IBPV CCR3.1 IBE CCR3.0 TAOZ TPRBSE TLCE LIRST IBPV (LSB) IBE FUNCTION Transmit Unframed All Ones. The polarity of this bit is set such that the device transmits an allones pattern on power-up or device reset. This bit must be set to 1 to allow the device to transmit data. The transmission of this data pattern is always timed off JACLK (Figure 1-1). 0 = transmit all ones at TTIP and TRING 1 = transmit data normally Automatic Transmit Unframed All Ones. Automatically transmit an unframed all-ones pattern at TTIP and TRING during an RCL condition. 0 = disabled 1 = enabled Transmit Alternate Ones and Zeros. Transmit a …101010… pattern at TTIP and TRING. The transmission of this data pattern is always timed off TCLK. 0 = disabled 1 = enabled 15 Transmit PRBS Enable. Transmit a 2 - 1 (E1) or a QRSS (T1) PRBS at TTIP and TRING. 0 = disabled 1 = enabled Transmit Loop-Code Enable. Enables the transmit side to transmit the loop-up code in the transmit code definition registers (TCD1 and TCD2). See Section 6 for details. 0 = disabled 1 = enabled Line Interface Reset. Setting this bit from 0 to 1 initiates an internal reset that resets the clock recovery state machine and recenters the jitter attenuator. Normally this bit is only toggled on power-up. It must be cleared and set again for a subsequent reset. Insert Bipolar Violation (BPV). A 0-to-1 transition on this bit causes a single bipolar violation to be inserted into the transmit data stream. Once this bit has been toggled from 0 to 1, the device waits for the next occurrence of three consecutive 1s to insert the BPV. This bit must be cleared and set again for a subsequent error to be inserted (Figure 1-3). Insert Bit Error. A 0-to-1 transition on this bit causes a single logic error to be inserted into the transmit data stream. This bit must be cleared and set again for a subsequent error to be inserted (Figure 1-3). CCR4 (03H): Common Control Register 4 (MSB) L2 L1 NAME L2 L1 L0 POSITION CCR4.7 CCR4.6 CCR4.5 EGL CCR4.4 JAS CCR4.3 JABDS CCR4.2 DJA CCR4.1 TPD CCR4.0 L0 EGL JAS JABDS DJA (LSB) TPD FUNCTION Line Build-Out Select Bit 2. Sets the transmitter build-out (Table 7-A for E1, Table 7-B for T1). Line Build Out Select Bit 1. Sets the transmitter build-out (Table 7-A for E1, Table 7-B for T1). Line Build Out Select Bit 0. Sets the transmitter build-out (Table 7-A for E1, Table 7-B for T1). Receive Equalizer Gain Limit. This bit controls the sensitivity of the receive equalizer (Table 4-I). Jitter Attenuator Path Select 0 = place the jitter attenuator on the receive side 1 = place the jitter attenuator on the transmit side Jitter Attenuator Buffer Depth Select 0 = 128 bits 1 = 32 bits (use for delay-sensitive applications) Disable Jitter Attenuator 0 = jitter attenuator enabled 1 = jitter attenuator disabled Transmit Power-Down 0 = normal transmitter operation 1 = powers down the transmitter and tri-states the TTIP and TRING pins 21 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface Table 4-I. Receive Sensitivity Settings EGL (CCR4.4) 0 1 1 0 ETS (CCR1.7) 0 (E1) 0 (E1) 1 (T1) 1 (T1) RECEIVE SENSITIVITY (dB) -12 (short haul) -43 (long haul) -30 (limited long haul) -36 (long haul) CCR5 (04H): Common Control Register 5 (MSB) BPCS1 BPCS0 NAME BPCS1 BPCS0 MM1 MM0 POSITION CCR5.7 CCR5.6 CCR5.5 CCR5.4 RSCLKE CCR5.3 TSCLKE CCR5.2 RT1 RT0 CCR5.1 CCR5.0 MM1 MM0 RSCLKE FUNCTION Backplane Clock Frequency Select 1. See Table 4-J for details. Backplane Clock Frequency Select 0. See Table 4-J for details. Monitor Mode Gain Select 1 (Table 4-K. ) Monitor Mode Gain Select 0. See (Table 4-K. Receive Synchronization Clock Enable 0 = disable 2.048MHz synchronization receive mode 1 = enable 2.048MHz synchronization receive mode Transmit Synchronization Clock Enable 0 = disable 2.048MHz transmit synchronization clock 1 = enable 2.048MHz transmit synchronization clock Receive Termination Select 1. See Table 4-L for details. Receive Termination Select 0. See Table 4-L for details. Table 4-J. Backplane Clock Select BPCS1 (CCR5.7) 0 0 1 1 BPCS0 (CCR5.6) 0 1 0 1 BPCLK FREQUENCY (MHz) 16.384 8.192 4.096 2.048 Table 4-K. Monitor Gain Settings MM1 (CCR5.5) 0 0 1 1 MM0 (CCR5.4) 0 1 0 1 INTERNAL LINEAR GAIN BOOST (dB) Normal operation (no boost) 20 26 32 Table 4-L. Internal Rx Termination Select RT1 (CCR5.1) 0 0 1 1 RT0 (CCR5.0) 0 1 0 1 TSCLKE INTERNAL RECEIVE TERMINATION CONFIGURATION Internal receive-side termination disabled Internal receive-side 120W enabled Internal receive-side 100W enabled Internal receive-side 75W enabled 22 of 60 RT1 (LSB) RT0 DS21448 3.3V T1/E1/J1 Quad Line Interface CCR6 (05H): Common Control Register 6 (MSB) LLB RLB NAME POSITION LLB CCR6.7 RLB CCR6.6 ARLBE CCR6.5 ALB CCR6.4 RJAB CCR6.3 ECRS2 ECRS1 ECRS0 CCR6.2 CCR6.1 CCR6.0 ARLBE ALB RJAB ECRS2 ECRS1 (LSB) ECRS0 FUNCTION Local Loopback. In local loopback, transmit data is looped back to the receive path, passing through the jitter attenuator if it is enabled. Data in the transmit path acts as normal. See Section 6.2 for details. 0 = loopback disabled 1 = loopback enabled Remote Loopback. In remote loopback, data output from the clock/data recovery circuitry is looped back to the transmit path, passing through the jitter attenuator if it is enabled. Data in the receive path acts as normal, while data presented at TPOS and TNEG is ignored. See Section 6.2 for details. 0 = loopback disabled 1 = loopback enabled Automatic Remote Loopback Enable and Reset. When this bit is set high, the device automatically goes into remote loopback when it detects loop-up code programmed into the receive loop-up code definition registers (RUPCD1 and RUPCD2) for a minimum of 5 seconds; it also sets the RIR2.1 status bit. Once it is in an RLB state, the bit remains in this state until it has detected the loop code programmed into the receive loop-down code definition registers (RDNCD1 and RDNCD2) for a minimum of 5 seconds, at which point it forces the device out of RLB and clears RIR2.1. Toggling this bit from 1 to 0 resets the automatic RLB circuitry. The action of the automatic remote loopback circuitry is logically ORed with the RLB (CCR6.6) control bit (i.e., either one can cause a RLB to occur). Analog Loopback. In analog loopback, signals at TTIP and TRING are internally connected to RTIP and RRING. The incoming line signals at RTIP and RRING are ignored. The signals at TTIP and TRING are transmitted as normal. See Section 6.2 for more details. 0 = loopback disabled 1 = loopback enabled RCLK Jitter Attenuator Bypass. This control bit allows the receive-recovered clock and data to bypass the jitter attenuation, while still allowing the BPCLK output to use the jitter attenuator. See Section 7.3 for details. 0 = disabled 1 = enabled Error Count Register Select 2. See Section 6.4 for details. Error Count Register Select 1. See Section 6.4 for details. Error Count Register Select 0. See Section 6.4 for details. 5. STATUS REGISTERS The three registers that contain information about the device’s real-time status are the status register (SR) and receive information registers 1 and 2 (RIR1/RIR2). When a particular event has occurred (or is occurring), the appropriate bit in one of these registers is set to 1. Some bits in SR, RIR1, and RIR2 are latched bits and some are real-time bits (denoted in the following register descriptions). For latched status bits, when an event or an alarm occurs, the bit is set to 1 and remains set until the user reads that bit. The bit is cleared when it is read, and it is not set until the event has occurred again. Two of the latched status bits (RUA1 and RCL) remain set after reading if the alarm is still present. The user always precedes a read of any of the three status registers with a write. The byte written to the register informs the DS21448 which bits the user wishes to read and have cleared. The user writes a byte to one of these registers with a 1 in the bit positions to be read and a 0 in the other bit positions. When a 1 is written to a bit location, that location is updated with the latest information. When a 0 is written to a bit position, that bit position is not updated, and the previous value is held. A write to the status and information registers is immediately followed by a read of the same register. The read result should be logically ANDed with the mask byte that was just written, and this value should be written back into the same register to ensure that bit does indeed clear. This second write step is necessary because the alarms and events in the status registers occur asynchronously with respect to their access through the parallel port. This write-read-write scheme allows an external microcontroller or microprocessor to individually poll certain bits without disturbing the other bits in the register. This operation is key in controlling the DS21448 with higher-order software languages. 23 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface The bits in the SR register have the unique ability to initiate a hardware interrupt through the INT output pin. Each of the alarms and events in the SR can be either masked or unmasked from the interrupt pin through the interrupt mask register (IMR). The interrupts caused by the RCL, RUA1, and LOTC bits in the SR act differently than the interrupts caused by the other status bits in the SR. The RCL, RUA1, and LOTC bits forces the INT pin low whenever they change state (i.e., go active or inactive). The INT pin is allowed to return high (if no other interrupts are present) when the user reads the alarm bit that caused the interrupt to occur, even if the alarm is still present. The other status bits in the SR can force the INT pin low when they are set. The INT pin is allowed to return high (if no other interrupts are present) when the user reads the event bit that caused the interrupt to occur. The host can quickly determine which of the four LIU channels is generating an interrupt by reading one of the unused addresses in the 16h–1Fh range in any LIU channel. See the following LIU channel interrupt status description for additional information. LIU Channel Interrupt Status (MSB) — — NAME N/A N/A N/A N/A POSITION 7 6 5 4 LIU4 3 LIU3 2 LIU2 1 LIU1 0 — — LIU4 LIU3 LIU2 (LSB) LIU1 FUNCTION Not Assigned. Could be any value when read. Not Assigned. Could be any value when read. Not Assigned. Could be any value when read. Not Assigned. Could be any value when read. LIU4 Status Register. A 1 in this bit position indicates that the status register (SR) in channel 4 is asserting an interrupt. LIU3 Status Register. A 1 in this bit position indicates that the status register (SR) in channel 3 is asserting an interrupt. LIU2 Status Register. A 1 in this bit position indicates that the status register (SR) in channel 2 is asserting an interrupt. LIU1 Status Register. A 1 in this bit position indicates that the status register (SR) in channel 1 is asserting an interrupt. SR (06H): Status Register (MSB) LUP NAME LUP (Latched) LDN (Latched) LOTC (Real Time) RUA1 (Latched) RCL (Latched) TCLE (Real Time) TOCD (Real Time) PRBSD (Real Time) LDN POSITION SR.7 SR.6 SR.5 SR.4 SR.3 SR.2 SR.1 SR.0 LOTC RUA1 RCL TCLE TOCD (LSB) PRBSD FUNCTION Loop-Up Code Detected. This bit is set when the loop-up code defined in registers RUPCD1 and RUPCD2 is being received. See Section 6.1 for details. Loop-Down Code Detected. This bit is set when the loop-down code defined in registers RDNCD1 and RDNCD2 is being received. See Section 6.1 for details. Loss-of-Transmit Clock. This bit is set when the TCLK pin has not transitioned for 5ms (±2ms), forcing the LOTC pin high. Receive Unframed All Ones. This bit is set when an unframed all-ones code is received at RRING and RTIP (Table 5-A). Receive Carrier Loss. This bit is set when an RCL condition exists at RRING and RTIP. See (Table 5-A) for details. Transmit Current-Limit Exceeded. This bit is set when the 50mA (RMS) current limiter is activated whether or not the current limiter is enabled. Transmit Open-Circuit Detect. This bit is set when the device detects that the TTIP and TRING outputs are open circuited. 15 PRBS Detect. This bit is set when the receive side detects a 2 - 1 (E1) or a QRSS (T1) pseudorandom bit sequence (PRBS). 24 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface Table 5-A. Received Alarm Criteria ALARM RUA1 E1/T1 E1 RUA1 T1 RCL (Note 1) E1 RCL (Note 1) T1 SET CRITERIA Fewer than two 0s in two frames (512 bits) Over a 3ms window, five or fewer 0s are received. 255 (or 2048) consecutive 0s received (G.775) (Note 2) CLEAR CRITERIA More than two 0s in two frames (512 bits) Over a 3ms window, six or more 0s are received. In 255-bit times, at least 32 1s are received. 14 or more 1s out of 112 possible bit positions are received, starting with the first 1 received. 192 (or 1544) consecutive 0s are received (Note 2) Note 1: RCL is also known as a loss of signal (LOS) or Red Alarm in T1. Note 2: See CCR1.5 for details. IMR (07H): Interrupt Mask Register (MSB) LUP LDN NAME POSITION LUP IMR.7 LDN IMR.6 LOTC IMR.5 RUA1 IMR.4 RCL IMR.3 TCLE IMR.2 TOCD IMR.1 PRBSD IMR.0 LOTC RUA1 RCL TCLE FUNCTION Loop-Up Code Detected 0 = interrupt masked 1 = interrupt enabled Loop-Down Code Detected 0 = interrupt masked 1 = interrupt enabled Loss-of-Transmit Clock 0 = interrupt masked 1 = interrupt enabled Receive Unframed All Ones 0 = interrupt masked 1 = interrupt enabled Receive Carrier Loss 0 = interrupt masked 1 = interrupt enabled Transmit Current-Limiter Exceeded 0 = interrupt masked 1 = interrupt enabled Transmit Open-Circuit Detect 0 = interrupt masked 1 = interrupt enabled PRBS Detection 0 = interrupt masked 1 = interrupt enabled 25 of 60 TOCD (LSB) PRBSD DS21448 3.3V T1/E1/J1 Quad Line Interface RIR1 (08H): Receive Information Register 1 (MSB) ZD 16ZD NAME POSITION ZD (Latched) RIR1.7 16ZD (latched) RIR1.6 HBD (Latched) RIR1.5 RCLC (Latched) RUA1C (Latched) RIR1.4 RIR1.3 JALT (Latched) RIR1.2 N/A N/A RIR1.1 RIR1.0 HBD RCLC RUA1C JALT — (LSB) — FUNCTION Zero Detect. This bit is set when a string of at least four (ETS = 0) or eight (ETS = 1) consecutive 0s (regardless of the length of the string) have been received. This bit is cleared when read. 16 Zero Detect. This is set when at least 16 consecutive 0s (regardless of the length of the string) have been received. This bit is cleared when read. HDB3/B8ZS Word Detect. This is set when an HDB3 (ETS = 0) or B8ZS (ETS = 1) codeword is detected independently of the receive HDB3/B8ZS mode (CCR4.6) being enabled. This bit is cleared when read. It is useful for automatically setting the line coding. RCL Clear. Set when the RCL alarm has met the clear criteria defined in Table 5-A. This bit is cleared when read. Receive Unframed All-Ones Clear. This bit is set when the unframed all-ones signal is no longer detected. This bit is cleared when read (Table 5-A). Jitter Attenuator Limit Trip. This bit is set when the jitter attenuator FIFO reaches within 4 bits of its useful limit. This bit is cleared when read and is useful for debugging jitter attenuation operation. Not Assigned. Could be any value when read. Not Assigned. Could be any value when read. RIR2 (09H): Receive Information Register 2 (MSB) RL3 NAME RL3 (Real Time) RL2 (Real Time) RL1 (Real Time) RL0 (Real Time) N/A N/A RL2 RL1 RL0 — POSITION — ARLB (LSB) SEC FUNCTION RIR2.7 Receive Level Bit 3 (Table 5-B) RIR2.6 Receive Level Bit 2 (Table 5-B) RIR2.5 Receive Level Bit 1 (Table 5-B) RIR2.4 Receive Level Bit 0 (Table 5-B) RIR2.3 RIR2.2 Not Assigned. Could be any value when read. Not Assigned. Could be any value when read. Automatic Remote Loopback Detected. This bit is set to 1 when the automatic remote loopback circuitry has detected the presence of a loop-up code for 5 seconds. It remains set until the automatic RLB circuitry has detected the loop-down code for 5 seconds. See Section 11 for more details. This bit is forced low when the automatic RLB circuitry is disabled (CCR6.5 = 0). One-Second Timer. This bit is set to 1 on one-second boundaries as timed by the device, based on the RCLK. It is cleared when read. ARLB (Real Time) RIR2.1 SEC (Latched) RIR2.0 26 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface Table 5-B. Receive Level Indication RL3 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 RL2 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 RL1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 RL0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 RECEIVE LEVEL (dB) Greater than -2.5 -2.5 to -5.0 -5.0 to -7.5 -7.5 to -10.0 -10.0 to -12.5 -12.5 to -15.0 -15.0 to -17.5 -17.5 to -20.0 -20.0 to -22.5 -22.5 to -25.0 -25.0 to -27.5 -27.5 to -30.0 -30.0 to -32.5 -32.5 to -35.0 -35.0 to -37.5 -37.5 to -40.0 6. DIAGNOSTICS 6.1 In-Band Loop-Code Generation and Detection The DS21448 can generate and detect a repeating bit pattern from 1 to 8 or 16 bits in length. To transmit a pattern, the user loads the pattern into the transmit code definition (TCD1 and TCD2) registers and selects the proper length of the pattern by setting the TC0 and TC1 bits in the in-band code control (IBCC) register. When generating a 1-, 2-, 4-, 8-, or 16-bit pattern, the transmit code registers (TCD1 and TCD2) must be filled with the proper code. Generation of a 1-, 3-, 5-, or 7-bit pattern only requires TCD1 to be filled. Once this is accomplished, the pattern is transmitted, as long as the TLCE control bit (CCR3.3) is enabled. For example, if the user wished to transmit the standard loop-up code for CSUs, which is a repeating pattern of ...10000100001..., then 80h would be loaded into TCD1, and the length would set using TC1 and TC0 in the IBCC register to 5 bits. The DS21448 can detect two separate repeating patterns to allow for a loop-up code and a loop-down code to be detected. The user programs the codes in the receive-up code definition (RUPCD1 and RUPCD2) registers and the receive-down code definition (RDNCD1 and RDNCD2) registers; the length of each pattern is selected through the -2 IBCC register. The DS21448 detects repeating pattern codes with bit-error rates as high as 1 x 10 . The code detector has a nominal integration period of 48ms, so after approximately 48ms of receiving either code, the proper status bit (LUP at SR.7 and LDN at SR.6) is set to 1. Normally codes are sent for a period of 5 seconds. It is recommended that the software poll the DS21448 every 100ms to 1000ms until 5 seconds has elapsed to ensure the code is continuously present. 27 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface IBCC (0AH): In-Band Code Control Register (MSB) TC1 TC0 NAME POSITION TC1 TC0 RUP2 RUP1 RUP0 RDN2 RDN1 RDN0 IBCC.7 IBCC.6 IBCC.5 IBCC.4 IBCC.3 IBCC.2 IBCC.1 IBCC.0 RUP2 RUP1 RUP0 RDN2 FUNCTION Transmit Code Length Definition Bit 1 (Table 6-A) Transmit Code Length Definition Bit 0. (Table 6-A) Receive Up Code Length Definition Bit 2 (Table 6-B) Receive-Up Code Length Definition Bit 1 (Table 6-B) Receive-Up Code Length Definition Bit 0 (Table 6-B) Receive-Down Code Length Definition Bit 2 (Table 6-B) Receive-Down Code Length Definition Bit 1 (Table 6-B) Receive-Down Code Length Definition Bit 0 (Table 6-B) 28 of 60 RDN1 (LSB) RDN0 DS21448 3.3V T1/E1/J1 Quad Line Interface Table 6-A. Transmit Code Length TC1 TC0 0 0 1 1 0 1 0 1 LENGTH SELECTED (BITS) 5 6/3 7 16/8/4/2/1 Table 6-B. Receive Code Length RUP2/RDN2 RUP1/RDN1 RUP0/RDN0 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 LENGTH SELECTED (BITS) 1 2 3 4 5 6 7 16/8 TCD1 (0BH): Transmit Code Definition Register 1 (MSB) C7 NAME C7 C6 C5 C4 C3 C2 C1 C0 C6 POSITION TCD1.7 TCD1.6 TCD1.5 TCD1.4 TCD1.3 TCD1.2 TCD1.1 TCD1.0 C5 C4 C3 C2 C1 (LSB) C0 FUNCTION Transmit Code Definition Bit 7. First bit of the repeating pattern. Transmit Code Definition Bit 6 Transmit Code Definition Bit 5 Transmit Code Definition Bit 4 Transmit Code Definition Bit 3 Transmit Code Definition Bit 2. A don’t care if a 5-bit length is selected. Transmit Code Definition Bit 1. A don’t care if a 5-bit or 6-bit length is selected. Transmit Code Definition Bit 0. A don’t care if a 5-, 6-, or 7-bit length is selected. TCD2 (0CH): Transmit Code Definition Register 2 (MSB) C15 C14 NAME C15 C14 C13 C12 C11 C10 C9 C8 POSITION TCD2.7 TCD2.6 TCD2.5 TCD2.4 TCD2.3 TCD2.2 TCD2.1 TCD2.0 C13 C12 C11 FUNCTION Transmit Code Definition Bit 15 Transmit Code Definition Bit 14 Transmit Code Definition Bit 13 Transmit Code Definition Bit 12 Transmit Code Definition Bit 11 Transmit Code Definition Bit 10 Transmit Code Definition Bit 9 Transmit Code Definition Bit 8 29 of 60 C10 C9 (LSB) C8 DS21448 3.3V T1/E1/J1 Quad Line Interface RUPCD1 (0DH): Receive-Up Code Definition Register 1 (MSB) C7 NAME C7 C6 C5 C4 C3 C2 C1 C0 C6 POSITION RUPCD1.7 RUPCD1.6 RUPCD1.5 RUPCD1.4 RUPCD1.3 RUPCD1.2 RUPCD1.1 RUPCD1.0 C5 C4 C3 C2 C1 (LSB) C0 FUNCTION Receive-Up Code Definition Bit 7. First bit of the repeating pattern. Receive-Up Code Definition Bit 6. A don’t care if a 1-bit length is selected. Receive-Up Code Definition Bit 5. A don’t care if a 1-bit or 2-bit length is selected. Receive-Up Code Definition Bit 4. A don’t care if a 1-bit to 3-bit length is selected. Receive-Up Code Definition Bit 3. A don’t care if a 1-bit to 4-bit length is selected. Receive-Up Code Definition Bit 2. A don’t care if a 1-bit to 5-bit length is selected. Receive-Up Code Definition Bit 1. A don’t care if a 1-bit to 6-bit length is selected. Receive-Up Code Definition Bit 0. A don’t care if a 1-bit to 7-bit length is selected. RUPCD2 (0EH): Receive-Up Code Definition Register 2 (MSB) C15 NAME C15 C14 C13 C12 C11 C10 C9 C8 C14 POSITION RUPCD2.7 RUPCD2.6 RUPCD2.5 RUPCD2.4 RUPCD2.3 RUPCD2.2 RUPCD2.1 RUPCD2.0 C13 C12 C11 C10 C9 (LSB) C8 C2 C1 (LSB) C0 FUNCTION Receive-Up Code Definition Bit 15 Receive-Up Code Definition Bit 14 Receive-Up Code Definition Bit 13 Receive-Up Code Definition Bit 12 Receive-Up Code Definition Bit 11 Receive-Up Code Definition Bit 10 Receive-Up Code Definition Bit 9 Receive-Up Code Definition Bit 8 RDNCD1 (0FH): Receive-Down Code Definition Register 1 (MSB) C7 NAME C7 C6 C5 C4 C3 C2 C1 C0 C6 POSITION RDNCD1.7 RDNCD1.6 RDNCD1.5 RDNCD1.4 RDNCD1.3 RDNCD1.2 RDNCD1.1 RDNCD1.0 C5 C4 C3 FUNCTION Receive-Down Code Definition Bit 7. First bit of the repeating pattern. Receive-Down Code Definition Bit 6. A don’t care if a 1-bit length is selected. Receive-Down Code Definition Bit 5. A don’t care if a 1-bit or 2-bit length is selected. Receive-Down Code Definition Bit 4. A don’t care if a 1-bit to 3-bit length is selected. Receive-Down Code Definition Bit 3. A don’t care if a 1-bit to 4-bit length is selected. Receive-Down Code Definition Bit 2. A don’t care if a 1-bit to 5-bit length is selected. Receive-Down Code Definition Bit 1. A don’t care if a 1-bit to 6-bit length is selected. Receive-Down Code Definition Bit 0. A don’t care if a 1-bit to 7-bit length is selected. RDNCD2 (10H): Receive-Down Code Definition Register 2 (MSB) C15 NAME C15 C14 C13 C12 C11 C10 C9 C8 C14 POSITION RDNCD2.7 RDNCD2.6 RDNCD2.5 RDNCD2.4 RDNCD2.3 RDNCD2.2 RDNCD2.1 RDNCD2.0 C13 C12 C11 FUNCTION Receive-Down Code Definition Bit 15 Receive-Down Code Definition Bit 14 Receive-Down Code Definition Bit 13 Receive-Down Code Definition Bit 12 Receive-Down Code Definition Bit 11 Receive-Down Code Definition Bit 10 Receive-Down Code Definition Bit 9 Receive-Down Code Definition Bit 8 30 of 60 C10 C9 (LSB) C8 DS21448 3.3V T1/E1/J1 Quad Line Interface 6.2 6.2.1 Loopbacks Remote Loopback (RLB) When RLB (CCR6.6) is enabled, the DS21448 is placed into remote loopback. In this loopback, data from the clock/data recovery state machine is looped back to the transmit path, passing through the jitter attenuator if it is enabled. The data at the RPOS and RNEG pins is valid, while data presented at TPOS and TNEG is ignored. See Figure 1-1 for more details. If the automatic RLB enable (CCR6.5) is set to 1, the DS21448 automatically goes into remote loopback when it detects the loop-up code programmed in the receive-up code definition registers (RUPCD1 and RUPCD2) for a minimum of 5 seconds. When the DS21448 detects the loop-down code programmed in the receive loop-down code definition registers (RDNCD1 and RDNCD2) for a minimum of 5 seconds, the DS21448 comes out of remote loopback. Setting ARLBE to 0 can also disable the ARLB. 6.2.2 Local Loopback (LLB) When LLB (CCR6.7) is set to 1, the DS21448 is placed into local loopback. In this loopback, data on the transmit side is transmitted as normal. TCLK and TPOS/TNEG pass through the jitter attenuator (if enabled) and are output at RCLK and RPOS/RNEG. Incoming data from the line at RTIP and RRING is ignored. If transmit unframed all ones (CCR3.7) is set to 1 while in LLB, TTIP and TRING transmit all ones while TCLK and TPOS/TNEG are looped back to RCLK and RPOS/RNEG. See Figure 1-1 for more details. 6.2.3 Analog Loopback (LLB) Setting ALB (CCR6.4) to 1 puts the DS21448 in analog loopback. Signals at TTIP and TRING are internally connected to RTIP and RRING. The incoming signals at RTIP and RRING are ignored. The signals at TTIP and TRING are transmitted as normal. See Figure 1-1 for more details. 6.2.4 Dual Loopback (DLB) Setting CCR6.7 and CCR6.6 (LLB and RLB, respectively) to 1 puts the DS21448 into dual loopback operation. The TCLK and TPOS/TNEG signals are looped back through the jitter attenuator (if enabled) and output at RCLK and RPOS/RNEG. Clock and data recovered from RTIP and RRING are looped back to the transmit side and output at TTIP and TRING. This mode of operation is not available when implementing hardware operation. See Figure 1-1 more details. 6.3 PRBS Generation and Detection 15 Setting TPRBSE (CCR3.4) = 1 enables the DS21448 to transmit a 2 - 1 (E1) or a QRSS (T1) PRBS, depending on the ETS bit setting in CCR1.7. The DS21448’s receive side always searches for these PRBS patterns independently of CCR3.4. The PRBS bit-error output (PBEO) remains high until the receiver has synchronized to one of the two patterns (64 bits received without an error), at which time PBEO goes low, and the PRBSD bit in the SR is set. Once synchronized, any bit errors received cause a positive-going pulse at PBEO, synchronous with RCLK. This output can be used with external circuitry track bit-error rates during the PRBS testing. Setting CCR6.2 (ECRS2) = 1 allows the PRBS errors to be accumulated in the 16-bit counter in registers ECR1 and ECR2. The PRBS synchronizer remains in sync until it experiences six bit errors or more within a 64-bit span. Both PRBS patterns comply with the ITU-T O.151 specifications. 6.4 Error Counter Error count register 1 (ECR1) is the most significant word and ECR2 is the least significant word of a userselectable 16-bit counter that records incoming errors, including BPVs, code violations (CVs), excessive zero violations (EXZs), and/or PRBS errors. See Table 6-C, Table 6-D, and Figure 1-2 for details. 31 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface Table 6-C. Definition of Received Errors ERROR E1 OR T1 BPV E1/T1 CV E1 EXZ E1 EXZ T1 PRBS E1/T1 DEFINITION OF RECEIVED ERRORS Two consecutive marks with the same polarity. Ignores BPVs because of HDB3 and B8ZS zero suppression when CCR2.3 = 0. Typically used with AMI coding (CCR2.3 = 1). ITU-T O.161. When HDB3 is enabled (CCR2.3 = 0) and the receiver detects two consecutive BPVs with the same polarity. ITU-T O.161. When four or more consecutive zeros are detected. When receiving AMI-coded signals (CCR2.3 = 1), detection of 16 or more 0s or a BPV. ANSI T1.403 1999. When receiving B8ZS-coded signals (CCR2.3 = 0), detection of eight or more 0s or a BPV. ANSI T1.403 1999. A bit error in a received PRBS pattern. See Section 6.3 for details. ITU-T O.151. Table 6-D. Function of ECRS Bits and RNEG Pin E1 or T1 (CCR1.7) 0 0 0 0 1 1 1 1 X ECRS2 (CCR6.2) 0 0 0 0 0 0 0 0 1 ECRS1 (CCR6.1) 0 0 1 1 X X X X X ECRS0 (CCR6.0) 0 1 0 1 0 1 0 1 X RHBE (CCR2.3) X X X X 0 0 1 1 X FUNCTION OF ECR COUNTERS/RNEG (Note 1) CVs BPVs (HDB3 codewords not counted) CVs + EXZs BPVs + EXZs BPVs (B8ZS codewords not counted) BPVs + 8 EXZs BPVs BPVs + 16 EXZs PRBS Errors (Note 2) Note 1: RNEG outputs error data only when in NRZ mode (CCR1.6 = 1). Note 2: PRBS errors are always output at PBEO, independent of ECR control bits and NRZ mode, and are not present at RNEG. 6.5 Error Counter Update A 0-to-1 transition of the ECUE (CCR1.4) control bit updates the ECR registers with the current values and resets the counters. ECUE must be set back to 0 and another 0-to-1 transition must occur for subsequent reads/resets of the ECR registers. Note that the DS21448 can report errors at RNEG when in NRZ mode (CCR1.6 = 1) by outputting a pulse for each error occurrence. The counter saturates at 65,535 and does not roll over. ECR1 (11H): Upper Error Count Register 1/ECR2 (12H): Lower Error Count Register 2 (MSB) E15 E7 NAME E15 E0 6.6 E14 E6 POSITION ECR1.7 ECR2.0 E13 E5 E12 E4 E11 E3 E10 E2 E9 E1 (LSB) E8 E0 ECR1 ECR2 FUNCTION MSB of the 16-bit error count. LSB of the 16-bit error count. Error Insertion When IBPV (CCR3.1) is transitioned from 0 to 1, the device waits for the next occurrence of three consecutive 1s to insert a BPV. IBPV must be cleared and set again for another BPV error insertion. See Figure 1-3 for details on the insertion of the BPV into the data stream. When IBE (CCR3.0) is transitioned from 0 to 1, the device inserts a logic error. IBE must be cleared and set again for another logic error insertion. See Figure 1-2 and Figure 1-3 for details about the logic error insertion into the data steam. 32 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface 7. ANALOG INTERFACE 7.1 Receiver The DS21448 contains a digital clock recovery system. The DS21448 couples to the receive E1 or T1 twisted pair (or coaxial cable in 75W E1 applications) through a 1:1 transformer. See Table 7-C for transformer details. Figure 7-1, Figure 7-2, Figure 7-3, and Table 4-L show the receive termination requirements. The DS21448 has the option of using internal termination resistors. The DS21448 is designed to be fully software selectable for E1 and T1 without the need to change any external resistors for the receive side. The receive side allows user configuration for 75W, 100W, or 120W receive termination by setting the RT1 (CCR5.1) and RT0 (CCR5.0) bits. When using the internal termination feature, the Rr resistors should be 60W each. See Figure 7-1 for details. If external termination is required, RT1 and RT0 should be set to 0, and both Rr resistors (Figure 7-1) should be 37.5W, 50W, or 60W each, depending on the line impedance. The resultant E1 or T1 clock derived from the 2.048/1.544 PLL (JACLK in Figure 1-1) is internally multiplied by 16 through another internal PLL and fed to the clock recovery system. The clock recovery system uses the clock from the PLL circuit to form a 16-times oversampler used to recover the clock and data. This oversampling technique offers outstanding performance to meet jitter tolerance specifications, as shown in Figure 7-7. Normally, the clock that is output at the RCLK pin is the recovered clock from the E1 AMI/HDB3 or T1 AMI/B8ZS waveform presented at the RTIP and RRING inputs. When no signal is present at RTIP and RRING, an RCL condition occurs, and the RCLK is derived from the JACLK source. See Figure 1-1 for more details. If the jitter attenuator is placed in the receive path (as is the case in most applications), the jitter attenuator restores the RCLK to an approximate 50% duty cycle. If the jitter attenuator is either placed in the transmit path or is disabled, the RCLK output can exhibit slightly shorter high cycles of the clock. This is because of the highly oversampled digital clock recovery circuitry. See the receive-side AC timing characteristics in Section 10 for more details. The receive-side circuitry also contains a clock synthesizer that outputs a user-configurable clock (up to 16.384MHz) synthesized from RCLK at BPCLK (pin 31). See Table 4-J for details about output clock frequencies at BPCLK. In hardware mode, BPCLK defaults to a 16.384MHz output. The DS21448 has a bypass mode for the receive-side clock and data. This allows the BPCLK to be derived from RCLK after the jitter attenuator, while the clock and data presented at RCLK, RPOS, and RNEG go unaltered. This is intended for applications where the receive-side jitter attenuation is done after the LIU. Setting RJAB (CCR6.3) to logic 1 enables the bypass. Ensure the jitter attenuator is in the receive path (CCR4.3 = 0). See Figure 1-1 for more details. The DS21448 reports the signal strength at RTIP and RRING in 2.5dB increments through RL3–RL0 located in the receive information register 2. This feature is helpful when troubleshooting line performance problems (Table 5-B). E1 and T1 monitor applications require various flat-gain settings for the receive-side circuitry. The DS21448 can be programmed to support these applications through the monitor mode control bits MM1 and MM0. When the monitor modes are enabled, the receiver tolerates normal line loss up to -6dB (Table 4-K). 7.2 Transmitter The DS21448 uses a set of laser-trimmed delay lines with a precision digital-to-analog converter (DAC) to create the waveforms that are transmitted onto the E1 or T1 line. The waveforms meet the latest ETSI, ITU, ANSI, and AT&T specifications. The user selects which waveform to generate by setting the ETS bit (CCR1.7) for E1 or T1 operation, then programming the L2/L1/L0 bits in common control register 4 for the appropriate application. See Table 7-A and Table 7-B for the proper L2/L1/L0 settings. A 2.048MHz or 1.544MHz TTL clock is required at TCLK for transmitting data at TPOS and TNEG. ITU specification G.703 requires ±50ppm accuracy for T1 and E1. TR62411 and ANSI specs require ±32ppm accuracy for T1 interfaces. The clock can be sourced internally by RCLK or JACLK. See CCR1.2, CCR1.1, CCR1.0, and Figure 1-3 for details. Because of the transmitter’s design, very little jitter (less than 0.005UIP-P broadband from 33 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface 10Hz to 100kHz) is added to the jitter present on TCLK. Also, the waveforms created are independent of the duty cycle of TCLK. The transmitter couples to the E1 or T1 transmit-twisted pair (or coaxial cable in some E1 applications) through a 1:2 step-up transformer. For the device to create the proper waveforms, the transformer used must meet the specifications listed in Table 7-C. The DS21448 has an automatic short-circuit limiter that limits the source current to 50mA (RMS) into a 1Ω load. This feature can be disabled by setting the SCLD bit (CCR2.5) = 1. When the current limiter is activated, TCLE (SR.2) is set even if the short-circuit limiter is disabled. The TPD bit (CCR4.0) powers down the transmit-line driver and tri-states the TTIP and TRING pins. The DS21448 can also detect when the TTIP or TRING outputs are open circuited. When an open circuit is detected, TOCD (SR.1) is set. 7.3 Jitter Attenuator The DS21448 contains an on-board jitter attenuator that can be set to a depth of either 32 or 128 bits through the JABDS bit (CCR4.2). The 128-bit mode is used in applications where large excursions of wander are expected. The 32-bit mode is used in delay-sensitive applications. Figure 7-8 shows the attenuation characteristics. The jitter attenuator can be placed in either the receive path or the transmit path by appropriately setting or clearing the JAS bit (CCR4.3). Also, setting the DJA bit (CCR4.1) can disable the jitter attenuator (in effect, remove it). For the jitter attenuator to operate properly, a 2.048MHz or 1.544MHz clock must be applied at MCLK. ITU specification G.703 requires ±50ppm accuracy for T1 and E1. TR62411 and ANSI specs require ±32ppm accuracy for T1 interfaces. An on-board PLL for the jitter attenuator converts the 2.048MHz clock to a 1.544MHz rate for T1 applications. Setting JAMUX (CCR1.3) to logic 0 bypasses this PLL. On-board circuitry adjusts either the recovered clock from the clock/data recovery block or the clock applied at the TCLK pin to create a smooth jitter-free clock, which is used to clock data out of the jitter attenuator FIFO. It is acceptable to provide a gapped/bursty clock at the TCLK pin if the jitter attenuator is placed on the transmit side. If the incoming jitter exceeds either 120UIP-P (buffer depth is 128 bits) or 28UIP-P (buffer depth is 32 bits), the DS21448 divides the internal nominal 32.768MHz (E1) or 24.704MHz (T1) clock by either 15 or 17 instead of the normal 16 to keep the buffer from overflowing. When the device divides by either 15 or 17, it also sets the JALT bit in the receive information register 1 (RIR1). 7.4 G.703 Synchronization Signal The DS21448 can receive a 2.048MHz square-wave synchronization clock, as specified in Section 10 of ITU G.703. To use the DS21448 in this mode, set the receive-synchronization-clock enable (CCR5.3) = 1. The DS21448 can also transmit the 2.048MHz square-wave synchronization clock, as specified in Section 10 of G.703. To transmit the 2.048MHz clock, set the transmit-synchronization-clock enable (CCR5.2) = 1. Table 7-A. Line Build-Out Select for E1 in Register CCR4 (ETS = 0) L2 0 0 1 1 L1 0 0 0 0 L0 0 1 0 1 APPLICATION 75W normal 120W normal 75W with high return loss 120W with high return loss N 1:2 1:2 1:2 1:2 RETURN LOSS N.M. N.M. 21dB 21dB Rt (W) 0 0 6.2 11.6 Table 7-B. Line Build-Out Select for T1 in Register CCR4 (ETS = 1) L2 0 0 0 0 1 1 1 1 L1 0 0 1 1 0 0 1 1 L0 0 1 0 1 0 1 0 1 APPLICATION DSX-1 (0 to 133ft)/0dB CSU DSX-1 (133 to 266f) DSX-1 (266 to 399ft) DSX-1 (399 to 533ft) DSX-1 (533 to 655ft) -7.5dB CSU -15dB CSU -22.5dB CSU N 1:2 1:2 1:2 1:2 1:2 1:2 1:2 1:2 Note: See Figure 7-1, Figure 7-2, and Figure 7-3. N.M. = Not meaningful. 34 of 60 RETURN LOSS N.M. N.M. N.M. N.M. N.M. N.M. N.M. N.M. Rt (W) 0 0 0 0 0 0 0 0 DS21448 3.3V T1/E1/J1 Quad Line Interface Table 7-C. Line Build-Out Select for E1 in Register CCR4 (ETS = 0) Using Alternate Transformer Configuration L2 0 0 1 1 L1 0 0 0 0 L0 0 1 0 1 APPLICATION 75W normal 120W normal 75W with high return loss 120W with high return loss N 0.8:1:1CT 0.8:1:1CT 0.8:1:1CT 0.8:1:1CT RETURN LOSS N.M. N.M. 21dB 21dB Note: See Figure 7-4. Table 7-D. Transformer Specifications (3.3V Operation) SPECIFICATION Turns Ratio Primary Inductance Leakage Inductance Interwinding Capacitance TRANSMIT TRANSFORMER DC RESISTANCE Primary (Device Side) Secondary RECEIVE TRANSFORMER DC RESISTANCE Primary (Device Side) Secondary RECOMMENDED VALUE 1:1 (receive) and 1:2 (transmit) ±2% 600mH (min) 1.0mH (max) 40pF (max) 1.0W (max) 1.5W (max) 1.2W (max) 1.2W (max) 35 of 60 Rt (W) 0 0 11.6 11.6 DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 7-1. Basic Interface VDD Rt TRANSMIT LINE TTIP VDD TRING VSS 0.1mF 1.0mF (NONPOLARIZED) 2:1 + 0.01mF Rt 0.01mF Dallas Semiconductor (LARGER WINDING TOWARD THE NETWORK) DS21448 VDD 0.1mF RTIP 10mF VSS RECEIVE LINE RRING 1:1 Rr Rr MCLK 2.048MHz (THIS CAN ALSO BE 1.544MHz FOR T1 ONLY OPERATION) 0.1mF NOTE 1: ALL RESISTOR VALUES ARE ±1%. NOTE 2: IN E1 APPLICATIONS, THE RT RESISTORS ARE USED TO INCREASE THE TRANSMITTER RETURN LOSS (Table 7-A). NO RETURN LOSS IS REQUIRED FOR T1 APPLICATIONS. NOTE 3: THE RR RESISTORS SHOULD EACH BE SET TO 60W IF THE INTERNAL RECEIVE-SIDE TERMINATION FEATURE IS ENABLED. WHEN THIS FEATURE IS DISABLED, RR = 37.5W FOR 75W OR 60W FOR 120W E1 SYSTEMS, OR 50W FOR 100W T1 LINES. NOTE 4: SEE Table 7-A AND Table 7-B FOR THE APPROPRIATE TRANSMIT TRANSFORMER TURNS RATIO (N). 36 of 60 68mF DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 7-2. Protected Interface Using Internal Receive Termination VDD Rt FUSE S TRANSMIT LINE S TRING VSS 0.1mF (NONPOLARIZED) Rt 2:1 VDD 1.0mF S S FUSE TTIP Dallas Semiconductor (LARGER WINDING TOWARD THE NETWORK) + 0.01mF 0.01mF DS21448 VDD 0.1mF FUSE RTIP 10mF VSS S RECEIVE LINE S S S FUSE RRING 1:1 60 60 MCLK 2.048MHz (THIS CAN ALSO BE 1.544MHz FOR T1 ONLY OPERATION) 0.1mF NOTE 1: ALL RESISTOR VALUES ARE ±1%. NOTE 2: S IS A SIDACTOR. NOTE 3: THE FUSES ARE OPTIONAL TO PREVENT AC POWER LINE CROSSES FROM COMPROMISING THE TRANSFORMERS. NOTE 4: THE RT RESISTORS ARE USED TO INCREASE THE TRANSMITTER RETURN LOSS (Table 7-A). NO RETURN LOSS IS REQUIRED FOR T1 APPLICATIONS. NOTE 5: THE 68mF IS USED TO KEEP THE LOCAL POWER PLANE POTENTIAL WITHIN TOLERANCE DURING A SURGE. NOTE 6: REFER TO APPLICATION NOTE 324 FOR SIDACTOR AND FUSE DETAILS. 37 of 60 68mF DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 7-3. Protected Interface Using External Receive Termination VDD Rt FUSE TRANSMIT LINE S S VDD TRING VSS 0.1mF 1.0mF S S FUSE TTIP (NONPOLARIZED) Rt 2:1 Dallas Semiconductor DS21448 VDD (LARGER WINDING TOWARD THE NETWORK) + 0.01mF 0.01mF 0.1mF 470 FUSE RTIP 68mF 10mF VSS S RECEIVE LINE S S S FUSE RRING 470 1:1 Rr Rr MCLK 2.048MHz (THIS CAN ALSO BE 1.544MHz FOR T1 ONLY OPERATION) 0.1mF NOTE 1: ALL RESISTOR VALUES ARE ±1%. NOTE 2: S IS A SIDACTOR. NOTE 3: THE FUSES ARE OPTIONAL TO PREVENT AC POWER LINE CROSSES FROM COMPROMISING THE TRANSFORMERS. NOTE 4: Rr = 37.5W FOR 75W OR 60W FOR 120W E1 SYSTEMS, OR 50W FOR 100W T1 LINES. NOTE 5: THE RT RESISTORS ARE USED TO INCREASE THE TRANSMITTER RETURN LOSS (Table 7-A). NO RETURN LOSS IS REQUIRED FOR T1 APPLICATIONS. NOTE 6: THE 68mF IS USED TO KEEP THE LOCAL POWER PLANE POTENTIAL WITHIN TOLERANCE DURING A SURGE. NOTE 7: REFER TO APPLICATION NOTE 324 FOR SIDACTOR AND FUSE DETAILS. 38 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 7-4. Dual Connector-Protected Interface Using Receive Termination 0.22mF FUSE UNBALANCED LINE (75W) 0.8:1:1CT 1.6:1 S VDD TTIP L1 FUSE 1.0mF 0.22mF Rt S S 2:1 S BALANCED LINE (100W/120W) 0.1mF VDD VSS S TRING FUSE 0.01mF 0.01mF + 68mF Rt 0.22mF FUSE VDD 0.8:1:1CT 0.1mF 10mF RTIP UNBALANCED LINE (75W) VSS 0.8:1 S Dallas Semiconductor DS21448 51.1 S L1 FUSE 0.22mF MCLK S BALANCED LINE (100W/120W) S 1:1 2.048MHz (THIS CAN ALSO BE 1.544MHz FOR T1 ONLY OPERATION) S RRING FUSE 60 60 0.1mF NOTE 1: REFER TO APPLICATION NOTE 384 FOR A COMPLETE DISCUSSION OF THIS CIRCUIT. NOTE 2: ALL RESISTOR VALUES ARE ±1%. NOTE 3: THE FUSES ARE OPTIONAL TO PREVENT AC POWER LINE CROSSES FROM COMPROMISING THE TRANSFORMERS. NOTE 4: S IS A SIDACTOR. NOTE 5: THE RT RESISTORS ARE USED TO INCREASE THE TRANSMITTER RETURN LOSS (Table 7-C). NO RETURN LOSS IS REQUIRED FOR T1 APPLICATIONS. NOTE 6: THE 68mF IS USED TO KEEP THE LOCAL POWER PLANE POTENTIAL WITHIN TOLERANCE DURING A SURGE. 39 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 7-5. E1 Transmit Pulse Template (IN 75W SYSTEMS, 1.0 ON THE SCALE = 2.37VPEAK in 120Ω SYSTEMS, 1.0 ON THE SCALE = 3.00VPEAK) SCALED AMPLITUDE 1.2 1.1 269ns 1.0 0.9 0.8 0.7 G.703 TEMPLATE 194ns 0.6 0.5 219ns 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -250 -200 -150 -100 -50 0 TIME (ns) 40 of 60 50 100 150 200 250 DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 7-6. T1 Transmit Pulse Template 1.2 MAXIMUM CURVE UI Time Amp. 1.1 1.0 -0.77 -0.39 -0.27 -0.27 -0.12 0.00 0.27 0.35 0.93 1.16 0.9 0.8 NORMALIZED AMPLITUDE 0.7 0.6 -500 -255 -175 -175 -75 0 175 225 600 750 0.05 0.05 0.80 1.15 1.15 1.05 1.05 -0.07 0.05 0.05 0.5 MINIMUM CURVE UI Time Amp. -0.77 -0.23 -0.23 -0.15 0.00 0.15 0.23 0.23 0.46 0.66 0.93 1.16 -500 -150 -150 -100 0 100 150 150 300 430 600 750 -0.05 -0.05 0.50 0.95 0.95 0.90 0.50 -0.45 -0.45 -0.20 -0.05 -0.05 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 T1.102/87, T1.403, CB 119 (OCT ‘79), AND I.431 TEMPLATE -0.4 -0.5 -500 -400 -300 -200 -100 0 100 200 TIME (ns) 41 of 60 300 400 500 600 700 DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 7-7. Jitter Tolerance UNIT INTERVALS (UIP-P) 1k 100 TR 62411 (DEC ‘90) DS21448 TOLERANCE 10 ITU-T G.823 1 0.1 1 10 100 1k 10k 100k FREQUENCY (Hz) Figure 7-8. Jitter Attenuation JITTER ATTENUATION (dB) 0 TBR12 PROHIBITED AREA ITU G.7XX PROHIBITED AREA -20 CURVE A E1 T1 TR 62411 (DEC 90) PROHIBITED AREA -40 CURVE B -60 1 10 100 1k FREQUENCY (Hz) 42 of 60 10k 100k DS21448 3.3V T1/E1/J1 Quad Line Interface 8. JTAG BOUNDARY SCAN ARCHITECTURE AND TEST ACCESS PORT The DS21448 IEEE 1149.1 design supports the standard instruction codes SAMPLE/PRELOAD, BYPASS, and EXTEST. Optional public instructions included are HIGHZ, CLAMP, and IDCODE (Table 8-A). The DS21448 contains the following items, which meet the requirements set by the IEEE 1149.1 Standard Test Access Port (TAP) and Boundary Scan Architecture: Test Access Port TAP Controller Instruction Register Bypass Register Boundary Scan Register Device Identification Register The TAP has the necessary interface pins JTRST, JTCLK, JTMS, JTDI, and JTDO. See the pin descriptions in Section 1 for details. Details on Boundary Scan Architecture and the Test Access Port can be found in IEEE 1149.1-1990, IEEE 1149.1a-1993, and IEEE 1149.1b-1994. Figure 8-1. JTAG Block Diagram BOUNDRY SCAN REGISTER IDENTIFICATION REGISTER MUX BYPASS REGISTER INSTRUCTION REGISTER TEST ACCESS PORT CONTROLLER VDD 10kW JTDI 8.1 OUTPUT ENABLE VDD VDD 10kW SELECT 10kW JTMS JTCLK JTRST JTDO JTAG TAP Controller State Machine This section covers the operation of the TAP controller state machine. See Figure 8-2 for details on each of the states described below. The TAP controller is a finite state machine that responds to the logic level at JTMS on the rising edge of JTCLK (Table 8-B). Test-Logic-Reset. Upon power-up, the TAP controller is in test-logic-reset state. The instruction register contains the IDCODE instruction. All system logic of the device operates normally. Run-Test-Idle. The run-test-idle is used between scan operations or during specific tests. The instruction register and test registers remain idle. Select-DR-Scan. All test registers retain their previous state. With JTMS LOW, a rising edge of JTCLK moves the controller into the capture-DR state and initiates a scan sequence. JTMS HIGH during a rising edge on JTCLK moves the controller to the select-IR-scan state. 43 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 8-2. TAP Controller State Diagram 1 Test Logic Reset 0 0 Run Test/ Idle 1 Select DR-Scan 1 Select IR-Scan 0 1 0 1 Capture DR Capture IR 0 Shift DR 0 Shift IR 0 1 Exit DR Exit IR Exit2 DR Pause IR 0 1 0 0 1 0 Exit2 IR 1 Update DR 1 0 1 0 0 1 1 0 Pause DR 1 1 Update IR 1 0 Capture-DR. Data can be parallel-loaded into the test data registers selected by the current instruction. If the instruction does not call for a parallel load or the selected register does not allow parallel loads, the test register remains at its current value. On the rising edge of JTCLK, the controller goes to the shift-DR state if JTMS is LOW, or it goes to the exit1-DR state if JTMS is HIGH. Shift-DR. The test data register selected by the current instruction is connected between JTDI and JTDO, and shifts data one stage toward its serial output on each rising edge of JTCLK. If a test register selected by the current instruction is not placed in the serial path, it maintains its previous state. Exit1-DR. While in this state, a rising edge on JTCLK puts the controller in the update-DR state, which terminates the scanning process, if JTMS is HIGH. A rising edge on JTCLK with JTMS LOW puts the controller in the pauseDR state. Pause-DR. Shifting of the test registers is halted while in this state. All test registers selected by the current instruction retain their previous state. The controller remains in this state while JTMS is LOW. A rising edge on JTCLK with JTMS HIGH puts the controller in the exit2-DR state. Exit2-DR. A rising edge on JTCLK with JTMS HIGH while in this state puts the controller in the update-DR state and terminates the scanning process. A rising edge on JTCLK with JTMS LOW enters the shift-DR state. Update-DR. A falling edge on JTCLK while in the update-DR state latches the data from the shift register path of the test registers into the data output latches. This prevents changes at the parallel output due to changes in the shift register. 44 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface Select-IR-Scan. All test registers retain their previous state. The instruction register remains unchanged during this state. With JTMS LOW, a rising edge on JTCLK moves the controller into the capture-IR state and initiates a scan sequence for the instruction register. JTMS HIGH during a rising edge on JTCLK puts the controller back into the test-logic-reset state. Capture-IR. The capture-IR state is used to load the shift register in the instruction register with a fixed value. This value is loaded on the rising edge of JTCLK. If JTMS is HIGH on the rising edge of JTCLK, the controller enters the exit1-IR state. If JTMS is LOW on the rising edge of JTCLK, the controller enters the shift-IR state. Shift-IR. In this state, the shift register in the instruction register is connected between JTDI and JTDO and shifts data one stage for every rising edge of JTCLK toward the serial output. The parallel register and all test registers remain at their previous states. A rising edge on JTCLK with JTMS HIGH moves the controller to the exit1-IR state. A rising edge on JTCLK with JTMS LOW keeps the controller in the shift-IR state while moving data one stage through the instruction shift register. Exit1-IR. A rising edge on JTCLK with JTMS LOW puts the controller in the pause-IR state. If JTMS is HIGH on the rising edge of JTCLK, the controller enters the update-IR state and terminates the scanning process. Pause-IR. Shifting of the instruction shift register is halted temporarily. With JTMS HIGH, a rising edge on JTCLK puts the controller in the exit2-IR state. The controller remains in the pause-IR state if JTMS is LOW during a rising edge on JTCLK. Exit2-IR. A rising edge on JTCLK with JTMS HIGH puts the controller in the update-IR state. The controller loops back to shift-IR if JTMS is LOW during a rising edge of JTCLK in this state. Update-IR. The instruction code shifted into the instruction shift register is latched into the parallel output on the falling edge of JTCLK as the controller enters this state. Once latched, this instruction becomes the current instruction. A rising edge on JTCLK with JTMS LOW puts the controller in the run-test-idle state. With JTMS HIGH, the controller enters the select-DR-scan state. 8.2 Instruction Register The instruction register contains a shift register, as well as a latched parallel output, and is 3 bits in length. When the TAP controller enters the shift-IR state, the instruction shift register is connected between JTDI and JTDO. While in the shift-IR state, a rising edge on JTCLK with JTMS LOW shifts the data one stage toward the serial output at JTDO. A rising edge on JTCLK in the exit1-IR state or the exit2-IR state with JTMS HIGH moves the controller to the update-IR state. The falling edge of that same JTCLK latches the data in the instruction shift register to the instruction parallel output. Table 8-A shows the instructions supported by the DS21448 and its respective operational binary codes. Table 8-A. Instruction Codes for IEEE 1149.1 Architecture INSTRUCTION SAMPLE/PRELOAD BYPASS EXTEST CLAMP HIGHZ IDCODE SELECTED REGISTER Boundary Scan Bypass Boundary Scan Bypass Bypass Device Identification INSTRUCTION CODES 010 111 000 011 100 001 SAMPLE/PRELOAD. This is a mandatory instruction for the IEEE 1149.1 specification that supports two functions. The digital I/Os of the device can be sampled at the boundary scan register without interfering with the normal operation of the device by using the capture-DR state. SAMPLE/PRELOAD also allows the device to shift data into the boundary scan register through JTDI using the shift-DR state. BYPASS. When the BYPASS instruction is latched into the parallel instruction register, JTDI connects to JTDO through the 1-bit bypass test register. This allows data to pass from JTDI to JTDO without affecting the device’s normal operation. 45 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface EXTEST. This allows testing of all interconnections to the device. When the EXTEST instruction is latched in the instruction register, the following actions occur. Once enabled through the update-IR state, the parallel outputs of all digital output pins are driven. The boundary scan register is connected between JTDI and JTDO. The captureDR samples all digital inputs into the boundary scan register. CLAMP. All digital outputs of the device are output data from the boundary scan parallel output while connecting the bypass register between JTDI and JTDO. The outputs do not change during the CLAMP instruction. HIGHZ. All digital outputs of the device are placed in a high-impedance state. The BYPASS register is connected between JTDI and JTDO. IDCODE. When the IDCODE instruction is latched into the parallel instruction register, the identification test register is selected. The device identification code is loaded into the identification register on the rising edge of JTCLK following entry into the capture-DR state. Shift-DR can be used to shift the identification code out serially through JTDO. During test-logic-reset, the identification code is forced into the instruction register’s parallel output. The ID code always has a 1 in the LSB position. The next 11 bits identify the manufacturer’s JEDEC number and number of continuation bytes followed by 16 bits for the device and 4 bits for the version Table 8-B. Table 8-C lists the device ID code for the SCT devices. Table 8-B. ID Code Structure MSB LSB Version (Contact Factory) 4 bits Device ID JEDEC 1 16 bits 00010100001 1 Table 8-C. Device ID Codes DEVICE DS21448 8.3 16-BIT ID 0018 Test Registers IEEE 1149.1 requires a minimum of two test registers—the bypass register and the boundary scan register. An optional test register, the identification register, has been included with the DS21448 design. It is used with the IDCODE instruction and the test-logic-reset state of the TAP controller. Bypass Register The bypass register is a single 1-bit shift register used with the BYPASS, CLAMP, and HIGHZ instructions that provides a short path between JTDI and JTDO. Identification Register The identification register contains a 32-bit shift register and a 32-bit latched parallel output. This register is selected during the IDCODE instruction and when the TAP controller is in the test-logic-reset state. See Table 8-B and Table 8-C for more information about bit usage. Boundary Scan Register The boundary scan register contains a shift register path and a latched parallel output for all control cells and digital I/O cells, and is n bits in length. See Table 8-D for all cell bit locations and definitions. 46 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface Table 8-D. Boundary Scan Control Bits BIT PIN NAME BIT I/O — BGA A1 LQFP 124 RTIP1 I — A2 6 TTIP1 O — A4 28 RTIP2 I — A5 38 TTIP2 O — A7 60 RTIP3 I — A8 71 TTIP3 O — A10 93 RTIP4 I — A11 102 TTIP4 O — B2 125 RRING1 I — B3 9 TRING1 O — B5 29 RRING2 I — B6 41 TRING2 O — B8 61 RRING3 I — B9 74 TRING3 O — B11 94 RRING4 I — B12 105 TRING4 O — D1 39 TVSS2 — — D2 40 TVDD2 — 64 D3 57 CS2 I 48 D4 80 D2/AD2 I/O 46 D5 82 D0/AD0 I/O 67 D6 47 BPCLK2 O 22 D7 128 RCL/LOTC2 O — D8 49–51 VDD3 — — D9 52–54 VSS3 — 44 D10 84 CS3 I 15 D11 14 RPOS3 O 3 D12 34 TNEG3 I 17 E1 12 RPOS2 O PIN BGA NAME I/O BUScntl — I LQFP 54 (Note 1) 56 G12 66 A0 42 H1 92 WR (R/W) I 8 H2 27 TNEG1 I 23 H3 127 RCLK1 O — 26 H4 122 BPCLK1 O — H9 88–90 VSS4 — 52 H10 76 D6/AD6 I/O 58 H11 64 A2 I 57 H12 65 A1 I 2 J1 35 SCLK I 43 J2 91 RD (DS) I 11 J3 18 CS1 I — J4 7 TVSS1 — — J5 8 TVDD1 — 33 J6 109 MCLK I 20 J7 2 RCL/LOTC4 O — J8 85–87 VDD4 — 50 J9 78 D4/AD4 I/O 53 J10 75 D7/AD7 I/O 60 K1 62 A4 I 41 K2 95 ALE (AS) I 1 K3 36 SDI I 19 K4 10 RPOS1 O 32 K5 110 PBEO1 O 37 K7 98 TXDIS/TEST I K8 123 PBEO4 O INTcntl — I/O 16 E2 13 RNEG2 O 25 39 (Note 2) 38 K9 97 INT 49 E3 79 D3/AD3 I/O 28 K10 114 CS4 I K11 16 RPOS4 O I — — E4 19–21 VDD2 — 13 — E9 72 TVSS3 — 62 K12 59 TNEG4 27 E10 121 PBEO3 O 59 L1 63 A3 I 63 E11 58 RCLK3 O 0 L2 43 TCLK2 I 4 E12 33 TPOS3 I — L3 42 JTRST I L5 115–117 VDD1 — O 6 F1 31 RCLK2 O — 7 F2 30 TPOS2 I 24 L6 126 RCL/LOTC1 47 F3 81 D1/AD1 I/O 35 L7 107 BIS0 I — F4 22–24 VSS2 — 30 L8 112 BPCLK4 O 21 F9 1 RCL/LOTC3 O 36 L9 106 HRST I 65 F10 56 BPCLK3 O — L10 103 TVSS4 — 14 F11 15 RNEG3 O 40 L11 96 RCLK4 O 45 F12 83 TCLK3 I 29 L12 113 TCLK4 I 9 G1 26 TPOS1 I 5 M1 32 TNEG2 I O 12 M2 17 TCLK1 I 18 G2 11 RNEG1 31 G3 111 PBEO2 O — M3 48 JTMS I — G9 73 TVDD3 — — M4 118–120 VSS1 — 51 G11 77 D5/AD5 I/O — M5 44 JTCLK I 47 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface BIT PIN — BGA M6 LQFP 45 — M7 46 NAME BIT I/O PIN JTDI I 10 BGA M10 JTDO O 61 — NAME I/O LQFP 25 RNEG4 O — ADRScntl — 55 M8 68 BIS1 I 66 M11 55 TPOS4 I — M9 104 TVDD4 — 34 M12 108 PBTS I Note 1: 0 = Dn/ADn are inputs; 1 = Dn/ADn are outputs. Note 2: 0 = INT is an input; 1 = INT is an output. 9. OPERATING PARAMETERS ABSOLUTE MAXIMUM RATINGS Voltage on Any Pin Relative to Ground Operating Temperature for DS21448TN Storage Temperature -1.0V to +6.0V -40°C to +85°C See IPC/JEDEC J-STD-020A Specification Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to the absolute maximum rating conditions for extended periods may affect device. RECOMMENDED DC OPERATING CONDITIONS (TA = -40°C to +85°C) PARAMETER Logic 1 Logic 0 Supply for 3.3V Operation SYMBOL VIH VIL VDD CONDITIONS MIN 2.2 -0.3 3.135 TYP CONDITIONS MIN CONDITIONS (Note 2) (Note 3) MIN -1.0 (Note 1) MAX 5.5 +0.8 3.465 UNITS V V V TYP 5 7 MAX UNITS pF pF TYP MAX +1.0 +1.0 320 1.06 400 1.32 UNITS mA mA mA mA mA W 3.3 CAPACITANCE (TA = +25°C) PARAMETER Input Capacitance Output Capacitance SYMBOL CIN COUT DC CHARACTERISTICS (VDD = 3.3V ±5%, TA = -40°C to +85°C.) PARAMETER SYMBOL Input Leakage IIL Output Leakage ILO Output Current (2.4V) IOH Output Current (0.4V) IOL Supply Current at 3.3V IDD Power Dissipation at 3.3V PDD -1.0 +4.0 (Notes 4, 5) (Notes 4, 5) Note 1: Applies to VDD. Note 2: 0.0V < VIN < VDD. Note 3: Applied to INT when tri-stated. Note 4: TCLK = MCLK = 2.048MHz. Note 5: Power dissipation with all ports active, TTIP and TRING driving a 30W load, for an all-ones data density. 48 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface 10. AC TIMING PARAMETERS AND DIAGRAMS Table 10-A. AC Characteristics—Multiplexed Parallel Port (BIS0 = 0) (VDD = 3.3V ±5%, TA = -40°C to +85°C.) (Figure 10-1, Figure 10-2, and Figure 10-3) PARAMETER SYMBOL CONDITIONS MIN Cycle Time tCYC 200 100 PW EL Pulse Width, DS Low or RD High 100 PW EH Pulse Width, DS High or RD Low Input Rise/Fall Times tR, tF 10 tRWH R/W Hold Time 50 tRWS R/W Setup Time Before DS High tCS 20 CS Setup Time Before DS, WR, or RD Active 0 tCH CS Hold Time Read Data Hold Time tDHR 10 Write Data Hold Time tDHW 5 Muxed Address Valid to AS or ALE Fall tASL 15 Muxed Address Hold Time tAHL 10 20 tASD Delay Time DS, WR, or RD to AS or ALE Rise Pulse Width AS or ALE High PW ASH 30 10 tASED Delay Time, AS or ALE to DS, WR, or RD 20 tDDR Output Data Delay Time from DS or RD Data Setup Time tDSW 50 TYP MAX 20 50 80 Figure 10-1. Intel Bus Read Timing (PBTS = 0, BIS0 = 0) t CYC ALE WR PWASH t ASD t ASD t ASED RD PWEL PWEH t CH t CS CS t ASL t DDR AD0–AD7 t AHL 49 of 60 t DHR UNITS ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 10-2. Intel Bus Write Timing (PBTS = 0, BIS0 = 0) t CYC ALE RD PWASH t ASD t ASED t ASD WR PWEH t CH t CS PWEL CS t ASL t DHW AD0–AD7 t AHL t DSW Figure 10-3. Motorola Bus Timing (PBTS = 1, BIS0 = 0) PWASH AS DS PWEH t ASED t ASD PWEL t CYC t RWS t RWH R/W AD0–AD7 (READ) t DDR t ASL t AHL t DHR t CH t CS CS AD0–AD7 (WRITE) t DSW t ASL t DHW t AHL 50 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface Table 10-B. AC Characteristics—Nonmultiplexed Parallel Port (BIS0 = 1) (VDD = 3.3V ±5%, TA = -40°C to +85°C.) (Figure 10-4, Figure 10-5, Figure 10-6, and Figure 10-7) PARAMETER SYMBOL CONDITIONS MIN TYP Setup Time for A0 to A4, Valid to CS t1 0 Active Setup Time for CS Active to Either RD, t2 0 WR, or DS Active Delay Time from Either RD or DS Active t3 to Data Valid Hold Time from Either RD, WR, or DS t4 0 Inactive to CS Inactive Hold Time from CS Inactive to Data Bus t5 5.0 Tri-State Wait Time from Either WR or DS Active to t6 75 Latch Data Data Setup Time to Either WR or DS t7 10 Inactive Data Hold Time from Either WR or DS t8 10 Inactive Address Hold from Either WR or DS t9 10 Inactive Figure 10-4. Intel Bus Read Timing (PBTS = 0, BIS0 = 1) ADDRESS VALID A0–A4 D0–D7 DATA VALID 5ns (MIN) / 20ns (MAX) t5 WR t1 0ns (MIN) CS 0ns (MIN) RD t2 t3 75ns (MAX) 51 of 60 t4 0ns (MIN) MAX UNITS ns ns 75 ns ns 20 ns ns ns ns ns DS21448 3.3V T1/E1/J1 Quad Line Interface Figure 10-5. Intel Bus Write Timing (PBTS = 0, BIS0 = 1) ADDRESS VALID A0–A4 D0–D7 t7 t8 10ns (MIN) RD t1 10ns (MIN) 0ns (MIN) CS 0ns (MIN) t2 t6 t4 0ns (MIN) 75ns (MIN) WR Figure 10-6. Motorola Bus Read Timing (PBTS = 1, BIS0 = 1) ADDRESS VALID A0–A4 DATA VALID D0–D7 5ns (MIN) / 20ns (MAX) t5 R/W t1 0ns (MIN) CS 0ns (MIN) t2 t3 t4 0ns (MIN) 75ns (MAX) DS Figure 10-7. Motorola Bus Write Timing (PBTS = 1, BIS0 = 1) ADDRESS VALID A0–A4 D0–D7 10ns (MIN) R/W t1 t7 t8 10ns (MIN) 0ns (MIN) CS 0ns (MIN) DS t2 t6 75ns (MIN) 52 of 60 t4 0ns (MIN) DS21448 3.3V T1/E1/J1 Quad Line Interface Table 10-C. AC Characteristics—Serial Port (BIS1 = 1, BIS0 = 0) (VDD = 3.3V ±5%, TA = -40°C to +85°C.) (Figure 10-8) PARAMETER SYMBOL tCSS Setup Time CS to SCLK Setup Time SDI to SCLK tSSS Hold Time SCLK to SDI tSSH SCLK High/Low Time tSLH SCLK Rise/Fall Time tSRF tLSC SCLK to CS Inactive tCM CS Inactive Time SCLK to SDO Valid tSSV SCLK to SDO Tri-State tSST tCSH CS Inactive to SDO Tri-State CONDITIONS MIN 50 50 50 200 TYP 50 50 250 50 100 100 Figure 10-8. Serial Bus Timing (BIS1 = 1, BIS0 = 0) tCM CS tSRF tCSS tLSC tSLH SCLK (Note 1) SCLK (Note 2) SDI tSSS tSSH LSB tCSH MSB LSB tSSV SDO HIGH-Z MAX LSB NOTE 1: OCES =1 AND ICES = 0. NOTE 2: OCES = 0 AND ICES = 1. 53 of 60 MSB tSST MSB HIGH-Z UNITS ns ns ns ns ns ns ns ns ns ns DS21448 3.3V T1/E1/J1 Quad Line Interface Table 10-D. AC Characteristics—Receive Side (VDD = 3.3V ± 5%, TA =-40°C to +85°C.) (Figure 10-9) PARAMETER SYMBOL RCLK Period tCP tCH tCL tCH tCL RCLK Pulse Width RCLK Pulse Width Delay RCLK to RPOS, RNEG, PBEO, RBPV Valid CONDITIONS (Note 1) (Note 2) MIN (Note 3) 200 ns (Note 4) 150 ns tDD TYP 488 648 MAX ns 50.0 Note 1: E1 mode. Note 2: T1 or J1 mode. Note 3: Jitter attenuator enabled in the receive path. Note 4: Jitter attenuator disabled or enabled in the transmit path. Figure 10-9. Receive-Side Timing RCLK (Note 1) t CL RCLK (Note 2) t CH t CP t DD RPOS, RNEG PBEO BIT ERROR PRBS DETECTOR OUT OF SYNC t DD RNEG (Note 3) BPV/ EXZ/ CV BPV/ EXZ/ CV NOTE 1: RCES = 1 (CCR2.0) OR CES = 1. NOTE 2: RCES = 0 (CCR2.0) OR CES = 0. NOTE 3: RNEG IS IN NRZ MODE (CCR1.6 = 1). 54 of 60 UNITS ns DS21448 3.3V T1/E1/J1 Quad Line Interface Table 10-E. AC Characteristics—Transmit Side (VDD = 3.3V ±5%, TA = -40°C to +85°C.) (Figure 10-10) PARAMETER SYMBOL CONDITIONS (Note 5) TCLK Period tCP (Note 6) tCH TCLK Pulse Width tCL TPOS/TNEG Setup to TCLK tSU Falling or Rising TPOS/TNEG Hold from TCLK tHD Falling or Rising TCLK Rise and Fall Times MIN MAX ns 75 20 ns 20 ns tR, tF 25 Figure 10-10. Transmit-Side Timing t CP t CL tF TCLK (Note 1) TCLK (Note 2) t SU TPOS, TNEG t HD NOTE 1: TCES = 0 (CCR2.1) OR CES = 0. NOTE 2: TCES = 1 (CCR2.1) OR CES = 1. 55 of 60 UNITS ns 75 Note 5: E1 mode. Note 6: T1 or J1 mode. tR TYP 488 648 t CH ns DS21448 3.3V T1/E1/J1 Quad Line Interface 11. PIN CONFIGURATIONS 11.1 144-Pin BGA 1 2 3 4 5 6 7 8 9 10 11 12 A RTIP1 TTIP1 N.C. RTIP2 TTIP2 N.C. RTIP3 TTIP3 N.C. RTIP4 TTIP4 N.C. B N.C. C N.C. N.C. N.C. N.C. N.C. N.C. N.C. N.C. N.C. N.C. D TVSS2 TVDD2 CS2 D2/ AD2 D0/ AD0 BPCLK2 RCL/ LOTC2 VDD3 VSS3 CS3 E RPOS2 RNEG2 D3/ AD3 VDD2 N.C. N.C. N.C. N.C. TVSS3 PEBO3 RCLK3 TPOS3 F RCLK2 TPOS2 D1/ AD1 VSS2 N.C. N.C. N.C. N.C. RCL/ BPCLK3 RNEG3 LOTC3 TCLK3 G TPOS1 RNEG1 PEBO2 N.C. N.C. N.C. N.C. N.C. TVDD3 N.C. D5/ AD5 A0 H WR (R/W) TNEG1 N.C. N.C. N.C. N.C. VSS4 D6/ AD6 A2/ OCES A1 J SCLK RD (DS) CS1 TVSS1 TVDD1 MCLK RCL/ LOTC4 VDD4 D4/ AD4 D7/ AD7 N.C. N.C. K A4/ SDO ALE (AS) SDI RPOS1 PEBO1 N.C. TXDIS/ TEST PEBO4 INT CS4 L A3/ ICES TCLK2 JTRST N.C. VDD1 RCL/ LOTC1 BIS0 BPCLK4 HRST TVSS4 M TNEG2 TCLK1 JTMS VSS1 JTCLK JTDI JTDO BIS1 TVDD4 RRING1 TRING1 N.C. RCLK1 BPCLK1 RRING2 TRING2 56 of 60 N.C. RRING3 TRING3 N.C. RRING4 TRING4 N.C. N.C. RPOS3 TNEG3 RPOS4 TNEG4 RCLK4 TCLK4 RNEG4 TPOS4 PBTS DS21448 3.3V T1/E1/J1 Quad Line Interface TTIP4 N.C. N.C. N.C. TXDIS/TEST INT/ RT1 RCLK4 ALE (AS)/SCLKE RRING4 RTIP4 WR(R/W )/NRZE RD DS)/ETS VSS4 VSS4 VSS4 VDD4 VDD4 VDD4 CS3/EGL3 TCLK3 D0/AD0/MM1 D1/AD1/MM0 D2/AD2/LOOP1 D3/AD3/LOOP0 D4/AD4/TX1 D5/AD5/TX0 D6/AD6/TPD D7/AD7/CES TRING3 TVDD3 TVSS3 TTIP3 N.C. N.C. BIS1 N.C. A0/HBE A1/JAS 11.2 128-Pin LQFP ( TVSS4 TVDD4 TRING4 HRST BIS0 PBTS/RT0 MCLK PBEO1 PBEO2 BPCLK4 TCLK4 CS4/EGL4 VDD1 VDD1 VDD1 VSS1 VSS1 VSS1 PBEO3 BPCLK1 PBEO4 RTIP1 RRING1 RCL1/LOTC1 RCLK1 RCL2/LOTC2 100 90 80 70 60 110 Dallas Semiconductor DS21448 50 120 40 1 10 20 30 TTIP2 N.C. SDI/L1 SCLK/L2 TNEG3 TPOS3 TNEG2 RCLK2 TPOS2 RRING2 RTIP2 TNEG1 TPOS1 RNEG4 VSS2 VSS2 VSS2 VDD2 VDD2 VDD2 CS1/EGL1 TCLK1 RPOS4 RNEG3 RPOS3 RNEG2 RPOS2 RNEG1 RPOS1 TRING1 TVDD1 TVSS1 TTIP1 N.C. N.C. VSM RCL4/LOTC4 RCL3/LOTC3 57 of 60 A2/OCES/JAMUX A3/ICES/DJA A4/SD0/L0 RRING3 RTIP3 TNEG4 RCLK3 CS2/EGL2 BPCLK3 TPOS4 VSS3 VSS3 VSS3 VDD3 VDD3 VDD3 JTMS BPCLK2 JTDO JTDI JTCLK TCLK2 JTRST TRING2 TVDD2 TVSS2 DS21448 3.3V T1/E1/J1 Quad Line Interface 12. PACKAGE INFORMATION (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/DallasPackInfo.) 58 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface PACKAGE INFORMATION (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/DallasPackInfo.) 59 of 60 DS21448 3.3V T1/E1/J1 Quad Line Interface 13. THERMAL INFORMATION Table 13-A. Thermal Characteristics—BGA PARAMETER Ambient Temperature (Note 1) Junction Temperature Theta-JA (qJA) in Still Air (Note 2) MIN -40 TYP MAX +85 +125 UNITS °C °C °C/W MAX +85 +125 UNITS °C °C °C/W °C/W +24 Table 13-B. Theta-JA (qJA) vs. Airflow—BGA FORCED AIR (m/s) 0 1 2.5 THETA-JA (qJA) 24°C/W 21°C/W 19°C/W Table 13-C. Thermal Characteristics—LQFP PARAMETER Ambient Temperature (Note 1) Junction Temperature Theta-JA (qJA) in Still Air (Note 2) Theta-JC (qJC) in Still Air (Note 3) MIN -40 TYP +27.8 +0.1 Table 13-D. Theta-JA (qJA) vs. Airflow—LQFP FORCED AIR (m/s) 0 1 2.5 THETA-JA (qJA) 27.8°C/W 23.5°C/W 21.6°C/W Note 1: The package is mounted on a four-layer JEDEC-standard test board. Note 2: Theta-JA (qJA) is the junction-to-ambient thermal resistance, when the package is mounted on a four-layer JEDEC-standard test board. Note 3: While Theta-JC (qJC) is commonly used as the thermal parameter that provides a correlation between the junction temperature (Tj) and the average temperature on top center of the LQFP package (TC), the proper term is Psi-JT. It is defined by: (Tj - TC) / overall package power. Note 4: The method of measurement for the thermal parameters is defined in the EIA/JEDEC-standard document EIA-JESD51-2. 14. REVISION HISTORY REVISION 042303 DESCRIPTION New product release. Table 5-B. Receive Level Indication: Changed “-12.5 to -5.0” to “-12.5 to -15.0”. Adjusted steps after -17.5 dB to be in -2.5dB decrements. 012104 Section 9, Operating Parameters: Updated supply current and power dissipation values in the DC Characteristics table to reflect latest characterization data. Updated Note 5 to show that values are for all ports active. Maxim/Dallas Semiconductor cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim/Dallas Semiconductor product. No circuit patent licenses are implied. Maxim/Dallas Semiconductor reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2004 Maxim Integrated Products · Printed USA 60 of 60