Hitachi 16-Bit Microcomputer HD64541 Link Layer Controller User’s Manual ADE-602-036A Rev. 2.0 5/26/00 Hitachi, Ltd. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Powered by ICminer.com Electronic-Library Service CopyRight 2003 Cautions 1. Hitachi neither warrants nor grants licenses of any rights of Hitachi’s or any third party’s patent, copyright, trademark, or other intellectual property rights for information contained in this document. Hitachi bears no responsibility for problems that may arise with third party’s rights, including intellectual property rights, in connection with use of the information contained in this document. 2. Products and product specifications may be subject to change without notice. Confirm that you have received the latest product standards or specifications before final design, purchase or use. 3. Hitachi makes every attempt to ensure that its products are of high quality and reliability. However, contact Hitachi’s sales office before using the product in an application that demands especially high quality and reliability or where its failure or malfunction may directly threaten human life or cause risk of bodily injury, such as aerospace, aeronautics, nuclear power, combustion control, transportation, traffic, safety equipment or medical equipment for life support. 4. Design your application so that the product is used within the ranges guaranteed by Hitachi particularly for maximum rating, operating supply voltage range, heat radiation characteristics, installation conditions and other characteristics. Hitachi bears no responsibility for failure or damage when used beyond the guaranteed ranges. Even within the guaranteed ranges, consider normally foreseeable failure rates or failure modes in semiconductor devices and employ systemic measures such as fail-safes, so that the equipment incorporating Hitachi product does not cause bodily injury, fire or other consequential damage due to operation of the Hitachi product. 5. This product is not designed to be radiation resistant. 6. No one is permitted to reproduce or duplicate, in any form, the whole or part of this document without written approval from Hitachi. 7. Contact Hitachi’s sales office for any questions regarding this document or Hitachi semiconductor products. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Powered by ICminer.com Electronic-Library Service CopyRight 2003 Differences between the HD64541 and HD64541S The HD64541 system includes an old HD64541 and new HD64541S. Differences between the HD64541 and HD64541S are shown below. Item HD64541 HD64541S Double frequency mode None Implemented Operating frequency Normal mode: 2.0 MHz to 6.0 MHz Normal mode: 2.0 MHz to 6.25 MHz Double frequency mode: 4.0 MHz to 12.5 MHz 1 2 Package 68-pin plastic PLCC* (CP-68) 80-pin plastic TQFP* (TFP-80C) Process 1.3 µm CMOS 0.8 µm CMOS Notes: 1. PLCC: Plastic leaded chip carrier 2. TQFP: Thin quad flat package Changes in the Revised Edition The following tables list the main differences between this revision and the previous edition (ADE-602-036(0)). The changes are marked with stars ( ) in the text. Changes in the Specifications Specifications Modifications Double frequency mode added HD64541S has the double frequency mode which can operate with a double frequency system clock. Operating frequency The operating frequency of the HD64541S is 2.0 MHz to 6.25 MHz in normal mode 4.0 MHz to 12.5 MHz in double frequency mode Reset command Issuing condition and the operation of Reset command is changed. AC electrical characteristics 16A TFP-80C package added A TFP-80C package has been added to the product lineup. tRHHI is added. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page i of ix Changes in the Text Page Title Modifications 4 1.3 Pin Arrangement Figure for TFP-80C package added 6 1.4 Pin Function Pin numbers for TFP-80C package added Description of double frequency mode added CLKSEL pin added 11 2.1 Operational Outline Description of double frequency mode added 32 2.5.1 System Parameter Table (SYSPT) Description of double frequency mode added 101 5.3.2 AC Electrical characteristics 16A 127 A.15 RSET (Reset) Issuing condition and operation are changed 167 Appendix E Package Dimensions TFP-80C package added 2.0, 05/00, page ii of ix Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library tRHHI added Contents Section 1 1.1 1.2 1.3 1.4 1.5 Description....................................................................................... 1 Description ........................................................................................................................ Block Diagram .................................................................................................................. Pin Arrangement ............................................................................................................... Pin Function ...................................................................................................................... 1.4.1 Power Supply ....................................................................................................... 1.4.2 Address/Data Bus................................................................................................. 1.4.3 System Control..................................................................................................... 1.4.4 DMA Control ....................................................................................................... 1.4.5 Interrupt Control................................................................................................... 1.4.6 Bus Driver Control ............................................................................................... 1.4.7 Bus Exception Conditions.................................................................................... 1.4.8 Area Control......................................................................................................... 1.4.9 Serial Interface ..................................................................................................... 1.4.10 General-Purpose I/O............................................................................................. 1.4.11 Clock .................................................................................................................... 1.4.12 Others ................................................................................................................... System Configuration........................................................................................................ 1 3 4 6 7 7 8 8 8 9 9 9 9 10 10 10 11 Section 2 2.1 2.2 2.3 2.4 2.5 Functional Description .................................................................... 13 Operational Outline ........................................................................................................... Registers ............................................................................................................................ 2.2.1 Command Register............................................................................................... 2.2.2 Command Status Register (CMSR)...................................................................... 2.2.3 Status Register (SR) ............................................................................................. 2.2.4 Interrupt Source Register (ISR)............................................................................ 2.2.5 Interrupt Mask Register (IMR)............................................................................. Commands......................................................................................................................... Status ................................................................................................................................. 2.4.1 Interrupt Method .................................................................................................. 2.4.2 Polling Method..................................................................................................... Tables Implemented In External Memory......................................................................... 2.5.1 System Parameter Table (SYSPT) ....................................................................... 2.5.2 Reject Frame Information Table (REJIT) ............................................................ 2.5.3 Sending I-Frame Information Table (SIIT) .......................................................... 2.5.4 Sending U, X Frame Information Table (SUXIT) ............................................... 2.5.5 Transmit Data Buffer (SDB) ................................................................................ 2.5.6 Receive Buffer Information Table (RBIT)........................................................... 2.5.7 Receive Data Buffer (RDB) ................................................................................. Powered by ICminer.com Electronic-Library Service CopyRight 2003 13 15 16 16 17 18 19 20 26 26 26 32 34 39 43 45 47 47 50 Rev. 2.0, 05/00, page iii of ix 2.5.8 2.5.9 System Parameter Dump Table (SYSDT)............................................................ 50 Statistical Information Logging Table (LOGT) ................................................... 51 Section 3 LAPB Data Link Control Protocol.................................................. 55 3.1 3.2 3.3 3.4 Frame Structure ................................................................................................................. 3.1.1 Flag....................................................................................................................... 3.1.2 Address Field ....................................................................................................... 3.1.3 Control Field ........................................................................................................ 3.1.4 Information Field ................................................................................................. 3.1.5 FCS (Frame Check Sequence) ............................................................................. 3.1.6 Interframe Time Fill ............................................................................................. Frame Type ....................................................................................................................... 3.2.1 I Command (Information) .................................................................................... 3.2.2 SABM Command (Set Asynchronous Balanced Mode) and SABME Command (Set Asynchronous Balanced Mode Extended).................... 3.2.3 DISC Command (Disconnect).............................................................................. 3.2.4 RR Command/Response (Receive Ready) ........................................................... 3.2.5 REJ Command/Response (Reject) ....................................................................... 3.2.6 RNR Command/Response (Receive Not Ready) ................................................. 3.2.7 UA Response (Unnumbered Acknowledgement) ................................................ 3.2.8 DM Response (Disconnected Mode) ................................................................... 3.2.9 FRMR Response (Frame Reject).......................................................................... 3.2.10 UI Command/Response (Unnumbered Information) ........................................... 3.2.11 TEST Command/Response .................................................................................. 3.2.12 XID Command/Response (Exchange Identification) ........................................... Frame Transmission .......................................................................................................... 3.3.1 Bit Transmission Order ........................................................................................ 3.3.2 Invalid Frames...................................................................................................... 3.3.3 Abort (Frame Discard) ......................................................................................... 3.3.4 Transparency ........................................................................................................ System Parameters and State Variables............................................................................. 3.4.1 System Parameters ............................................................................................... 3.4.2 State Variables...................................................................................................... Section 4 4.1 4.2 55 56 57 57 57 58 60 61 61 61 62 62 62 62 63 63 63 64 64 65 65 65 65 65 66 66 66 67 Communication Control Operation................................................. 69 Initialization ...................................................................................................................... 4.1.1 Reset Operation .................................................................................................... 4.1.2 Establishment of Operating Mode........................................................................ Establishment and Release of Logical Link ...................................................................... 4.2.1 Establishing a Logical Link.................................................................................. 4.2.2 Logical Link Release............................................................................................ 4.2.3 Timer T1 Runout.................................................................................................. 4.2.4 Independent Link Disconnection.......................................................................... 2.0, 05/00, page iv of ix Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 69 69 70 73 73 75 75 76 4.3 4.4 4.5 4.6 4.7 4.8 Data Transmit and Receive ............................................................................................... 4.3.1 I-Frame Transmission .......................................................................................... 4.3.2 Transmitting UI, XID, and TEST Frames ............................................................ 4.3.3 Receiving Frames that Contain I-Fields ............................................................... 4.3.4 Transmitting and Receiving I-Frames .................................................................. 4.3.5 Receiving REJ Frames ......................................................................................... 4.3.6 T1 Runout ............................................................................................................ 4.3.7 T3 Runout ............................................................................................................ Link Reset ......................................................................................................................... Exception Condition Handling .......................................................................................... 4.5.1 N(S) Sequence Error ............................................................................................ 4.5.2 N(R) Sequence Error............................................................................................ 4.5.3 Busy States ........................................................................................................... 4.5.4 Receipt of Unexpected Frames............................................................................. 4.5.5 Receipt of I-frame with Invalid N(S) ................................................................... Transparent Mode ............................................................................................................. Protocol mode (T.90, X.75, X.25)..................................................................................... Fast Transfer Speed ........................................................................................................... 4.8.1 Continuous Frame Reception ............................................................................... 4.8.2 Continuous Frame Transmission.......................................................................... 4.8.3 Chain of Data Buffers .......................................................................................... 4.8.4 External Memory and Data DMA Transfer.......................................................... Section 5 5.1 5.2 5.3 5.4 76 76 81 83 86 88 88 88 89 90 90 90 90 91 92 92 96 96 97 97 98 99 Electrical Characteristics .................................................................101 Absolute Maximum Ratings.............................................................................................. 101 Recommended Operating Conditions................................................................................ 101 Electrical Characteristics ................................................................................................... 102 5.3.1 DC Electrical Characteristics ............................................................................... 102 5.3.2 AC Electrical Characteristics ............................................................................... 103 Timing Diagrams............................................................................................................... 107 Appendix A Command Details..........................................................................115 A.1 A.2 A.3 CPOL (Control Peripheral Output Pin Level) ................................................................... 115 A.1.1 Format .................................................................................................................. 115 A.1.2 Function ............................................................................................................... 115 A.1.3 Command Usage .................................................................................................. 115 A.1.4 Description ........................................................................................................... 115 DDR1 (I-Frame Transmission 1)....................................................................................... 116 A.2.1 Format .................................................................................................................. 116 A.2.2 Function ............................................................................................................... 116 A.2.3 Command Usage .................................................................................................. 116 A.2.4 Description ........................................................................................................... 117 DDR2 (I-Frame Transmission 2)....................................................................................... 117 Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page v of ix A.3.1 Format .................................................................................................................. 117 A.3.2 Function ............................................................................................................... 117 A.3.3 Command Usage .................................................................................................. 117 A.3.4 Description ........................................................................................................... 118 A.4 DERC (Dump Statistical Information) .............................................................................. 118 A.4.1 Format .................................................................................................................. 118 A.4.2 Function ............................................................................................................... 118 A.4.3 Command Usage .................................................................................................. 118 A.4.4 Description ........................................................................................................... 118 A.4.5 Note...................................................................................................................... 119 A.5 DESR (Establish Link)...................................................................................................... 119 A.5.1 Format .................................................................................................................. 119 A.5.2 Function ............................................................................................................... 119 A.5.3 Command Usage .................................................................................................. 119 A.5.4 Description ........................................................................................................... 119 A.6 DESW (Remote Station Link Establish Wait)................................................................... 120 A.6.1 Format .................................................................................................................. 120 A.6.2 Function ............................................................................................................... 120 A.6.3 Command Usage .................................................................................................. 120 A.6.4 Description ........................................................................................................... 120 A.7 DRLR (Release Link)........................................................................................................ 121 A.7.1 Format .................................................................................................................. 121 A.7.2 Function ............................................................................................................... 121 A.7.3 Command Usage .................................................................................................. 121 A.7.4 Description ........................................................................................................... 121 A.8 DSPT (Dump System Parameter Table (SYSPT)) ............................................................ 122 A.8.1 Format .................................................................................................................. 122 A.8.2 Function ............................................................................................................... 122 A.8.3 Command Usage .................................................................................................. 122 A.8.4 Description ........................................................................................................... 122 A.9 MPIS (Mask Information from Peripheral Input Pins)...................................................... 123 A.9.1 Format .................................................................................................................. 123 A.9.2 Function ............................................................................................................... 123 A.9.3 Command Usage .................................................................................................. 123 A.9.4 Description ........................................................................................................... 123 A.10 MUDR (U and X Frame Transmission) ............................................................................ 124 A.10.1 Format .................................................................................................................. 124 A.10.2 Function ............................................................................................................... 124 A.10.3 Command Usage .................................................................................................. 124 A.10.4 Description ........................................................................................................... 124 A.11 OMDS (Set Operating Mode) ........................................................................................... 125 A.11.1 Format .................................................................................................................. 125 A.11.2 Function ............................................................................................................... 125 2.0, 05/00, page vi of ix Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library A.12 A.13 A.14 A.15 A.16 A.17 A.18 A.11.3 Command Usage .................................................................................................. 125 A.11.4 Description ........................................................................................................... 125 RESR (Reestablish Link) .................................................................................................. 127 A.12.1 Format .................................................................................................................. 127 A.12.2 Function ............................................................................................................... 127 A.12.3 Command Usage .................................................................................................. 127 A.12.4 Description ........................................................................................................... 127 RETD (Resume Frame Transmission) .............................................................................. 128 A.13.1 Format .................................................................................................................. 128 A.13.2 Function ............................................................................................................... 128 A.13.3 Command Usage .................................................................................................. 128 A.13.4 Description ........................................................................................................... 128 RSBY (Release Local Station from Busy State) ............................................................... 129 A.14.1 Format .................................................................................................................. 129 A.14.2 Function ............................................................................................................... 129 A.14.3 Command Usage .................................................................................................. 129 A.14.4 Description ........................................................................................................... 129 RSET (Reset)..................................................................................................................... 130 A.15.1 Format .................................................................................................................. 130 A.15.2 Function ............................................................................................................... 130 A.15.3 Command Usage .................................................................................................. 130 A.15.4 Description ........................................................................................................... 130 A.15.5 Notes .................................................................................................................... 130 SSBY (Set Local Station to Busy State)............................................................................ 131 A.16.1 Format .................................................................................................................. 131 A.16.2 Function ............................................................................................................... 131 A.16.3 Command Usage .................................................................................................. 131 A.16.4 Description ........................................................................................................... 131 STAC (Set Area Code)...................................................................................................... 132 A.17.1 Format .................................................................................................................. 132 A.17.2 Function ............................................................................................................... 132 A.17.3 Command Usage .................................................................................................. 132 A.17.4 Description ........................................................................................................... 132 A.17.5 Notes .................................................................................................................... 133 SUTD (Suspend Frame Transmission).............................................................................. 133 A.18.1 Format .................................................................................................................. 133 A.18.2 Function ............................................................................................................... 133 A.18.3 Command Usage .................................................................................................. 133 A.18.4 Description ........................................................................................................... 133 Appendix B Status Details.................................................................................134 B.1 ACIF (Verify I-Frame)...................................................................................................... 134 B.1.1 Format .................................................................................................................. 134 Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page vii of ix B.2 B.3 B.4 B.5 B.6 B.7 B.8 B.9 B.10 B.11 B.12 B.13 B.14 B.15 B.1.2 Reporting Function............................................................................................... 134 DESI (Establish Link) ....................................................................................................... 134 B.2.1 Format .................................................................................................................. 134 B.2.2 Reporting Function............................................................................................... 134 DRLI (Release Link) ......................................................................................................... 135 B.3.1 Format .................................................................................................................. 135 B.3.2 Reporting Function............................................................................................... 135 FREC (Receive Frames).................................................................................................... 135 B.4.1 Format .................................................................................................................. 135 B.4.2 Reporting Function............................................................................................... 135 FSYC (Flag Synchronization ) .......................................................................................... 136 B.5.1 Format .................................................................................................................. 136 B.5.2 Reporting Function............................................................................................... 136 IDET (Idle Detection) ....................................................................................................... 136 B.6.1 Format .................................................................................................................. 136 B.6.2 Reporting Function............................................................................................... 136 LRST (Reset Link) ............................................................................................................ 137 B.7 1 Format .................................................................................................................. 137 B.7.2 Reporting Function............................................................................................... 137 PITL (Peripheral Input Pin Level)..................................................................................... 138 B.8.1 Format .................................................................................................................. 138 B.8.2 Reporting Function............................................................................................... 138 RRBY (Remote Station Busy Release) ............................................................................. 140 B.9.1 Format .................................................................................................................. 140 B.9.2 Reporting Function............................................................................................... 140 SRBY (Remote Station Busy) ........................................................................................... 140 B.10.1 Format .................................................................................................................. 140 B.10.2 Reporting Function............................................................................................... 140 SRC1 (System Recovery Request 1) ................................................................................. 141 B.11.1 Format .................................................................................................................. 141 B.11.2 Reporting Function............................................................................................... 141 SRC2 (System Recovery Request 2) ................................................................................. 141 B.12.1 Format .................................................................................................................. 141 B.12.2 Reporting Function............................................................................................... 141 TAIF (Terminate Frame Transmission) ............................................................................ 142 B.13.1 Format .................................................................................................................. 142 B.13.2 Reporting Function............................................................................................... 142 TAUF (Terminate U and X Frame Transmission) ............................................................ 142 B.14.1 Format .................................................................................................................. 142 B.14.2 Reporting Function............................................................................................... 142 YRCV (Remote Station System Recovery Request)......................................................... 143 B.15.1 Format .................................................................................................................. 143 B.15.2 Reporting Function............................................................................................... 143 2.0, 05/00, page viii of ix Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Appendix C Link Layer Protocol Sequence Diagrams .....................................144 Appendix D Link Layer Controller Command Error and Status List ...............165 Appendix E Package Dimensions......................................................................167 Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page ix of ix Powered by ICminer.com Electronic-Library Service CopyRight 2003 Section 1 Description 1.1 Description The HD64541 one-chip CMOS communications device supports T.90, X.75, and X.25 protocols described by CCITT recommendation. Because of its asynchronous bus interface, it can be used with 16-bit external microprocessors. The new HD64541S operates at a higher speed than the old HD64541. The HD64541S also has a very small package to achieve high density mounting. HD64541 features: • CCITT recommendation T.90, X.75, and X.25 support Processes T.90, X.75, and X.25 layer 2 protocols Reduces main processor load, improving system throughput • Protocol processing operations HDLC framing, zero insertion/deletion, flag control, retransmission control, and state transition control • Statistical counters Includes seventeen counters for statistical information: counters for specific frame types transmitted or received, transmission errors, etc. Reports counter status to host processor • Selectable mode and parameters T.90, X.75, and X.25 modes System parameters programmable • Chained transmit/receive function Long frames may be stored in multiple data buffers that are chained together and, except for UI, TEST, and XID frames, may be transmitted or received. Transmitted UI, TEST, and XID frame lengths are limited to a single buffer • High throughput through unique architecture High performance protocol processing and data transmission • Double frequency mode (HD64541S only) The HD64541S is able to operate with a 12.5 MHz system clock in the double frequency mode. • TQFP* package (HD64541S only) The HD64541S has a very small 80-pin TQFP package. 1 Note: TQFP: Thin quad flat package Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 1 of 168 Table 1-1 summarizes HD64541 functions. Table 1-1 HD64541 Function Summary Feature Function Communication protocol CCITT T.90 layer 2/X.25 layer 2 (LAPB)/X.75 layer 2 Line rate (data rate) Max 5 Mbps Number of lines One full duplex line Operation Mode T.90, X.75, X.25 mode Selectable parameters Maximum number of retransmissions: N2 Maximum number of octets in an information field: N1 Maximum time allowed without receiving acknowledgement to transmitted frames (0.1 to 25.5 seconds, 0.1 second steps): T1 Maximum time allowed for idle state (0.1 to 25.5 seconds, 0.1 second steps): T3 or (1 to 255 seconds, 1 second steps) Maximum number of outstanding I frames (1 to 127): K Time for delayed acknowledgement: T2 Diagnostics Auto-echo Local loopback Auto-echo and local loopback Peripheral I/O ports 3 inputs, 2 outputs (general-purpose I/O, level detection) Data encoding NRZ serial data Data transfer with memory DMA Address space 16 Mbyte Data bus width 16 bits (multiplexed with address bus) Power supply Single +5 V Power consumption 130 mW (typ.) Process CMOS 1.3 µm (HD64541) CMOS 0.8 µm (HD64541S) Package 1 68-pin plastic PLCC* (CP-68) (HD64541) 2 80-pin plastic TQFP* (TFP-80C) (HD64541S) Ordering code HD64541C01CP (CP-68) HD64541SC01TF (TFP-80C) Notes: 1. PLCC: Plastic leaded chip carrier 2. TQFP: Thin quad flat package 2.0, 05/00, page 2 of 168 Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 1.2 Block Diagram Figure 1-1 is the HD64541 block diagram. VCC VSS (Clock frequency divider) CLK ÷ IRQ IACK CS Interrupt control unit RAM RES µROM AS Dedicated controller Host register HDS LDS Timer/ counter System interface (Host MPU memory) A 1 –A 3 A 4 –A 7 R/W READY DBEN DIN Bus driver S/U A 8 /D 0 – A 23 /D 15 PF DMA controller RXD RXC Receive channel TXC AIN Line control unit TXD ABEN FIFO receive/ transmit BREQ DMA control unit BACK Transmit channel BRTRY BERR PI0–PI2 PO0–PO1 Figure 1-1 HD64541 Block Diagram Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 3 of 168 1.3 Pin Arrangement Figure 1-2 (a) shows the HD64541 pin arrangement. 60 44 61 43 Index 68 1 9 27 10 26 (Top view) Figure 1-2 (a) HD64541 Pin Arrangement (CP-68) PLCC Pin arrangement Pin No. Names Pin No. Names Pin No. Names Pin No. Names 1 VSS 18 CLK 35 A18/D10 52 PI1 2 VCC 19 A3 36 A19/D11 53 PI2 3 R/: 20 A4 37 A20/D12 54 RXC 4 +'6 21 A5 38 A21/D13 55 RXD 5 /'6 22 A6 39 A22/D14 56 VSS 6 5($'< 23 A7 40 A23/D15 57 VCC 7 $,1 24 A8/D0 41 VSS 58 TXD 8 ,54 25 A9/D1 42 VCC 59 TXC 9 ,$&. 26 A10/D2 43 VCC 60 NUM 10 NC 27 A11/D3 44 %575< 61 %5(4 11 S/8 28 A12/D4 45 %(55 62 %$&. 12 PF 29 A13/D5 46 5(6 63 &6 13 NUM 30 A14/D6 47 NUM 64 $6 14 A1 31 A15/D7 48 NUM 65 $%(1 15 A2 32 A16/D8 49 PO0 66 NC 16 VSS 33 VSS 50 PO1 67 ',1 17 VCC 34 A17/D9 51 PI0 68 '%(1 NUM: Not users mode NC: No connection 2.0, 05/00, page 4 of 168 Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Figure 1-2 (b) shows the HD64541S pin arrangement. 60 41 61 40 80 21 Index 20 1 Figure 1-2 (b) HD64541S Pin Arrangement (TFP-80C) Pin No. Names Pin No. Names Pin No. Names Pin No. Names 1 NC 21 NC 41 NC 61 NC 2 NC 22 A11/D3 42 %575< 62 %5(4 3 S/8 23 A12/D4 43 %(55 63 %$&. 4 PF 24 A13/D5 44 5(6 64 &6 5 CLKSEL 25 A14/D6 45 NUM 65 $6 6 A1 26 A15/D7 46 NUM 66 $%(1 7 A2 27 A16/D8 47 PO0 67 NC 8 VSS 28 VSS 48 PO1 68 ',1 9 NC 29 A17/D9 49 PI0 69 '%(1 10 VCC 30 A18/D10 50 PI1 70 VSS 11 CLK 31 A19/D11 51 PI2 71 NC 12 A3 32 A20/D12 52 RXC 72 VCC 13 A4 33 A21/D13 53 RXD 73 R/: 14 A5 34 A22/D14 54 VSS 74 +'6 15 A6 35 A23/D15 55 NC 75 /'6 16 A7 36 VSS 56 VCC 76 5($'< 17 A8/D0 37 NC 57 TXD 77 $,1 18 A9/D1 38 VCC 58 TXC 78 ,54 19 A10/D2 39 VCC 59 NUM 79 ,$&. 20 NC 40 NC 60 NC 80 NC NUM: Not users mode NC: No connection Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 5 of 168 1.4 Pin Function Table 1-2 describes the pin functions. Table 1-2 Pin Description Pin No. Group Mnemonic CP-68 TFP-80C I/O Function Power supply VCC 2, 17, 42, 43, 57 10, 38, 39, 56, 72 I +5 V power supply VSS 1, 16, 33, 41, 56 8, 28, 36, 54, 70 I 0 V ground A1 to A3 14, 15, 19 6, 7, 12 I/O Address bus A4 to A7 20, 21, 22, 23 13, 14, 15, 16 O Address bus A8/D0 to A23/D15 24 to 32, 34 to 40 17 to 19 22 to 35 I/O Address data bus &6 63 64 I Chip select $6 64 65 I/O Address strobe R/: 3 73 I/O Read/write +'6 4 74 I/O High data strobe /'6 5 75 I/O Low data strobe 5($'< 6 76 I/O Ready %5(4 61 62 O Bus request %$&. 62 63 I Bus acknowledge ,54 8 78 O Interrupt request ,$&. 9 79 I Interrupt acknowledge $%(1 65 66 O Address bus enable $,1 7 77 O Address indication '%(1 68 69 O Data bus enable ',1 67 68 O Data indication %575< 44 42 I Bus cycle retry 5(6 46 44 I Reset %(55 45 43 I Bus error S/8 11 3 O Supervisor/user PF 12 4 O Program fetch Address/data bus System control DMA control Interrupt control Bus control Bus driver control Area control 2.0, 05/00, page 6 of 168 Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Table 1-2 Pin Description (cont) Pin No. Group Mnemonic Serial interface RXD 55 53 I Receive data RXC 54 52 I Receive clock TXD 58 57 O Transmit data TXC 59 58 I Transmit clock PI0 to PI2 51, 52, 53 49, 50, 51 I Port input General-purpose CP-68 TFP-80C I/O Function PO0 to PO1 49, 50 47, 48 O Port output Clock CLK 18 11 I Clock Clock select CLKSEL — 5 I Select the clock mode Others NUM 13, 47, 48, 60 45, 46, 59 I Not user mode NC 10, 66 1, 2, 9, 20, 21, 37, 40, 41, 55, 60, 61, 67, 71, 80 O No connection 1.4.1 Power Supply VCC: Connect VCC to the +5 V power supply. VSS: Connect VSS to ground (0 V). 1.4.2 Address/Data Bus A1 to A3 (Address Bus): When the HD64541 controls the bus, it is said to be in master mode and drives active address pins A1 to A3 as outputs. When the HD64541 is in slave mode, A1 to A3 become inputs and, together with the +'6 and /'6 input pins, address the HD64541’s internal registers. A4 to A7 (Address Bus): In master mode, the HD64541 drives active address pins A4 to A7 as outputs. A8/D0 to A23/D15 (Address/Data Bus): The A8/D0 to A23/D15 pins are time-multiplexed between address and data. Output pins $%(1, $,1, ',1, and '%(1 are used to externally demultiplex data and addresses. In master mode, the HD64541 drives active these pins as outputs to carry both addresses and data. In slave mode, these pins may be either inputs or outputs, but for data only. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 7 of 168 1.4.3 System Control &6 (Chip Select): When the HD64541 does not control the bus, &6 is the chip select input. $6 (Address Strobe): When the HD64541 controls the bus and is outputting address bits A1 to A7 and A8/D0 to A23/D15, the $6 output is active low. When the HD64541 does not control the bus, this line is an input indicating valid address input. R/: : (Read/Write): When the HD64541 is reading the bus, R/: is high. When it is writing to the bus, R/: is low. This controls the direction of data flow. +'6 (High Data Strobe): +'6 indicates the presence of data on the high-order eight bits of the data bus (D15 to D8). In master mode, the HD64541 drives active this signal as an output. In slave mode, the HD64541 reads this bit as an input. /'6 (Low Data Strobe): /'6 indicates the presence of data on the low-order eight bits of the data bus (D7 to D0). In master mode, the HD64541 drives active this signal as an output. In slave mode, the HD64541 reads this bit as an input. 5($'< (Ready): When the HD64541 controls the bus, 5($'< is an input signalling the completion of a data transfer. When the HD64541 releases the bus, 5($'< becomes an output indicating the completion of data read/write. 1.4.4 DMA Control %5(4 (Bus Request): The HD64541 uses %5(4 to request the bus. %$&. (Bus Acknowledge): The %$& input responds to %5(4, indicating that the bus is available. 1.4.5 Interrupt Control ,54 (Interrupt Request): The ,54 output requests an MPU interrupt. It is an open-drain output. ,$&. (Interrupt Acknowledge): The ,$&. input responds to ,54, indicating that the interrupt request has been accepted. The HD64541 then supplies the interrupt vector, whose value was established by VADD (byte 2 of SYSPT) at initialization. 2.0, 05/00, page 8 of 168 Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 1.4.6 Bus Driver Control $%(1 (Address Bus Enable): The $%(1 output latches the address on the address/data lines when the HD64541 controls the bus. $,1 (Address Indication): The $,1 output is asserted while the HD64541 controls the bus. It controls the output of the address line latch. '%(1 (Data Bus Enable): The '%(1 output controls the direction of the bidirectional address data buffer. ',1 (Data Indication): The ',1 output controls the direction of the data lines. 1.4.7 Bus Exception Conditions %575< (Bus Retry): The %575< input requests a bus cycle retry. The retry exception causes the HD64541 to hold the current operation and retry the operation until the retry is removed. 5(6 (Reset): The HD64541 is initialized when 5(6 goes low. It must be held low for at least 24 clock cycles. %(55 (Bus Error): When the HD64541 recognizes a bus error input on %(55, the bus cycle ends and the bus is released. This takes at least 8 clock cycles. 1.4.8 Area Control S/8 8 (Supervisor/User): The S/8 output indicates user-space or supervisor-space access. PF (Program Fetch): The PF output indicates program-space or data-space access. 1.4.9 Serial Interface RXD (Receive Data): Input pin RXD connects to the received data channel. Data bits on RXD are synchronized to the rising edges of the clock pulses on RXC. RXC (Receive Clock): Input pin RXC connects to the synchronous receive data clock. TXD (Transmit Data): Output pin TXD connects to the transmit data channel. Data bits on TXD are synchronized to the falling edges of the clock pulses on TXC. TXC (Transmit Clock): Output pin TXC sources a synchronous transmit data clock. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 9 of 168 1.4.10 General-Purpose I/O PI0 to PI2 (Port Input): PI0 to PI2 are general-purpose input ports whose levels are reported to the external microprocessor by means of PITL status. These ports are independent of the HD64541’s protocol operations. PO0 to PO1 (Port Output): PO0 to PO1 are general-purpose output ports whose levels are controlled by the external microprocessor by means of the CPOL command. These ports are independent of the HD64541’s protocol operations. 1.4.11 Clock CLK (Clock): Input pin CLK connects to the system clock. The frequency of the system clock should be the same frequency for the normal mode, and double the frequency for the double frequency mode, versus the frequency which is specified with TDIV on the system parameter table (SYSTP). (refer 2.5.1) CLKSEL (Clock Select): The CLKSEL input selects the system clock frequency mode. High level input selects the double frequency mode and the CLK input is divided by 2 to use in the chip. Low level input selects the normal mode and the CLK input is directly used in the chip. 1.4.12 Others NUM (Not User Mode): The NUM pins must be connected to logic low. NC (No Connection): Leave NC pins unconnected. 2.0, 05/00, page 10 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 1.5 System Configuration Figure 1-3 is an example of a system configuration using the HD64541. The HD64541 processes the signal received from the line according to protocol procedure. The processed result is sent to the host MPU. Transmit data is transferred to the line according to commands from the host MPU. Layers 3 to 7 Main memory HN27C256 (ROM) HM62256 (RAM) Host MPU 16-bit external microprocessors 8-, 16-bit peripheral LSIs (ACRTC, etc.) Local bus (16-bit data) Layer 2 HD64541 (link layer controller) RXD TXD Figure 1-3 System Configuration Block Diagram Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 11 of 168 2.0, 05/00, page 12 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Section 2 Functional Description 2.1 Operational Outline The HD64541 requires an external microprocessor and memory to operate (figure 2-1). The external microprocessor controls HD64541 operations by writing command codes into the command register (CR). The HD64541 returns the results of command execution or protocol processing through codes made available to the microprocessor through the status register (SR). A command status register (CMSR), interrupt source register (ISR), and interrupt mask register (IMR) complete the microprocessor interface register set. For details, see section 2.2, Registers. For command types and formats, see section 2.3, Commands, and appendix A. For status types and formats, see section 2.4, Status, and appendix B. External memory holds a total of nine control tables (see section 2.5, Tables Implemented in External Memory, for details), including the transmit data buffer (SDB), receive data buffer (RDB), sending I-frame information table (SIIT), receive buffer information table (RBIT), and system parameter table (SYSPT). The HD64541 reads from and writes into the tables on command from the external microprocessor. Double frequency mode (only for HD64541S) The HD64541S can use the internal clock, which is the system clock divided by 2 in the chip. As a result, the HD64541S can operate at 12.5 MHz maximum. The double frequency mode is set by inputting a high level into the CLKSEL pin. However note that the minimum period of each bus cycle is the same in double frequency mode and normal mode, since the maximum internal operating frequency is the same for both modes. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 13 of 168 External microprocessor External memory System parameter table (SYSPT) Transmit data buffer (SDB) Receive data buffer (RDB) Sending I-frame information table (SIIT) Receive buffer information table (RBIT) . . . Control parameters, transmit data, and others Status Microprocessor bus Command Statistical information HD64541 Command register (CR) Status register (SR) Command status register (CMSR) Interrupt source register (ISR) Interrupt mask register (IMR) TXD RXD Figure 2-1 HD64541 External Device Interfaces 2.0, 05/00, page 14 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 2.2 Registers The HD64541 has five registers that can be directly accessed by the external microprocessor through the system bus. 1. Command register (CR) 2. Command status register (CMSR) 3. Status register (SR) 4. Interrupt source register (ISR) 5. Interrupt mask register (IMR) Table 2-1 shows the address assignment of each register. Table 2-1 Register Address Map Address Configuration A3 A2 A1 +'6 /'6 Register R/: : 0 0 0 0 1 0 0 0 1 0 Command W register (CR) — Parameter 1 0 0 1 0 1 — Parameter 2 0 0 1 1 0 — Parameter 3 0 0 0 0 1 $00 Status code 0 0 0 1 0 $00 Parameter 1 Status R register (SR) Reset 7 6 5 4 3 — — — Command code 0 0 1 0 1 $00 Parameter 2 0 0 1 1 0 $00 Parameter 3 0 1 0 0 1 — — — 0 1 0 1 0 Interrupt source reg. (ISR) R/W $00 0 1 1 0 1 — — — 0 1 1 1 0 Interrupt mask reg. (IMR) R/W $3F 1 0 0 0 1 — — — 1 0 0 1 0 Command status reg. (CMSR) R $00 2 1 0 — 0 0 Interrupt source — 0 0 Interrupt mask 0 0 0 — 0 0 Code Note: CR and SR have the same address. CR is accessed by write cycles, and SR is accessed by read cycles. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 15 of 168 2.2.1 Command Register The external microprocessor controls the HD64541 by writing command codes into its command register (figure 2-2). The command register is four octets wide and may be addressed either as four contiguous single-octet registers (CR-HH, CR-HL, CR-LH, and CR-LL) or as two contiguous two-octet registers (CR-H and CR-L). The command register is write-only and shares addresses with the read-only status register. The low order half (CR-L) or quarter (CR-LL) of the command register must be written last since the HD64541 takes that as an indication that the full CR write has been completed. The 7 and 6 bit of CR-HH are don't care bits. When the HD64541 is busy executing a command started earlier, the low-order bit (CMSR0) of the command status register (CMSR) is set to 1 and any attempt to write into the command register (CR) is ignored. 7 6 — — 5 4 3 2 1 0 Command code CR-HH Parameter 1 CR-HL Parameter 2 CR-LH Parameter 3 CR-LL CR-H CR-L Figure 2-2 Command Register 2.2.2 Command Status Register (CMSR) The command status register (figure 2-3) controls writing to the CR and indicates the results of command execution. CMSR0 set to 1 indicates that a command is being executed, and the MPU cannot write another command. The MPU should check the state of CMSR0 before writing to the CR. CMSR1 and CMSR2 are valid when CMSR0 is cleared to 0. They indicate the result of the execution of the previous command. Whenever CMSR0 makes a transition from 1 to 0 (that is, busy to not busy), the low-order bit of the ISR (ISR0) is set to 1 and generates an interrupt unless masked by the IMR. Rev. 2.0, 05/00, page 16 of 168 CMSR 7 6 5 4 3 0 0 0 0 0 2 1 0 0: Space; end of command execution 1: Command is currently being executed 00: Normal end 01: Formatting error 10: Unable to execute Figure 2-3 Command Status Register 2.2.3 Status Register (SR) The HD64541 returns the results of command or protocol processing to the external microprocessor by setting status codes in its status register (figure 2-4). The status register is four octets wide and may be addressed either as four contiguous single-octet registers (SR-HH, SR-HL, SR-LH, and SR-LL) or as two contiguous two-octet registers (SR-H and SR-L). The status register is read-only and shares addresses with the write-only command register. The low-order half (SR-L) or quarter (SR-LL) of the status register must be read last since the HD64541 takes that as an indication that the full SR read has been completed. Status code = $00 shows that the SR does not contain an active status. Whenever the status is set in SR, ISR1 is set to 1. This causes an interrupt if it is not masked by the IMR. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 17 of 168 7 6 5 4 3 2 1 0 Status code SR-HH Parameter 1 SR-HL Parameter 2 SR-LH Parameter 3 SR-LL SR-H SR-L Figure 2-4 Status Register 2.2.4 Interrupt Source Register (ISR) The interrupt source register (figure 2-5) indicates interrupt causes. All bits except ISR4 can be read and written. Table 2-2 shows the function of the ISR bits. To reset any ISR bit, write 1 to that bit. Note that ISR4 cannot be reset by writing to it. It remains high during internal processing. Even though the ISR is masked by the interrupt mask register (IMR), the ISR operates normally. ISR 7 6 0 0 5 4 3 2 See table 2-2 Figure 2-5 Interrupt Source Register 2.0, 05/00, page 18 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 1 0 Table 2-2 ISR Function Bit Name Description ISR0 End of command execution Command was executed; result was written into CMSR; HD64541 ready to accept next command ISR1 End of status write Status written into SR; request that MPU read SR ISR2 Internal queue overflow Internal queue overflow; stop all operations and enter reset command waiting state ISR3 Receive buffer overflow I-, UI, XID ,or TEST frame was lost because the receive buffer was not ready ISR4 Internal busy Entered own receiver busy state (see note) ISR5 DMA bus error Bus error during DMA access; HD64541 enters reset command waiting state Note: The HD64541 enters the internal busy state when it cannot locate the RDB. The external microprocessor remedies this condition by establishing an RDB and setting its address and size into the RBIT. The HD64541 also enters internal busy when an excessive number of status conditions are pending. The external microprocessor must read the SR to clear this condition. Command execution stops temporarily during internal busy. Internal busy state is maintained even after link is reestablished. 2.2.5 Interrupt Mask Register (IMR) The interrupt mask register (figure 2-6) masks interrupt requests. It has the same structure as the ISR. Bits 5 to 0 correspond to ISR bits 5 to 0. The IMR can be read and written to. To mask an interrupt request, set the corresponding bit to 1. The reset command (RSET) sets IMR to $3F (all requests masked). IMR 7 6 0 0 5 4 3 2 1 0 Figure 2-6 Interrupt Mask Register Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 19 of 168 2.3 Commands The external microprocessor controls the HD64541 with the command codes listed in table 2-3. Figure 2-7 shows the command bit encodings. Commands are classified into two types: • Type B: Commands to activate I-, UI, XID, and TEST frame transmission. • Type A: All other commands. Figure 2-8 is a command processing flowchart. Before issuing a command, the external microprocessor must verify that CMSR0 = 0, indicating that the previous command has terminated. If a write to the CR is attempted when CMSR0 = 1, the contents of CR will remain unchanged and the next command will not be accepted. A command format error is posted on three conditions: 1. The command code is undefined. 2. The command is not allowed in the current protocol mode. 3. The command parameters are illegal. The HD64541 sets the CMSR to 00000010 and generates a maskable interrupt request. A correctly formatted command may not be valid under all conditions. Appendix A, which contains a description of every command recognized by the HD64541, specifies the conditions under which each command may be executed and the conditions under which the HD64541 rejects the command with a cannot execute error (CMSR = 00000100) maskable interrupt. After a type A command is executed, the HD64541 sets the CMSR to 00000000. When a type B command is executed to effect I-, UI, XID, or TEST frame transmission, the CMSR may indicate successful completion (CMSR = 00000000) even though the frame is merely queued and actual transmission occurs later, when HD64541 status and the state of the protocol permit. 2.0, 05/00, page 20 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Set Area Code (STAC) Parameter 1 Command code $00 Parameter 2 AC0 Parameter 3 AC1 AC2 Reset (RSET) Parameter 1 Command code $01 Parameter 2 Parameter 3 System parameter table starting address A23 A0 Set Operation Mode (OMDS) Parameter 1 Command code $02 0 0 Parameter 2 Parameter 3 Parameter 2 Parameter 3 0 0 0 M M M 2 1 0 Control Peripheral Output Pin Level (CPOL) Parameter 1 Command code $10 0 0 0 0 0 0 E E 0 0 N N 1 0 0 0 0 0 P P O O 1 0 Mask Peripheral Input Information (MPIS) Parameter 1 Command code $11 Parameter 2 0 0 Parameter 3 0 0 0 P P P I I I 2 1 0 Dump System Parameter Table (DSPT) Parameter 1 Command code $12 Parameter 2 Parameter 3 Dump address A23 A0 Dump Statistical Information (DERC) Parameter 1 Command code $13 Parameter 2 Parameter 3 Dump address A23 A0 I-Frame Transmission 1 (DDR1) Command code Parameter 1 Parameter 2 $20 Parameter 3 P FN I-Frame Transmission 2 (DDR2) Command code Parameter 1 Parameter 2 $21 Parameter 3 P FN Figure 2-7 Commands Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 21 of 168 U and X Frame Transmission (MUDR) Command code Parameter 1 Parameter 2 Parameter 3 Parameter 2 Parameter 3 Parameter 1 Parameter 2 Parameter 3 Parameter 1 Parameter 2 Parameter 3 Parameter 1 Parameter 2 Parameter 3 Parameter 2 Parameter 3 Parameter 2 Parameter 3 Parameter 1 Parameter 2 Parameter 3 Parameter 1 Parameter 2 Parameter 3 $22 Suspend Frame Transmission (SUTD) Command code Parameter 1 $23 Resume Frame Transmission (RETD) Command code $24 Establish Link (DESR) Command code $25 Release Link (DRLR) Command code $26 Set Local Station to Busy State (SSBY) Command code Parameter 1 $27 Release Local Station from Busy State (RSBY) Command code Parameter 1 $28 Remote Station Link Establish Wait (DESW) Command code $29 Reestablish Link (RESR) Command code $2A Figure 2-7 Commands (cont) 2.0, 05/00, page 22 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Table 2-3 Commands Operation Mode Command Symbol Code Parameters Description Set area code STAC $00 AC0, AC1, AC2 Specifies area code (AC) for HD64541 memory access Reset RSET $00 SYSPT starting address Clears internal state, then reads and latches SYSPT saved in external memory Set operation mode OMDS $02 M2-M0 Specifies operating conditions (loopback test, off-line operation, etc.) Control CPOL peripheral output pin level $10 EN1, EN0, PO1, PO0 Sets level of peripheral output pins Mask peripheral MPIS input information $11 PI2-PI0 Masks HD64541 status depending on level of peripheral input pins Dump system DSPT parameter table $12 Dump address Dumps system parameter table to memory area Dump statistical DERC information $13 Dump address Dumps monitor information to external memory I-frame transmission 1 DDR1 $14 P, FN Transmits I-frame data; after link is set, DDR2 is used I-frame transmission 2 DDR2 $21 P, FN Transmits first I-frame after DESI status U and X frame transmission MUDR $22 — Transmits UI , XID and TEST frames Suspend frame SUTD transmission $23 — Temporarily suspends I-, UI, XID, and TEST frame transmission Resume frame transmission RETD $24 — Resumes I-, UI, XID and TEST frame transmission Establish link DESR $25 — Establishes link Powered by ICminer.com Electronic-Library Service CopyRight 2003 Protcol Transparent — — Rev. 2.0, 05/00, page 23 of 168 Table 2-3 Commands (cont) Operation Mode Symbol Code Parameters Description Release link DRLR $26 — Releases link — Set local station SSBY to busy state $27 — Sets local station into busy state — Release local station from busy state RSBY $28 — Releases local station from busy state — Remote station DESW link establish wait $29 — Waits for link establishment from remote station — Reestablish link RESR $2A — Reestablishes link — 2.0, 05/00, page 24 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Protcol Transparent Command Host MPU HD64541 Read CMSR CMSR0 = 0 No Yes Write CR Set CR CMSR0 ← 1 Accept command Yes Formatting error No Yes Cannot execute No Type B Transmit information is queued up , Frame transmission Type A CMSR0 = 010 ISR0 ← 1 Maskable interrupt CMSR0 = 100 ISR0 ← 1 Maskable interrupt Processing execution End CMSR0 = 000 ISR0 ← 1 CMSR0 = 000 ISR0 ← 1 Abnormal processing Abnormal processing ,, , When interrupts are masked, CMSR is polled directly. CMSR7 to CMSR3 should always be low. Maskable interrupt Maskable interrupt Figure 2-8 Command Processing Flow Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 25 of 168 2.4 Status The HD64541 notifies the external microprocessor of the results of command execution or protocol processing by means of status codes passed through the status register (SR). Table 2-4 lists the valid status codes. See appendix B for more details. Interrupt source register bit 1 (ISR1) set to 1 indicates that valid status information is available in the SR. ISR1 = 0 or all zeros in the SR indicate the absence of valid status. Note: When two or more status conditions are pending and an ISR1 = 1 interrupt is generated, the driver software clears ISR1, and reads the SR and processes the status repeatedly until an SR read gets all zeros, indicating no more status. However, because of the HD64541’s internal timing, it is possible for the driver software to read an all-zero SR even though valid status is pending. In this case, the driver software mistakenly concludes that no more status is pending and exits the interrupt. When the HD64541 firmware sets the next status into SR, it also sets ISR1 to 1 to request another status interrupt, so that no pending status conditions are lost. Figure 2-10 is the status read flowchart. Either of two methods may be used by the external microprocessor to read the status: interrupt and polling. 2.4.1 Interrupt Method When interrupt mask register bit 1 (IMR1) = 0, status available interrupts are allowed. When valid status becomes available in the SR, an interrupt request is generated and the interrupt source register bit 1 (ISR1) is set to 1. The interrupt service routine determines that it is a status available interrupt by noting the value of ISR1 and clearing it before reading the SR. (Clearing ISR1 after reading SR may cause additional pending status available interrupts to be lost.) Because multiple status conditions may be stacked up, the interrupt service routine must re-interrogate ISR1 after reading SR to determine if any more are to be read. 2.4.2 Polling Method When interrupt mask register bit 1 (IMR1) = 1, status available interrupts are disabled. The external microprocessor must periodically read the SR to determine whether status is available. In this case the external microprocessor should first read SR-H (or SR-HH) because SRL (or SR-LL) read indicates the completion of the full SR read. All zeros in the SR indicate the absence of status. 2.0, 05/00, page 26 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Establish Link (DESI) Status code Parameter 1 Parameter 2 Parameter 3 Parameter 1 Parameter 2 Parameter 3 Parameter 1 Parameter 2 Parameter 3 Parameter 2 Parameter 3 Parameter 1 Parameter 2 Parameter 3 Parameter 1 Parameter 2 Parameter 3 $01 Release Link (DRLI) Status code $02 Verify I-Frame (ACIF) Status code $03 Indicate Remote Station Busy (SRBY) Status code Parameter 1 $04 Indicate Remote Station Busy Release (RRBY) Status code $05 Peripheral Input Pin Level (PITL) Status code P P P I I I 2 1 0 $06 P P P T T T 2 1 0 Terminate Frame Transmission (TAIF) Status code Parameter 1 Parameter 2 Parameter 3 SIIN $07 Figure 2-9 Status Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 27 of 168 Terminate U and X Frame Transmission (TAUF) Status code Parameter 1 Parameter 2 Parameter 3 SUXIN $09 Receive Frames (FREC) Status code Parameter 1 Parameter 2 Parameter 3 RBIN $0A Idle Detection (IDET) Status code Parameter 1 Parameter 2 Parameter 3 Parameter 2 Parameter 3 Parameter 2 Parameter 3 Parameter 1 Parameter 2 Parameter 3 Parameter 1 Parameter 2 Parameter 3 Parameter 1 Parameter 2 Parameter 3 $10 System Recovery Request 1 (SRC1) Status code Parameter 1 $11 System Recovery Request 2 (SRC2) Status code Parameter 1 $12 Remote Station System Recovery Request (YRCV) Status code $13 Flag Synchronization (FSYC) Status code $14 Reset Link (LRST) Status code $16 Figure 2-9 Status (cont) 2.0, 05/00, page 28 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Table 2-4 Status Operation Mode Symbol Code Parameters Description Establish link DESI $01 — Responded to request from remote station by trying to establish link — Release link DRLI $02 — Released or prohibited link establishment by remote station — Verify I-frame ACIF $03 ASIIN Verifies that I-frame has been transmitted to remote station — Remote station SRBY busy $04 — Indicates that remote station is busy — Remote station RRBY busy release $05 — Indicates that remote station is released from busy state — Peripheral input PITL pin level $06 PI2-PI0, PT2-PT0 Level of peripheral input changed Terminate frame transmission TAIF $07 SIIN Completed frame transmission Terminate U and X frame transmission TAUF $09 SUXIN UI, XID and TEST frames terminated Powered by ICminer.com Electronic-Library Service CopyRight 2003 Protcol Transparent Command — — Rev. 2.0, 05/00, page 29 of 168 Table 2-4 Status (cont) Operation Mode Command Symbol Parameters Description Receive frames FREC $0A RBIN I, UI, XID ,and TEST frames received correctly Idle detection IDET $10 — Detected idle pattern for more than T3 System recovery request 1 SRC1 $11 — FRMR response received — System recovery request 2 SRC2 $12 — T1 runout occurred N2 times — Remote station YRCV system recovery request $13 — Unrecoverable frame by retransmission received and FRMR response sent — Flag FSYC synchronization $14 — Flag sequence received Reset link $16 — Starts link reset by local station LRST 2.0, 05/00, page 30 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Protcol Transparent Code — Host HD64541 Status request No All zeros in SR Yes Maskable interrupt Set SR ISR1 → 1 Read ISR No ISR1 = 1 Omitted when interrupt is masked and SR is read Interrupt from others Yes Reset ISR1 ISR1 → 0 Read SR All zeros in SR Yes SR-HH = $00 No Omitted when interrupt is performed Status processing Figure 2-10 Status Read Flow Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 31 of 168 2.5 Tables Implemented In External Memory The HD64541 operates on command issued from the external microprocessor. And the HD64541 reports the results of execution or operation state to the external microprocessor if necessary. Figure 2-11 shows nine types of tables provided in external memory and their logical interfaces with the HD64541. The tables are listed in table 2-5. Table 2-5 External Memory Table List Abbrev. Name Size Contents SYSPT System parameter table 32 Overall operating parameters for the HD64541 (For example: protocol mode, N1, N2, K, T1, T2,T3) REJIT Reject frame information table 16 Rejected frame buffer descriptor SIIT Sending I-frame information table 2 + (16 × NSI) (see note) Transmit I-frame buffer descriptors SUXIT Sending U, X frame information table 2 + (8 × NSUI) (see note) Transmit UI, XID, and TEST frame buffer descriptors SDB Transmit data buffer — I-field to be transmitted RBIT Receive buffer information table 16 × NRBI (see note) Receive I-, UI, XID, and TEST frame buffer descriptors RDB Receive data buffer — I-field received SYSDT System parameter dump table 32 Logout area for current system parameters. Layout is same as SYSPT. Written by the HD64541 on command from the external microprocessor. LOGT Statistical information logging table 20 Logout area for statistical information. Written by the HD64541 on command from the external microprocessor. Note: NSI, NSUI, and NRBI are specified within SYSPT (see 2.5.1, System Parameter Table) 2.0, 05/00, page 32 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library HD64541 Command, Status System Memory Space SYSPT (System parameter table) Reset command RSET (SYSPT starting addr) Dump system parameter table command Internal registers SYSDT (System parameter dump table) LOGT (Statistical information logging table) DSPT Dump statistical information command DERC I-frame transmission command DDR1 (FN) DDR2 (FN) SIIT SDB (Sending I-frame (Send data buffer) information table) Addr of bytes for SDB Next SDB info addr SDB ESII (Extended sending I-frame information) REJIT (Reject frame information table) No. of bytes for SDB addr Next SDB info addr ESII FRMR I field U, X frame transmission command SUXIT (Send U, X frame information table) MUDR Command register (CR) Status register (SR) Command status register (CMSR) Interrupt source register (ISR) Interrupt mask register (IMR) Write command Read status SDB Addr of bytes for SDB RBIT (Receive buffer information table) RDB (Receive data buffer) Read command status RDB addr buffer size Read interrupt source Reset interrupt source Set interrupt mask Read interrupt mask Figure 2-11 External Memory Tables Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 33 of 168 2.5.1 System Parameter Table (SYSPT) The SYSPT table passes the values of various parameters that determine operating conditions. Figure 2-12 shows the structure of the SYSPT. Table 2-6 lists the information assigned to each byte of the SYSPT. Byte Bit 7 0 7 PMODE 0 1 7 OMODE 0 2 7 VADD 0 Bit 6 Bit 5 Bit 4 Bit 3 3 3 Bit 2 TDIV Bit 1 Bit 0 0 4 7 LOCA 0 5 7 REMA 0 N1B 8 6 13 7 7 N1B 0 8 7 N2 0 K 0 9 6 10 7 T1 0 11 7 T2 0 12 7 T3 0 13 7 NRBI 0 14 7 NSUI 0 15 7 NSI 0 17 23 REJITA 16 18 15 REJITA 8 19 7 REJITA 0 16 (continued) Figure 2-12 System Parameter Table 2.0, 05/00, page 34 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 20 21 23 SUXITA 16 22 15 SUXITA 8 23 7 SUXITA 0 25 23 SIITA 16 26 15 SIITA 8 27 7 SIITA 0 29 23 RBITA 16 30 15 RBITA 8 31 7 RBITA 0 24 28 Figure 2-12 System Parameter Table (cont) Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 35 of 168 Table 2-6 System Parameter Table Assignments Operation Mode Protocol Mode U, X not Allowed Name Byte Bit Description PMODE 0 7 0: Protocol, 1: Transparent 6 0: modulo 8 5 Reserved (should be set to 0) 4 Delay function for response transmit with T2 U, X Allowed (0) Transparent (1) — 1: modulo 128 — — — 0: Transmits response immediately 1: Waits for a duration equal to T2 3 Link disconnection supervisory function with T3 0: Reports link disconnection immediately 1: Waits for a duration equal to T3 2 Specifies whether to accept U, X frame (UI, TEST, XID) or not. 0: Receive or transmit inhibit 1: Accept 1 Timestep for T3 0: 0.1 sec step, 0.1 to 25.5 sec 1: 1 sec step, 1 to 255 sec 0 Interframe timefill 0: Flag 1: Mark OMODE 1 5 to 7 Reserved (should be set to 0) 4 Minimum frame interval when transmitting multiple-frame by one command 0: approx. 80 µs 1: approx. 300 µs (system clock 6 MHz) 2.0, 05/00, page 36 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library (0) (1) — Table 2-6 System Parameter Table Assignment (cont) Operation Mode Protocol Mode Name Byte Bit OMODE 1 1 to 3 Protocol mode 0 U, X not Allowed Description bit3 0 0 0 bit2 0 0 1 bit1 0 X.25 layer 2 1 X.75 layer 2 0 T.90 layer 2 U, X Allowed Transparent — 0: Reserved 1: Normal mode (should be set to 1) VADD 2 0 to 7 Vector address issued when interrupt acknowledge is received after an interrupt request TDIV 3 0 to 3 Specify the basic timer frequency with the internal operating clock frequency by MHz unit. 2 to 6 is valid. Note: For the double frequency mode, specify one half of the frequency of the CLK input. (only for the HD64541S) LOCA 4 0 to 7 Local station address — REMA 5 0 to 7 Remote station address — N1B 6 0 to 5 Number of bytes in the largest 7 0 to 7 I-frame information field. (Do not set to 0) — (See note) N2 8 0 to 7 Maximum allowable number of transmit retries (Do not set to 0) — K 9 0 to 6 Maximum number of outstanding I frames (Shoud be set in 0< K< modulo value) — T1 10 0 to 7 Limit value for receive confirmation timer set in units of 0.1 seconds (Do not set to 0) — T2 11 0 to 7 Limit value for the delayed acknowledgement timer set in units of 0.1 seconds (Do not set to 0) — Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 37 of 168 Table 2-6 System Parameter Table Assignment (cont) Operation Mode Protocol Mode Name Byte Bit Description T3 12 0 to 7 Limit value for the link disconnection supervisory timer set in units of 0.1 or 1 seconds (Do not set to 0) U, X not Allowed U, X Allowed Transparent It is selected by PMODE bit1 NRBI 13 0 to 7 Number of RBIs (Should be set to NRBI ≥ 3) NSUI 14 0 to 7 Specifies the number of SUXI (Should be set to NSUI ≥ 1) NSI 15 0 to 7 Number of Sll (Should be set to NSI ≥ 1) Reserved 16 REJITA 17 0 to 7 Reserved (should be set to 0) 0-7 19 0-7 0 to 7 Reserved (should be set to 0) SUXITA 21 0 to 7 Specifies the address of SUXIT 22 0 to 7 23 0 to 7 Reserved 24 0 to 7 Reserved (should be set to 0) SIITA 0 to 7 Address of SIIT 26 0-7 27 0-7 Reserved 28 0 to 7 Reserved (set to 0) RBITA 0 to 7 Address of RBIT 29 — — — 0 to 7 Address of REJIT 18 Reserved 20 25 — 30 0-7 31 0-7 — — — — — — — — — 14 Note: In transparent mode, any frame received with a frame length exceeding 2 bytes (excluding frame start/end frag and FCS) will be discarded. 2.0, 05/00, page 38 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 2.5.2 Reject Frame Information Table (REJIT) The REJIT table stores the FRMR frame information field. The HD64541 performs both read and write access to this table. REJIT can be read from but cannot be written to by the external microprocessor. The external microprocessor only needs to reserve an area in memory by specifying the address of this table in REJITA of the SYSPT; it does not have to specify table values. This table is not used in transparent mode. Byte Bit 7 0 7 1 2 Bit 6 Bit 5 Bit 3 Bit 2 Bit 1 TCF TVR 0 Bit 4 0 0 TCR 0 0 Bit 0 TVS TZ TY 0 TX TW 3 Transmit FRMR I-field 4 5 6 7 8 7 9 10 RCF RVR 0 0 0 RCR 0 0 RVS RZ RY 0 RX 11 RW Receive FRMR I-field 12 13 14 15 (modulo 8) Figure 2-13 Reject Frame Information Table Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 39 of 168 Byte Bit 7 0 7 TCF 0 1 7 TCF 0 Transmit 2 7 TVS 1 0 FRMR 3 7 TVR 1 TCR I-field 4 0 TX TW Bit 6 0 Bit 5 0 Bit 4 0 Bit 3 TZ Bit 2 TY Bit 1 Bit 0 5 6 7 8 7 RCF 0 9 7 RCF 0 Receive 10 7 RVS 1 0 FRMR 11 7 RVR 1 RCR I-field 12 0 RX RW 0 0 0 RZ RY 13 14 15 (modulo 128) Figure 2-13 Reject Frame Information Table (cont) 2.0, 05/00, page 40 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Table 2-7 Reject Frame Information Table Assignments Modulo 8 Name Byte Bit TCF 0 0 to 7 Modulo 128 Byte Bit Description Control field of rejected frame. 0 0 to 7 1 0 to 7 TVS 1 1 to 3 2 1 to 7 Send state variable of local station during FRMR transmission. TCR 1 4 3 0 If the rejected frame is response,TCR is set to 1; if the rejected frame is command, to 0. TVR 1 5 to 7 3 1 to 7 Receive state variable of local station during FRMR transmission. TW 2 0 4 0 If the control field of received frame is undefined, TW is set to 1. TX 2 1 4 1 TX set to 1 indicates that received frame contains an information field which is not permitted in this frame. TX is also set to 1 if the length of received S or U frame is invalid. TW must be set to 1 together with this bit. TY 2 2 4 2 If the length of the information field in the received I-frame is longer than N1, TY is set to 1. TY and TW are not set to 1 concurrently. TZ 2 3 4 3 TZ is set to 1 if received N(R) value is invalid. TZ and TW are not set to 1 concurrently. — 3 to 7 5 to 7 Reserved RCF 8 0 to 7 8 9 0 to 7 RVS 9 1 to 3 10 1 to 7 Send state variable of remote station when transmitting FRMR. RCR 9 4 11 0 If the rejected frame is response, RCR is set to 1; if the rejected frame is command, to 0. RVR 9 5 to 7 11 1 to 7 Receive state variable of remote station when transmitting FRMR. RW 10 0 12 0 RW is set to 1 if the control field of a frame received at the remote station is undefined. RX 10 1 12 1 RX set to 1 indicates that the frame received at the remote station contains an information field which is not permitted in this frame. RX is also set to 1 if the length of S or U frame received at the remote station is invalid. If RX is set to 1, RW is also set to 1. 0 to 7 Powered by ICminer.com Electronic-Library Service CopyRight 2003 Control field of rejected frame. Rev. 2.0, 05/00, page 41 of 168 Table 2-7 Reject Frame Information Table Assignments (cont) Modulo 8 Modulo 128 Name Byte Bit Byte Bit Description RY 10 2 12 2 RY is set to 1 if the length of the information field of an I frame received at the remote station is longer than N1. RY and RW are not set to 1 concurrently. RZ 10 3 12 3 RZ is set to 1 if N(R) received at the remote station is invalid. RZ and RW are not set to 1 concurrently. 11 to 15 13 to 15 Reserved 2.0, 05/00, page 42 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 2.5.3 Sending I-Frame Information Table (SIIT) The SIIT (figure 2-14) is a specifiable length table that holds data buffer descriptors for I-frames to be transmitted. It contains one entry per I-frame (each entry is known as an SII). The starting address of SIIT is kept in the SYSPT. The size of the SIIT (NSI) is expressed in terms of the number of SIIs it contains. Table 2-8 describes the SIIT contents. The SIIT is also used in transparent made. Table 2-8 Sending I-Frame Information Table Assignments Name Byte Bit Description NSIIN 0 0 to 7 Index to the next active buffer descriptor (SII), which specifies the next I-field to be transmitted when the transmit I-frame command is received from the external microprocessor SBC 2 0 to 4 3 0 to 7 Length in bytes of buffer data to be transmitted. When buffers are chained together using the CD indicator and ESII descriptors, SBC specifies only the length of the current buffer. An SBC field in the ESII specifies the length of the buffer associated with that ESII. (see note 1) SAD 5 to 7 0 to 7 Starting address of the transmission buffer CD 8 0 Indicates chained data (frame overlaps with the next buffer) 0: Data not chained 1: Data chained CTAD 11 to 13 0 to 7 Indicates starting address of the ESII table, which stores information for the next chained data buffer (ESII has the same format as the SII (see note 2)) Notes: 1. A value of 0 in the SBC field of the SII causes the I-frame to be transmitted without an Ifield. A value of 0 in the SBC of an ESII causes the I-frame to be aborted when that ESII is fetched to continue the chained buffer I-frame transmission. 2. The ESII has the same format as the SII. The ESII need not be allocated storage in memory contiguous with the SII. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 43 of 168 Byte Bit 7 0 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 NSIIN Bit 0 0 1 2 3 12 SBC Common byte 8 7 SBC 0 5 23 SAD 16 6 15 SAD 8 7 7 SAD 0 4 8 CD 9 SII SIIN = 0 10 11 23 CTAD 16 12 15 CTAD 8 13 7 CTAD 0 14 15 16 17 18 12 SBC 8 SII SIIN = 1 The sending I-frame information table consists of common bytes and an NSI number of SIIs. The end of the table depends on the value of NSI in SYSPT. Figure 2-14 Sending I-Frame Information Table 2.0, 05/00, page 44 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 2.5.4 Sending U, X Frame Information Table (SUXIT) The SUXIT (figure 2-15) is a specifiable length table that holds output data buffer descriptors for UI, XID and/or TEST frames to be transmitted. It contains one entry per frame (each entry is known as an SUXI). There is only one SUXIT for the HD64541. The starting address of the SUXIT is kept in the SYSPT, as is its size, expressed as the number of SUXIs in the table. Table 2-9 describes the SUXIT contents. Note that the HD64541 does not allow for data chaining on transmit UI, XID and TEST frames. If PMODE bit 2 of the SYSPT is set to 0, the SUXIT cannot be used. Moreover, in transparent mode, the SUXIT is not used. Table 2-9 Name Sending U, X Frame Information Table Assignments Byte Bit Description NSUXIN 0 0 to 7 Index to the next active buffer descriptor (SUXI), which specifies the next I-field to be transmitted when the MUDR command to transmit UI, TEST or XID is received from the external microprocessor TYP 5 to 7 Bits: 765 2 Type of frame 010: TEST command 011: TEST response 100: UI command 101: UI response 110: XID command 111: XID response G 2 0 Setting G to 1 specifies global address PF 3 7 Value of the P/F bit for in the control field of the frame to be transmitted (See section 3.1.3) SBC 4 0 to 4 Length in bytes of the I-field of the frame to be transmitted 5 0 to 7 7 0 to 7 8 0 to 7 9 0 to 7 SAD Starting address of SDB Note: If SBC is set to 0, the UI, XID, or TEST frame is sent without an I field. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 45 of 168 Byte Bit 7 0 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 NSUXIN Bit 1 Bit 0 0 1 2 3 G TYP PF 4 5 Common byte 12 7 SBC SBC 8 0 SUXI SUXIN = 0 6 7 23 SAD 16 8 15 SAD 8 9 7 SAD 0 SUXI SUXIN = 1 The sending U, X frame information table consists of an NSUI number of SUXIs. The starting address of the table is SUXITA specified in the system parameter table (SYSPT); the end address of the table depends on the value of NSUI in SYSPT. Figure 2-15 Sending U, X Frame Information Table 2.0, 05/00, page 46 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 2.5.5 Transmit Data Buffer (SDB) The SDB (figure 2-16) holds all or part of an I-field for transmission in an I-, UI, XID, or TEST frame. The SDB address and byte count are stored in the SII or ESII buffer descriptors. Long Ifields may be constructed from multiple SDBs by means of the SII/ESII chaining mechanism. The SDB data are transmitted in bytes 0,1,2,etc. of SDB from bit 0 to 7 for each byte. The SDB is also used in transparent mode. Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 1 Transmission data Indicates bit transmission sequence Figure 2-16 Transmit Data Buffer 2.5.6 Receive Buffer Information Table (RBIT) The RBIT (figure 2-17) is a specifiable length table that holds input data buffer descriptors for Ifields that may be received from the remote station. The I-fields may be carried in I-, UI, XID, or TEST frames. It is up to the external microprocessor’s software to sort out the received I-fields. The RBIT contains one entry per input buffer (each entry is known as an RBI). There is only one RBIT for the HD64541. The starting address of the RBIT is kept in the SYSPT, as is the size of the RBIT, expressed in number of descriptor entries. Table 2-10 describes the RBIT contents. When a frame is received whose I-field does not fit into one buffer, the HD64541 takes the next RBI in the table and continues the receive operation, setting the chained data indicator in the previous RBI. For I-fields chained together in this manner, only the starting RBI contains frame header information. Rev. 2.0, 05/00, page 47 of 168 Table 2-10 Receive Buffer Information Table Assignments Operation Mode Protocol Mode U, X not Allowed Name Byte Bit Description PF 0 6 PF bit value of received frame, invalid in transparent mode or if TYP is 000. G 0 0 Set to 1 when a frame having a global address is received; invalid in transparent mode or if TYP is 000. RBC 2 0 to 5 Actual byte count of the received I0 to 7 field–if the I-field spilled over into chained buffers, the RBC field is valid only in the first RBI and is the total byte count across all of the buffers that were chained together to hold the complete I-field. Received byte count excluding flags and the FCS in transparent mode. 3 BS 4 7 Buffer status–Set high by the external microprocessor when the buffers are ready to receive data and set low by HD64541 after transmission and setting required information in RBI. CD 4 6 Chained data–Indicates when frames longer than the receive buffer are received (frame will overlap into next buffer). 0: Not chained TYP RBS 4 6 7 RAD 0 to 2 Bits: 210 U, X Allowed Transparent — — — 1: Chained Type of frame received 000: I command 010: TEST command 011: TEST response 100: UI command 101: UI response 110: XID command 111: XID response 0 to 4 Length in bytes of the receive data 0 to 7 buffer (RDB). 9 to 11 0 to 7 Starting address of RDB. 0 to 7 0 to 7 2.0, 05/00, page 48 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library — Byte Bit 7 Bit 6 0 0 PF 2 0 0 3 7 4 BS CD 6 0 0 7 7 RBS 0 9 23 RAD 16 10 15 RAD 8 11 7 RAD 0 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 G 1 13 8 RBC RBC 0 TYP 5 0 12 RBS 8 8 RBI RBIN = 0 12 13 14 15 16 RBI RBIN = 1 1. The table consists of RBI sections. The number of RBI sections is NRBI. 2. The starting address of the table is RBITA specified in the system parameter table. 3. The end address of the table depends on the value of NRBI in the system parameter table. 4. Bytes 4 and 5 of an RBI are read and written by both the external microprocessor and HD64541. 5. Bytes 0 to 3 of an RBI are written by the HD64541 and read by the external microprocessor. 6. Bytes 6 to 11 of an RBI are written by the external microprocessor and read by the HD64541. 7. If an I-frame (UI, XID or TEST frame) is stored extending over two or more buffers, TYP, RBC, PF, and G of the frame will appear only in the RBI corresponding to the first buffer. 8. PF, G and TYP are invalid in transparent mode. 9. Global address is valid only for UI, XID and TEST frames. Specification of a global address for frames other than UI, XID and TEST will cause an address field error. 10. If a frame with a global address is received, TYP will show only commands; however, if the frame is received in loopback mode, it will show only responses. Notes: 1. With chained data, only the values set in the first RBI are valid. 2. When the HD64541 is placed in on-line mode from off-line mode, the LSI starts reading the buffer from the first RBI; consequently, RBIT must be initialized before entering online mode. Figure 2-17 Receive Buffer Information Table Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 49 of 168 2.5.7 Receive Data Buffer (RDB) The receive data buffer passes I-field information contained in received frames (I-, UI, XID or TEST frame) to the external microprocessor. The HD64541 accesses the RDB to perform write operations. Figure 2-18 shows the buffer structure . The received frames are stored in bytes 0, 1, 2, etc. of RDB from bit 0 to bit 7 for each byte. The RDB is also used in transparent mode. Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 1 Received data Indicates received bit sequence Figure 2-18 Receive Data Buffer 2.5.8 System Parameter Dump Table (SYSDT) The SYSDT is the logout area used by the HD64541 to dump a copy of its currently active operating parameters on a DSPT command from the external microprocessor. SYSDT’s layout is identical to SYSPT’s. A 0 is written in each column corresponding to a slash in SYSPT. The SYSDT can also be used in transparent mode. 2.0, 05/00, page 50 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 2.5.9 Statistical Information Logging Table (LOGT) The LOGT (figure 2-19) is the logout area in external memory into which the HD64541 dumps certain statistical information on command (DERC) from the microprocessor. LOGT consists of one-byte binary counters that freeze when the count reaches 255. DERC resets all of the counters in LOGT. Figure 2-19 and table 2-11 show table structure and description of each counter, respectively. Byte No. FCS error LOGT +0 1 Short frame 2 Residual bit frame 3 Abort frame 4 Address field error 5 Overrun error 6 Idle 7 Underrun error 8 Procedure error 9 T1 timer runout 10 Remote station busy 11 Local station busy 12 Retransmission procedure start 13 REJ transmission 14 REJ reception 15 FRMR transmission 16 FRMR reception 17 00 18 00 19 00 Figure 2-19 Statistical Information Logging Table Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 51 of 168 Table 2-11 Statistical Information Logging Table Assignments Byte No. Counter Name Receive Item Counted Counter Length (bytes) 0 FCS error FCS error frame 1 1 Short frame In modulo 8, short frame is a frame in 1 which the length between flags is less than 4 octets; in modulo 128, the length is less than 5 octets in I, S frames or 4 octets in U frame. 2 Residual bit frame Frames not constructed in units of octets 1 3 Abort frame Frames that contains a bit string consisting of more than seven consecutive 1s 1 4 Address field error Frames having an undefined address field including G frame except optional frames 1 5 Overrun error Overrun error in receive buffer 1 6 Idle Line state transition from flag to idle (not the number of times idle detection status is reported; idle detection status is reported only when T3 timer runout occurs) 1 7 Underrun error Underrun errors in the transmission buffer 1 8 Procedure error Number of unexpected frames received except undefined C field frame 1 — 9 T1 timer runout T1 timer runout 1 — 10 Remote station busy Remote station busy (not the number of times RNR is received) 1 — 11 Local station busy Local station busy on established link (Include is both the number of Set Local Station To Busy State commands from the external microprocessor and the number of internal busy occurrences) 1 — 12 Retransmission procedure start Retransmission start due to check pointing or reception of REJ frame (not number of retransmission I frames) 1 — 13 REJ transmission REJ command / response transmission 1 — Note: : Counted —: Not counted 2.0, 05/00, page 52 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library TransProtocol parent — Table 2-11 Statistical Information Logging Table Assignments (cont) Byte No. Counter Name Receive Item Counted Counter Length (bytes) 14 REJ reception REJ command/response reception 1 — 15 FRMR transmission FRMR response transmission 1 — 16 FRMR reception FRMR response reception 1 — 17 (reserved) 1 — — 18 (reserved) 1 — — 19 (reserved) 1 — — Note: : Counted —: Not counted TransProtocol parent Notes: 1. Counters 0 to 5 have higher priority than 8 to 16. 2. If a frame with two or more errors in counters 0 to 5 is received, only one item is counted per frame according to the following priority order: High 5 Overrun ↑ 3 Abort frame 1 Short frame 0 FCS error ↓ 2 Residual bit Low 4 Address format error 3. Counter 8 (procedure error) counts received frames with good address field, but which are not expected on protocol procedure. 4. A counter that counts nothing reads 0. 5. The following shows the idle count conditions by counter 6. IDET status reporting condition • Receive continuous 1s for a period of at least 15 bit times when line rate is up to 1.5 Mbps. • Receive continuous 1s for a period of at least 18 bit times when line rate is more than 1.5 Mbps. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 53 of 168 2.0, 05/00, page 54 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Section 3 LAPB Data Link Control Protocol Since the HD64541 is designed under the guidelines set forth in CCITT recommendation T.90 layer 2 ('88), X.75 layer 2 ('88), X.25 layer 2('88), you should become familiar with the recommendation before reading this chapter. The HD64541 does not support the multilink operation, only the single link operation of the recommendation. T.90 mode supports information transfer phase in exchange mode of ISDN. (DTE-DTE) 3.1 Frame Structure Figure 3-1 and 3-2 show the structure of frames transmitted and received by the HD64541. Transmit bit sequence 12345678 12345678 12345678 16-1 12345678 Flag Address Control FCS Flag F 01111110 A 8 bits C 8 bits FCS 16 bits F 01111110 FCS frame check sequence Transmit bit sequence 12345678 12345678 12345678 Flag Address Control F 01111110 A 8 bits C 8 bits 16-1 12345678 Information FCS Flag I N bits FCS 16 bits F 01111110 FCS frame check sequence Figure 3-1 Frame Format in Modulo 8 Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 55 of 168 Transmit bit sequence 12345678 12345678 1-* 16-1 12345678 Flag Address Control FCS Flag F 01111110 A 8 bits C * bits FCS 16 bits F 01111110 FCS frame check sequence Transmit bit sequence 12345678 12345678 1-* Flag Address Control F 01111110 A 8 bits C * bits 16-1 12345678 Information FCS Flag I N bits FCS 16 bits F 01111110 FCS frame check sequence *: For frame formats containing a sequence number, there are 16 bits. For frame formats containing no sequence number, there are 8 bits. Figure 3-2 Frame Format in Modulo 128 3.1.1 Flag All frames are delimited by a start and end FLAG sequence, which consists of one or more repetitions of the bit pattern 01111110. For frames received by the HD64541, the closing FLAG of one frame may also serve as the opening FLAG of the next successive frame. On transmit, however, the HD64541 always sends at least two flags between successive frames. 7 6 5 4 3 2 1 0 0 1 1 1 1 1 1 0 Figure 3-3 Flag Format 2.0, 05/00, page 56 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 3.1.2 Address Field Figure 3-4 shows the address field of a frame. The address of the receiving station is written into the command. The address of the sending station is written into the response. The address shown in figure 3-4 is set in SYSPT’s LOCA and REMA fields. Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 A 0 0 0 0 0 0 1 1 B 0 0 0 0 0 0 0 1 Figure 3-4 Address Field Format 3.1.3 Control Field Table 3-1 and table 3-2 show the bit assignments for the control field of frames transmitted and received by the HD64541. The control field identifies the frame type. Depending on the frame type, it may also carry a receive sequence number N(R), a transmit sequence number N(S), or both. All frames carry a poll/final (P/F) bit. The N(S) sequence number tags I-frames transmitted by the HD64541. Each successive I-frame gets an N(S) value one higher than the previous, modulo 8 or 128. The N(R) sequence number is the receiver’s acknowledgement that transmitted I-frames have been received without error and in proper sequence. Command frames carry a POLL bit, which may be either 0 or 1, in the POLL/FINAL bit position. Response frames carry a FINAL bit. POLL/FINAL bits are generally used in conjunction with timers to perform checkpointing procedures for transmission error recovery. 3.1.4 Information Field The contents of the information field consist of an integer number of octets. The HD64541 imposes no limit on the size of the information field that it can transmit. It is up to the user to assure that the maximum I-field transmitted is compatible with the receiver’s capability. The HD64541 can receive I-fields up to 16,383 bytes long, representing the maximum value that can be loaded into the SYSPT’s 14-bit wide N1B parameter. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 57 of 168 3.1.5 FCS (Frame Check Sequence) The 16-bit FCS sequence is the complement of the sum (modulo 2) of 1 and 2 described below: K 15 14 1. The remainder of X (X + X + .... + X + 1) divided (modulo 2) by the generator polynomial 16 12 5 X + X + X + 1, where K is the number of bits between the last bit of the opening flag and the first bit of FCS. 16 12 5 2. The remainder of the division (modulo 2) by the generator polynomial X + X + X + 1, of 16 the product of X by the content of the frame between the last bit of the opening flag and the first bit of FCS. Table 3-1 Control Field Bit Configuration in Modulo 8 Control Selection Format Frame Name Information format Information (I-frame) Supervisory format (S frame) Unnumbered format (U frame) Abbrev. 7 I 6 5 4 3 2 1 N(S) 0 N(R) P 0 Receive Ready RR N(R) P/F 0 0 0 1 Receive Not Ready RNR N(R) P/F 0 1 0 1 Reject REJ N(R) P/F 1 0 0 1 Set SABM Asynchronous Balanced Mode 0 0 1 P 1 1 1 1 Disconnect Mode DM 0 0 0 F 1 1 1 1 Frame Reject FRMR 1 0 0 F 0 1 1 1 Disconnect DISC 0 1 0 P 0 0 1 1 Unnumbered Acknowledge UA 0 1 1 F 0 0 1 1 Unnumbered Information UI 0 0 0 P/F 0 0 1 1 Exchange Identification XID 1 0 1 P/F 1 1 1 1 Test TEST 1 1 1 P/F 0 0 1 1 2.0, 05/00, page 58 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Table 3-2 Control Field Bit Configuration in Modulo 128 Control Selection Format Frame Name Information format Information (I-frame) Supervisory format (S frame) Abbrev. 7 6 5 I Receive Ready RR 0 0 0 4 3 2 1 N(S) 0 N(R) P 0 0 0 0 N(R) Receive Not Ready RNR Reject REJ 0 0 0 0 0 0 0 0 1 0 1 P/F 1 0 0 N(R) Unnumbered format (U frame) 1 P/F N(R) 0 0 1 P/F Set SABM Asynchronous Balanced Mode 0 1 1 P 1 1 1 1 Disconnect Mode DM 0 0 0 F 1 1 1 1 Frame Reject FRMR 1 0 0 F 0 1 1 1 Disconnect DISC 0 1 0 P 0 0 1 1 Unnumbered Acknowledge UA 0 1 1 F 0 0 1 1 Unnumbered Information UI 0 0 0 P/F 0 0 1 1 Exchange Identification XID 1 0 1 P/F 1 1 1 1 Test TEST 1 1 1 P/F 0 0 1 1 Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 59 of 168 3.1.6 Interframe Time Fill Interframe time fill is accomplished using sequential transmission of flags according to CCITT recommendation. HD64541, however, provides a selection between flags and marks for interframe time fill. The optional selection (marks) is useful during system development debugging. Interframe time fill is selected using PMODE 0 bit (0 = flag; 1 = mark) in the SYSPT. Figure 3-5 shows an example of link setting by remote station and I-frame receipt when mark is selected for interframe time fill. Host MPU , , , Remote station Local station HD64541 Reset command (RSET) Set operating mode command (OMDS) Establish link command (DESR) Command normal end (CMSR2–CMSR0 = 000) Command normal end (CMSR2–CMSR0 = 000) Command normal end (CMSR2–CMSR0 = 000) SABM, P UA, F Flag synchronization status (FSYC) Idle detect (IDET) Establish link status (DESI) Flag synchronization status (FSYC) I, 0, 0, P RR, 1, F Idle detect (IDET) Receive frames status (FREC) Figure 3-5 Example of Sequence for Interframe Time Fill as Mark 2.0, 05/00, page 60 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 3.2 Frame Type The types of frames transmitted and received by the HD64541 are classified into command and response as shown in table 3-3. Table 3-3 Command and Response Command Response I RR RR RNR RNR REJ REJ SABM/SABME DM FRMR DISC UA UI UI XID XID TEST TEST Note: A blank entry indicates an undefined frame. 3.2.1 I Command (Information) The information (I) command carries higher layer data in its I-field across a logical link. I commands are protected by sequence numbers and are subject to retransmission error recovery and flow control procedures. I-frame transmission is not allowed until a successful SABM/UA (or SABME/UA) exchange has been completed. The HD64541 transmits I-frames on command (DDR1 or DDR2) from the external microprocessor. 3.2.2 SABM Command (Set Asynchronous Balanced Mode) and SABME Command (Set Asynchronous Balanced Mode Extended) The SABM(in modulo 8)/SABME(in modulo 128) command establishes a logical link for the sequenced exchange of I-frames. SABM/SABME carries no I-field and requires a UA response to complete the handshake. The HD64541 transmits SABM/SABME on command (DESR) from the external microprocessor and waits for a UA response. It automatically transmits a responding UA on reception of SABM/SABME. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 61 of 168 3.2.3 DISC Command (Disconnect) The DISC command takes down a logical link previously established by a SABM/UA (SABME/UA) exchange. DISC carries no I-field and requires a UA response to complete the handshake. Following reception or transmission of DISC, further I-frame transmission on the logical link is prohibited. The HD64541 transmits DISC on command (DRLR) from the external microprocessor and waits for a UA response, but will also accept a DM response. The HD64541 automatically sends a UA response on reception of DISC. 3.2.4 RR Command/Response (Receive Ready) The RR supervisory frame is used for the following purposes: 1. To indicate that the station sending the RR is ready to receive I-frames. 2. To clear a busy condition set by a previously transmitted RNR. 3. To carry the N(R) acknowledgement sequence number. N(R) = z indicates that all I-frames with N(S) less than z (modulo 8 or 128) have been correctly received. 4. To carry P/F bit = 1 for checkpointing. RR frames are generated in the normal course of protocol operation by the HD64541, but are also sent on command (RSBY) from the external microprocessor. RSBY release the local station from a busy condition established earlier by SSBY. 3.2.5 REJ Command/Response (Reject) The REJ supervisory frame explicitly requests retransmission of I-frames starting with the one that carries an N(S) value equal to the N(R) in the REJ. This implicitly acknowledges all I-frames with N(S) less than N(R) (modulo 8 or 128). REJ is transmitted whenever an I-frame is received out of sequence, indicating that the missing frame(s) were likely to have been corrupted by transmission errors and discarded immediately after failing an FCS check. 3.2.6 RNR Command/Response (Receive Not Ready) The RNR supervisory frame indicates a local busy condition. The transmitter of an RNR is temporarily unable to accept additional I-frames and requests that the receiver of RNR suspend its transmission until further notified by RR. The N(R) sequence number carried in the RNR acknowledges I-frames as normally expected . RNR frames are generated in the normal course of protocol operation by the HD64541 but are also sent on command (SSBY) from the external microprocessor. SSBY places the local station into a busy condition. 2.0, 05/00, page 62 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 3.2.7 UA Response (Unnumbered Acknowledgement) The UA frame is the expected response to the SABM/SABME command and the DISC command. For logical link bringup, the SABM/SABME is repeated at T1 timeout intervals until UA is received. For logical link takedown, after a certain number of DISC retransmissions without receiving UA, the logical link is simply declared disconnected. 3.2.8 DM Response (Disconnected Mode) The DM response reports that the logical link is in disconnected mode and that the SABM/UA (SABME/UA) exchange is required before I-frames may be exchanged. If DM is received in response to SABM/SABME, it indicates that the station receiving SABM/SABME is currently unable to comply with the link establishment request. An unsolicited DM with F = 0 is considered an invitation to transmit SABM/SABME to set up the logical link. 3.2.9 FRMR Response (Frame Reject) Receipt of FRMR indicates that the station transmitting FRMR has detected an error that is not recoverable by retransmission, such as the following: 1. A frame was received that contained an undefined or not implemented control field value. (which are not indicated in table 3-1 or table 3-2) 2. A supervisory or unnumbered frame with incorrect length was received. 3. A frame was received that carried an invalid N(R) value (one that acknowledges more I-frames than are outstanding on the logical link). N(R) in the range [V(A) ≤ N(R) ≤ V(S)] is valid. 4. An I-frame was received that carries an I-field exceeding a preestablished maximum. 5. An unexpected supervisory frame with F = 1 was received. 6. An unexpected UA, or DM response was received. 7. A frame with an invalid N(S) was received. An information field holds the reason for an FRMR response. Figure 3-5 shows the format of the information field. After FRMR is transmitted, the HD64541 goes into error recovery state. It returns to the data link setting state, when in X.25 or X.75 mode, after reception of SABM/SABME from the remote state or after transmitting SABM/SABME after T1 timer runout occurs N2 times. In the X.75 mode, FRMR response frame is transmitted to notify other error states as follows. In this case, W in the I-field is set to 1. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 63 of 168 Modulo 128 Modulo 8 7 6 5 4 3 2 1 0 7 Control field of rejected frame V (R) 0 0 C/R 0 0 V (S) Z Y 6 5 4 3 2 1 0 Control field of rejected frame 0 1 0 X W 0 0 Send state variable V (S) 0 2 Receive state variable V (R) CR 3 W 4 0 0 Z Y X Rejected frame was a response. Rejected frame was a command. Received control field command/response was undefined or not implemented. Received command/response contains an information field which is not permitted in this frame. Bit W must be 1 when bit X is 1. 1: Information field received exceeds the maximum established information field length. 1: Received control field contained an invalid N(R). C/R: 1: 0: W: 1: X: 1: Y: Z: Figure 3-6 FRMR Information Field 3.2.10 UI Command/Response (Unnumbered Information) The UI frame carries higher layer data in its I-field across a logical link as does the I command described earlier. UI, however, is not subject to sequence numbering, flow control, or transmission error detection or recovery. UI frames may be exchanged over a logical link without a successful SABM/UA(SABME/UA) handshake. Transmission and reception of the UI frame does not affect operation mode or state variables. The HD64541 transmits UI on command (MUDR) from the external microprocessor. Though CCITT recommendation T.90, X.75, and X.25 do not include UI frames, the HD64541 does provide them. The use of this frame is specified by bit 2 of PMODE in SYSPT. If UI frame use is not specified, the received UI frame will be treated as an undefined frame. 3.2.11 TEST Command/Response The TEST frame perform is basic testing data link of: TEST frames may be exchanged over a logical link without a successful SABM/UA SABME/UA handshake. Transmission and reception of the TEST frame does not affect operation mode or state variables. The HD64541 transmits TEST on command MUDR from th external microprocessor. Though CCITT recommendation T.90, X75, and X.25 do not include TEST frames, the HD64541 does provides them. The use of this frame is specified by bit 2 of PMODE in SYSPT. If TEST frame use is not specified, the received TEST frame will be treated as an undefined frame. 2.0, 05/00, page 64 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 3.2.12 XID Command/Response (Exchange Identification) XID frames are used to exchange system parameter values. XID frames may be exchanged over a logical link without a successful SABM/UA SABME/UA handshake. Sending or receiving an XID frame has no effect on the operational mode or state variables. The HD64541 transmits XID on command MUDR from the external microprocessor. Though CCITT recommendation T.90, X75, and X.25 do not include XID frames, the HD64541 does provides them. The use of this frame is specified by bit 2 of PMODE in SYSPT. If XID frame use is not specified, the received XID frame will be treated as an undefined frame. 3.3 Frame Transmission 3.3.1 Bit Transmission Order Transmission of the address field, control field, and information field begins with the LSB (bit 0), while transmission of the FCS field begins with the MSB (bit 15). 3.3.2 Invalid Frames The HD64541 discards the following frames as an invalid frame without notifying the sender: 1. A frame that is not properly bounded by a starting flag and an ending flag. 2. In modulo 8, a frame whose length between flags is less than 32 bits. In modulo 128, a frame whose length including a sequence number between flags is less than 40 bits; if it does not have a sequence number, a frame whose length is less than 32 bits. 3. A frame that does not contain an integral number of octets prior to zero-bit insertion or following zero-bit deletion. 4. A frame containing an FCS error 5. A frame having an address other than those shown in figure 3-4. 3.3.3 Abort (Frame Discard) The HD64541 interprets a string of seven or more 1s as an abort and ignores the frame currently being received. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 65 of 168 3.3.4 Transparency Zero-bit insertion and deletion is used to achieve transparency. All data link control bit patterns contain at least six consecutive 1 bits. The zero insertion process inserts a 0 bit into the transmit data stream following five consecutive 1 bits, so that no random data patterns will be mistaken for a data link control bit pattern. The inserted bits are removed at the receiver. Zero insertion and deletion operates between the opening and closing flags of a frame. 3.4 System Parameters and State Variables 3.4.1 System Parameters The external microprocessor can be set the following system parameters: Timer T1: The maximum time the receiver is allowed for sending back a required response. T1 can be set in the system parameter table (SYSPT) in increments of 0.1 second up to a maximum of 25.5 seconds. Timer T2: A timer for delayed acknowledgement. T2 can be set in the system parameter table (SYSPT) in increments of 0.1 second up to a maximum of 25.5 seconds. Timer T3: The maximum time allowed without flags being exchanged. T3 can be set in the system parameter table (SYSPT) in increments of 0.1 seconds up to a maximum of 25.5 seconds or in increments of 1 second up to a maximum of 255 seconds. Maximum Number of Outstanding I-Frames K (window size): The number of I-frames that can be successively sent without acknowledgement from the remote station. The maximum value of K that can be set in the system prameter table (SYSPT) is 7 in modulo 8, and 127 in modulo 128. Maximum Number of Bits (or Octets) in an Information Field N1 (N1B): The maximum number of octets allowed in a received I-field. The maximum value of N1B that can be set in the system parameter table (SYSPT) is 16,383. According to CCITT recommendation, N1 is the length of N1B + address field + control field + FCS field (in bits). Maximum Number of Retransmissions N2: The maximum number of retransmissions of a frame. The maximum value of N2 that can be set in the system parameter table (SYSPT) is 255. 2.0, 05/00, page 66 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 3.4.2 State Variables Internal state variables managed by the HD64541 are described below. In modulo 8 all of them range in value from 0 to 7 and are incremented modulo 8. In modulo 128 all of them range in value from 0 to 127 and are incremented modulo 128. The variables cannot be written by the external microprocessor. Send State Variable V(S): The sequence number of the next I-frame to be transmitted. Initialized to 0 after the SABM/UA(SABME/UA) exchange, V(S) is incremented by one after each I-frame is transmitted. Acknowledge State Variable V(A): The sequence number of the oldest unacknowledged I-frame still outstanding on the logical link. V(A) is updated whenever an N(R) is received from the remote station that acknowledges additional frames. Send Sequence Number N(S): The sequence number of a transmitted I-frame. As each I-frame is prepared for transmission, its N(S) field is set to the current value of V(S). V(S) is then incremented by one for the next I-frame. Receive State Variable V(R): The sequence number of the next I-frame to be received. If the N(S) carried in the next received I-frame does not equal V(R), then a sequence number error has occurred on the logical link and a REJ frame is transmitted with N(R) = V(R). When the next Iframe received carries N(S) = V(R), V(R) is incremented by one. Receive Sequence Number N(R): The receive sequence number carried in all supervisory and Iframes. N(R) acknowledges reception of all I-frames whose N(S) values are less than N(R). The value of N(R) is equal to the value of V(R) when the carrying frame is prepared for transmission. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 67 of 168 2.0, 05/00, page 68 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Section 4 Communication Control Operation 4.1 Initialization The external microprocessor must perform the following initialization sequences in order to operate the HD64541. 4.1.1 Reset Operation Hardware Reset: Reset the HD64541 by applying a low level to input pin 5(6 for at least 24 clock cycles. Table 4-1 shows the initial values of the registers immediately following reset. After hardware reset, HD64541 enters "waiting for RSET command" state, and accepts only STAC or RSET commands. Table 4-1 Register Value at Reset Register Value CR Cannot be reset SR $00000000 ISR $00 IMR $3F CMSR $00 External Memory Area Codes: An area code is a two-bit value that is placed on the system bus by the HD64541 during DMA operations when the external microprocessor is the H16. HD64541 external memory tables are classified into three storage types that may be segregated by area code. Using the STAC command, the external microprocessor informs the HD64541 of the values to be associated with AC0, AC1, and AC2. This must be done after hardware reset and before software reset. Table 4-2 shows which tables are accessed with which ACn value. Table 4-2 Area Codes and Tables Area Code Read Access Write Access AC0 SYSPT, REJIT SYSDT, LOGT, REJIT AC1 SIIT, ESII, RBIT, SUXIT SIIT, SUXIT, RBIT AC2 SDB RDB Software RESET Command: On a RESET command from the external microprocessor, the HD64541 is given the external memory address of the SYSPT table, which it then immediately reads. SYSPT contains system operating parameters that apply to the logical link supported by the HD64541. Changes made to SYSPT after a RESET have no effect until the next RESET. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 69 of 168 4.1.2 Establishment of Operating Mode Three bits, M0, M1, and M2, control the operating mode of the HD64541. They are set by command (OMDS) from the external microprocessor. The three bits individually specify online/offline, local loopback, and auto echo functions. In combination, these bits provide for eight operating modes, as described in table 4-3. Figure 4-1 compares local loopback and local loopback with auto echo. If a flag sequence is received when HD64541 aceepts OMDS command for an online mode, it reports flag synchronization (FSYC) status to the external microprocessor. Table 4-3 Operation Mode Description Mode M2 M1 Normal Local loopback mode M0 Line Interface Host MPU Application Online Frame transmission/reception is possible Normal operation Offline T: Transmits 1s (mark) No frame transmit/receive continuously operations performed (Valid commands for this mode are R: Receive operation shown in appendix D) stops Network operation stops Online T: Transmits 1s (mark) Transmitter is internally looped Internal loopback continuously back to the receiver so that the test transmit bit stream is not sent R: Receive operation to the physical line. Frames stops received from the external microprocessor by the HD64541 for transmission to the remote are looped back internally and given back to the external microprocessor as though received from the remote. These looped-back frames are processed by inverting command/response and recalculating the FCS. In local loopback, all 1s are transmitted over the physical line to the remote and any bits received over the physical line from the remote are discarded. (TXC is provided.) Offline No frames are transmitted/received (Valid commands for this mode are shown in appendix D) 2.0, 05/00, page 70 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Table 4-3 Operation Mode Description (cont) Mode M2 M1 M0 Auto echo Online mode Offline Local loopback and auto echo Line Interface Host MPU Application The receiver is automatically looped back to the transmitter. Goes to offline condition (In this case, RXC is not used. TXC is used as RXC. Phase relation between RXD and TXC satisfies that between RXD and RXC shown in figure 5-7) No frames are transmitted/received (Valid commands for this mode are shown in appendix D) Remote loopback test from remote station to local station Online Transmitter is internally looped • back to the receiver so that the transmit bit stream is not sent • to the physical line. Frames received from the remote are transmitted back to the remote with no change. Offline No frames are transmitted/received (Valid commands for this mode are shown in appendix D) Internal loopback test Remote loopback test from remote station to local station Notes: 1. In loopback mode, frames presented to the HD64541 by the external microprocessor for transmission to the remote have their C/R bits reversed, FCS calculated, and then are processed as though they had been received from the remote. 2. Precautions for modifying the line loop state: When the loopback control bits M1 and M2 are changed while M0 continues to specify online, only the loopback state is changed. The HD64541’s internal states are not changed and may result in unpredictable protocol behavior after the loopback states are restored to normal operation. To prevent this, if the loopback modes are entered while online, the external microprocessor must reset the HD64541’s internal states by forcing M0 through a transition to offline and then back online. See note 3 concerning the implications of doing this on receive data buffer handling. 3. Locating the next receive data buffer: The RBIT table contains a list of descriptors (RBIs) of empty receive data buffers that the HD64541 may use. It normally steps through the RBIs in order, keeping track of which one is next through an index value saved at the beginning of the RBIT. If the HD64541 goes through an offline to online transition, the index is reinitialized to zero so that the next receive data buffer used will be the one whose RBI appears first in the RBIT. This means that the external microprocessor must rebuild the RBIT before effecting an offline to online transition. A mode change command (OMDS) that does not make an online/offline transition does not reset the RBIT index. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 71 of 168 Local loopback Local loopback with auto echo HD64541 HD64541 TXD TXD All 1s RXD RXD Receive operation stops FCS is calculated FCS is calculated FCS is not calculated Figure 4-1 Local Loopback and Local Loopback with Auto Echo Local station Host MPU External memory Remote station HD64541 Set table Hardware reset • STAC command • Set area code RSET command • Reset command SYSPT table load • Load system parameters OMDS command • Set operation mode RBIT table load • Load receive buffer information Receive flag sequence FSYC status Figure 4-2 Initialization Routine 2.0, 05/00, page 72 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library , , ,, Figure 4-2 illustrates the process described in this section. Figure 4-3 shows the HD64541’s state transitions during initialization. STAC command Waiting for RSET command RSET command RSET command Offline Hardware reset: Low applied to RES pin for 24 or more clock cycles Notes: 1. 2. , OMDS command Online indicates hardware reset: low signal to RES pin for at least 24 clock cycles. Only STAC and RSET commands are valid in "waiting for RSET command" state. Figure 4-3 HD64541 Initialization State Transitions 4.2 Establishment and Release of Logical Link The LAPB elements of the procedure described below are illustrated by the sequence diagrams in appendix C. Refer to CCITT recommendations. 4.2.1 Establishing a Logical Link A logical link is established by a SABM/UA exchange or a SABME/UA exchange. Either the local or remote station can initiate the procedure by transmitting SABM/SABME. Transmission of SABM/SABME by the Local Station: To establish a logical link, the external microprocessor sends a DESR command to the HD64541. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 73 of 168 For each DESR command, the HD64541: 1. Transmits a SABM/SABME (P = 1) command frame to the remote 2. Resets the logical link’s internal state machine 3. Resets the logical link’s retransmission counter 4. Starts timer T1 5. Posts normal command completion (CMSR2-CMSR0 = 000) to the external microprocessor On reception of a UA (F = 1) response frame from the remote station, the HD64541 does the following: 1. Stops timer T1 2. Resets internal state variables V(R), V(S), and V(A) to 0 3. Posts DESI status to the external microprocessor (see figure C-2 of appendix C) Receipt of SABM/SABME by the Local Station: First, the external microprocessor sends a DESW command to the HD64541. On reception of a SABM/SABME (P = 1/0) command frame from the remote station, the HD64541: 1. Transmits a UA (F = P = 1/0) response frame to the remote station 2. Resets internal state variables V(R), V(S), and V(A) to 0 3. Posts DESI status to the external microprocessor (see figure C-3 of appendix C) Receipt of DM Response by the Local Station (F = 0 for X.25 mode only): First, the external microprocessor sends a DESW command to HD64541. On the reception of a DM response to request link-set, the HD64541 does the following: 1. Transmits a SABM/SABME (P = 1) command frame to the remote station 2. Resets the logical link's internal state 3. Resets the logical link's retransmission counter 4. Starts timer T1 On reception of the DM (F = 0) response frame from the remote station, the HD64541 does the following: 1. Stops timer T1 2. Resets internal state variables V(R), V(S), and V(A) to 0. 3. Posts DESI status to the external microprocessor (see figure C-3 in appendix C) 2.0, 05/00, page 74 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 4.2.2 Logical Link Release A logical link is released by a DISC/UA exchange. Either the local or remote station can initiate the procedure by transmitting DISC. Transmission of DISC by the Local Station: On command (DRLR) from the external microprocessor, the HD64541 does the following: 1. Transmits the DISC (P = 1) command frame to the remote station 2. Starts timer T1 3. Resets the retransmission counter to 0 4. Posts normal command completion (CMSR2-CMSR0 = 000) to the external microprocessor On reception of the UA (F = 1) or DM (F = 1) response frame from the remote station, the HD64541 does the following: 1. Stops timer T1 2. Returns the logical link to the link release state 3. Posts DRLI status to the external microprocessor (see figure C-2 in appendix C) Receipt of DISC by the Local Station: On reception of a DISC (P = 1/0) command frame from the remote station, the HD64541 does the following: 1. Transmits a UA (F = P = 1/0) response frame to the remote station 2. Posts DRLI status to the external microprocessor (see figure C-3 of appendix C) 4.2.3 Timer T1 Runout T1 Runout on Transmission of SABM/SABME: When the HD64541 initiates the logical link establishment procedure by transmitting SABM/SABME (P = 1) to the remote station, it expects the UA (F = 1) or DM (F = 1) response within time interval T1. If the response frame does not arrive before T1 runs out, SABM/SABME (P = 1) is retransmitted. The T1 runout/SABM(or SABME) retransmit cycle is permitted to continue for N2 times before the HD64541 gives up and posts system recovery request 2 (SRC2) status to the external microprocessor. See figure C-4 of appendix C. T1 Runout on Transmission of DISC: When the HD64541 initiates the logical link release procedure by transmitting DISC (P = 1) to the remote station, it expects the UA (F = 1) or DM (F = 1) response within time interval T1. If the response frame does not arrive before T1 runs out, DISC (P = 1) is retransmitted. The T1 runout / DISC retransmit cycle is permitted to continue for N2 times before the HD64541 gives up and posts system recovery request 2 (SRC2) status to the external microprocessor. See figure C-5 of appendix C. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 75 of 168 4.2.4 Independent Link Disconnection If, after establishing a link, there is no response from the remote station to the transmission of an Iframe (for I-frame transmission, see section 4.3.1), the HD64541 transmits to the remote station a RR frame (P = 1) after occurrence of a T1 runout. If T1 runout occurs N2 times in T.90 mode, HD64541 notifies the external microprocessor of system recovery request 2 status (SRC2) and releases the link. If T1 runout occurs N2 times in X.25 or X.75 mode, the HD64541 transmits a SABM/SABME frame (P = 1) to the remote station and at the same time notifies the external microprocessor of system recovery request 2 (SRC2) status and reset link (LRST) status. If after an SABM/SABME frame transmission timer T1 runout occurs N2 times, the HD64541 notifies the external microprocessor of system recovery request 2 status (SRC2). See figure C-6 of appendix C. 4.3 Data Transmit and Receive 4.3.1 I-Frame Transmission The external microprocessor prepares an information field for transmission to the remote station by placing it in a transmit data buffer (SDB) in external memory and loading its buffer descriptor entry into the SIIT (for I-frames) or the SUXIT (for UI, XID and TEST frames). A subsequent DDR1 or DDR2 (for I-frames) or MUDR (for UI, XID and TEST frames) command from the external microprocessor directs the HD64541 to transmit. The external microprocessor specifies the number of I-frames to be transmitted as a parameter in the DDR1 or DDR2 command. The HD64541 manages I-frame sequence numbering, acknowledgement handling, error detection, and retransmission without further intervention from the external microprocessor. Figure 4-4 shows the structure and interrelationship of the tables that participate in the transmission process. Preparing I-Fields for Transmission in I-Frames: I-fields to be carried in I-frames transmitted to the remote station are prepared by the external microprocessor in transmit data buffers (SDBs). The addresses and byte counts of the SDBs are stored into consecutive buffer descriptor entries (SIIs) in the SIIT table in the order they are to be transmitted. The first SII that may be used by the external microprocessor to do this is identified by the index NSIIN, which is the first byte of the SIIT. 2.0, 05/00, page 76 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Each buffer descriptor also contains a data chaining indicator and a pointer to an extension buffer descriptor (ESII). If data chaining is active, then the SDB identified by ESII contains a continuation of the I-field. The format of the ESII is identical to that of the SII, containing the address and byte count of a data buffer, a chaining indicator, and a pointer to another ESII. I-fields of arbitrary length may then be composed of any number of noncontiguous SDBs and chained together for transmission. Using NSIIN: NSIIN is the first byte of the SIIT. It is an index to the buffer descriptor (SII) entries. Updated by the HD64541 and referenced by the external microprocessor, NSIIN is used to manage the list of outbound I-fields to be transmitted in I-frames to the remote station. 1. When the external microprocessor has additional I-frames that it wants transmitted, the value of NSIIN identifies the first SII buffer descriptor entry that it may use to store the addresses and byte counts of the transmit data buffers (SDBs). The external microprocessor is not allowed to change the value of NSIIN and must use some other means to keep track of the SII entries when more than one frame is added to the transmit list. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 77 of 168 Reset command (RSET) SUXIT starting address Sending U,X frame information table (SUXIT) . . . SYSPT starting address System parameter table (SYSPT) SAD ... . . . SUXI SIIN = 1 SDB starting address Common byte . . . ... SIIT starting address Transmit data buffers (SDB) SDB starting address Sending I-frame information table (SIIT) SUXITA SIITA SUXI SUXIN = 0 SII SIIN = 0 SAD SDB starting address CD CTAD ESII starting address Extended sending I-frame information (ESII) ... SAD SII SIIN = 1 CD CTAD Each SIIT consists of common bytes and an NSI number of SIIs. The end of the table depends on the value of NSI. Figure 4-4 Relation between Transmission Tables Rev. 2.0, 05/00, page 78 of 168 ICminer.com Electronic-Library Service CopyRight 2003 Next ESII 2. NSIIN is updated by the HD64541 as follows: a. NSIIN is initialized to 0 when: i. The HD64541 changes from offline to online mode on a OMDS command from the external microprocessor ii. The logical link is established and DESI status is posted iii. The logical link is released and DRLI status is posted b. NSIIN is incremented by FN on a valid DDR1 or DDR2 command from the external microprocessor. DDR1 and DDR2 direct the HD64541 to transmit the next FN buffers whose descriptors start at the one identified by NSIIN. CMSR = 000 status is posted after NSIIN is incremented. c. NSIIN remains unchanged if the DDR1 or DDR2 commands turn out to be invalid and CMSR ≠ 000 status is posted. SIIT is effectively a circular buffer containing SIIs and uses NSIIN as its index. 3. While the value of NSIIN is automatically incremented by FN, the number of additional Iframes to be transmitted on the DDR1 or DDR2 command, in case of errors, the external microprocessor should check that the command completion status is CMSR = 000 before generating the next DDR1 or DDR2. Releasing the Data Buffers of Acknowledged Frames: When acknowledgement is received from the remote station for transmitted I-frames, the HD64541 notifies the external microprocessor by posting status ACIF. The ASIIN value in the SIIT is then the index of the buffer descriptor (SII) for the last acknowledged frame. The external microprocessor then, by comparing the current value of ASIIN with the value at the time of the previous ACIF status, implicitly knows how many frames have been acknowledged. Because the SII entries in the SIIT behave like a circular buffer, a modulo value equal to the number of SIIs must be considered when comparing ASIIN values. The value of ASIIN accompanying ACIF status may be used to determine the number of newly acknowledged I-frames. The difference between the ASIIN posted with the current ACIF is the number of I-frames acknowledged since the previous ACIF. If the current ACIF status is the first one since the logical link was (re)established, then ASIIN + 1 is the number of I-frames acknowledged. Transmit data buffers may be released and their corresponding descriptor entries (SIIs) may be reused in the following cases: 1. Buffers identified by the ACIF status as having been acknowledged by the remote station. 2. All active buffers on a RSET or OMDS command which instructs the HD64541 to go to the offline mode from the online mode. 3. All active buffers when the logical link is released before it receives acknowledgement and DRLI status is posted. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 79 of 168 4. All active buffers when the logical link is reestablished and DESI status is posted. Differences between DDR1 and DDR2 Commands: The DESI status posted following logical link reestablishment will report whether any unacknowledged I-frames were outstanding so that the external microprocessor can reschedule them for transmission. If the external microprocessor chooses to ignore DESI, it will not know of the unacknowledged frames, which are then lost. DDR1 and DDR2 provide a convenient way of preventing this. The DDR1 command is invalid immediately following the posting of DESI status while DDR2 is not restricted. DDR1 and DDR2 are identical otherwise. If the DESI status is ignored, the next DDR1 command results in the posting of CMSR = 100 status, forcing the external microprocessor’s attention to the fact that DESI was posted. At least one DDR2 command must then be executed before DDR1 becomes a valid command again (figure 4-5). 2.0, 05/00, page 80 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Local station Local station Host MPU HD64541 Remote station Host MPU HD64541 Remote station I-field DDR2 DDR2 I(2) I(3) DESI UA I(1) DDR1 SABM ✕ DDR2 I(0) DDR1 I(1) DDR2 DDR2 DDR1 I(0) ✕ I(2) SABM ✕ DDR1 I(3) DESI UA DDR1 ✕ I(0) DDR2 DDR2 I(1) I(2) a) I(2) and I(3) were unacknowledged when the logical link was reestablished. Because the external microprocessor chooses to ignore the DESI status, it does not know enough to reschedule them for transmission. CMSR = 100 Command unexecutable DDR2 ➂ I(0) b) Situation is identical to a) except that DDR1 is used instead of DDR2. The DDR1 command immediately following DESI is rejected by the HD64541 as invalid. The external microprocessor is thereby forcibly notified that DESI was posted and is given the opportunity to reschedule the unacknowledged frames for transmission in the newly established session. One execution of DDR2 makes DDR1 valid again. Figure 4-5 Use of DDR1 to Force Notice of DESI Status 4.3.2 Transmitting UI, XID, and TEST Frames Transmittable Frames: The external microprocessor may request the transmission of UI, XID, or TEST commands or responses and arbitrarily set the values of the P/F bit. Bit 2 of the PMODE in the SYSPT must be set to 1 for transmitting these frames. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 81 of 168 Preparing I-Fields for Transmission in UI, XID, and TEST Frames: I-fields to be carried in UI, XID or TEST frames transmitted to the remote station are prepared by the external microprocessor in transmit data buffers (SDBs). The addresses and byte counts of the SDBs are stored into consecutive buffer descriptor entries (SUXIs) in the SUXIT table in the order they are to be transmitted. The first SUXI that may be used by the external microprocessor to do this is identified by the index NSUXIN, which is the first byte of the SUXIT. The frame type, command/response indicator, P/F bit value, and G bit value are specified for each frame in the SUXI. Unlike I-frames, UI, XID, and TEST frame I-field data chaining is not supported by the HD64541. The entire I-field to be transmitted must fit within one SDB. NSUXIN is the first byte of the SUXIT and is an index to the buffer descriptor (SUXI) entries. Updated by the HD64541 and referenced by the external microprocessor, NSUXIN indicates to the external microprocessor which SUXI may be used next to load a descriptor for an outgoing UI, XID, or TEST frame. NSUXIN is updated by the HD64541 as follows: 1. NSIIN is initialized to 0 when the HD64541 changes from offline to online mode on an OMDS command from the external microprocessor. 2. NSIIN is incremented by 1 on a valid MUDR from the external microprocessor. MUDR directs the HD64541 to transmit the buffer whose descriptor is identified by NSUXIN. CMSR = 000 status is posted after NSUXIN is incremented. Note that unlike DDR1 and DDR2, which initiate a specifiable number of I-frame transmissions, MUDR initiates only one UI, XID or TEST frame transmission per execution. 3. NSUXIN remains unchanged if the MUDR command turns out to be invalid and non-zero CMSR status is posted. SUXIT is effectively a circular buffer containing SUXIs that uses NSUXIN as its index. Releasing the Data Buffers of Transmitted UI, XID, and TEST Frames: UI, XID, and TEST frames are unnumbered and therefore not subject to the acknowledgement and retransmission procedures performed on I-frames. As soon as the UI, XID, or TEST frame has cleared the transmitter, its buffer may be released. HD64541 posts status TAUF to notify the external microprocessor of this. Global Address: A global address can be assigned to UI, XID, and TEST frames by setting G=1. 2.0, 05/00, page 82 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 4.3.3 Receiving Frames that Contain I-Fields The procedures specified here apply to frames that may carry I-fields, regardless of whether such a frame actually carries one or not in a particular case. Frames in which an I-field is not permitted are not explicitly made available to the external microprocessor. Receive procedures for I-fields use a table (RBIT) containing some configurable number (NRBI) of input data buffer descriptors (RBIs) that specify the address and size of receive data buffers (RDBs). These memory locations are prepared by the external microprocessor for use by the HD64541. Figure 4-6 shows the structure. Reset command (RSET) Receive buffer information table (RBIT) SYSPT starting address . . . RBI RBIN = 0 Receive data buffers (RDB) System parameter table (SYSPT) RAD . . . . . . RBI RBIN = 1 RBITA . . . RBIT starting address Figure 4-6 (a) Relation between Reception Tables Note that only one RBIT exists for the HD64541. All I-frames, UI frames, XID frames, and TEST frames are received through the one RBIT. This means that the external microprocessor has to sort the frames by type after they have been received. Preparation of Receive Data Buffers: The external microprocessor allocates empty receive data buffers (RDBs) and loads their addresses and sizes into receive data buffer descriptors (RBIs). A flag (BS) in each RBI indicates to the HD64541 whether the RBI describes an empty buffer. The flag is toggled when the associated buffer is filled by the HD64541. The RBIT is a table containing some configurable number of RBIs. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 83 of 168 Index RBIN in the RBIT specifies the next RBI that the HD64541 will examine when looking for an empty buffer to hold an incoming I-field. The HD64541 increments RBIN as it fills each buffer, so that the RBIs are used sequentially from the lowest number. RBIN is initialized to 0 on a transition from offline to online mode. After the last RBI in the RBIT has been used, the HD64541 cycles back to the RBI in RBIN = 0. The buffer status bit prevents a buffer from being reused before the external microprocessor has unloaded it. Frame Receive Operation: When a valid frame containing an I-field is received, the HD64541 locates the next empty receive data buffer and fills it by DMA. Header information (frame type, P/F) is written into octets 0 to 4 of the RBI when the frame has been completely received. FREC status is posted once per frame to notify the external microprocessor (see figure 4-6 (b)). 2.0, 05/00, page 84 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library HD64541 internal buffer RBIT RBIN = 0 RBIN = 1 RBIN = 2 BS = 1 1 BS = 1 2 BS = 1 1. At initialization, HD64541 fetches three receive buffers from RBIN = 0 through RBIN = 2. 0 2. When a frame is received, it uses the RBI in RBIN = 0, and fetches the next RBI in RBIN = 3. 1 1 2 3 BS = 1 , RBIN = 3 RBIN = 4 RBIN = 5 RBIN = 6 RBIN = 7 4 BS = 0 2 3 BS = 1 BS = 1 3. BS = 1 (NRBI = 8) After it uses the RBI in RBIN = 1, it will fetch the RBI in RBIN = 4. Since BS = 0, however, it can't fetch that RBI and has only two receive buffers. 4. Following use of RBIN = 2, it doesn't fetch the RBI after RBIN = 4, leaving only one receive buffer. 2 3 3 After it uses the remaining one receive buffer, it enters the internal busy state. In order to make it possible to exit the internal busy state, the external microprocessor must prepare three empty receive buffers by setting BS = 1 of the RBI in RBIN = 4. Figure 4-6 (b) Example to Fetch the Receive Buffer If the received frame does not fit into a single buffer, data chaining is invoked. The HD64541 automatically steps to the next RBI and continues filling the new buffer. Data chaining can continue up to the maximum I-field size permitted or until no more buffers are available. For data chained frames, header information is written into the RBI of the starting buffer only. Successive RBIs contain only BS and CD indicators. FREC status is posted once for the entire chain (see figure 6-4 (c)). Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 85 of 168 If the received frame has a bad FCS, the buffers are reused and RBIN is not updated. If the HD64541 receives any I-, UI, XID, or TEST frame whose I-field length is 0 byte, it will normally proceed by using a single receive data buffer (RDB). When No Empty Receive Data Buffer is Available: If the HD64541 cannot locate an empty receive data buffer when an I-field is received, it is automatically placed in busy state. The HD64541 sends RNR to notify the remote of its inability to receive and post an internal busy interrupt to the external microprocessor (ISR4 = 1). The HD64541’s internal buffer handling mechanism requires at least three empty receive buffers to avoid an internal busy condition. During the internal busy condition, receipt of an I-, UI, XID, or TEST frame is processed as follows: 1. If receive buffer length ≥ I-field length of received frame a. The I-frame is discarded in accordance with protocol (See note). If the I-field length of the received frame is longer than N1B, N1 error occurs. b. UI, XID or TEST frame will be received normally. However, if the I-field length of the received frame is longer than N1B, N1 error occurs. 2. If receive buffer length < I-field length of received frame I-, UI, XID, or TEST frames are discarded and ISR3 (receive buffer overflow) is set. However, if receive buffer length is equal to or longer than N1B, N1 error occurs and ISR3 is not set. Note: If an I-frame is received when the HD64541 is not busy but only one receive buffer is available, it is placed in busy state after the receive buffer is used up; consequently, it receives the I-frame correctly. Receive frame F FCS I RDB (RBIN = 0) C A RDB (RBIN = 1) F , Free Figure 4-6 (c) Receive Buffer Chain 4.3.4 Transmitting and Receiving I-Frames Transmitting I-Frames: On reception of a valid DDR1 or DDR2 command from the external microprocessor, the HD64541 queues the specified number of I-frames (FN) for transmission. It immediately posts normal command completion with status CMSR0-CMSR2 = 000. 2.0, 05/00, page 86 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library It actually transmits the I-frames in queue sequence as the flow control state allows. Frames that have been queued earlier but not yet transmitted go first. If the transmit window has closed, the remote station has signaled RNR busy, or transmitter timer recovery or REJ procedures are in progress, the new I-frames are held pending. As each frame comes up for transmission, the current values of the state variables V(S) and V(R) are assigned as the outgoing frame’s N(S) and N(R), respectively. Timer T1 is started or restarted as each frame is sent. As acknowledgements are received from the remote station, state variable V(A) is updated to the latest N(R) received and timer T1 restarted. T1 stops when no more unacknowledged transmitted frames are outstanding on the logical link. The HD64541 conveys the acknowledgements to the external microprocessor as they come in by posting ACIF status. Each ACIF specifies an index value ASIIN that identifies the SII transmit buffer descriptor corresponding to the last frame acknowledged. See figure C-7 of appendix C. If FN (number of I-frames) is set to value greater than or equal to 2 and either I-frame transmission command DDR1 or DDR2 is issued, or FN number of I-frames can be continuously sent. Here, the interval between frames is set with bit 4 of OMODE in SYSPT. Receiving I-Frames: When a valid I-frame is received from the remote station, the HD64541 writes its I-field into the current receive data buffer (RDB). The current RDB is the one whose descriptor (RBI) is identified by the index RBIN in the RBIT table. State variable V(R) is incremented by one, and FREC status is posted to notify the external microprocessor of the RBI/RDB that now contains a newly received I-frame. If the HD64541 is in a local station busy state, the received frame is discarded and nothing is reported to the external microprocessor. The HD64541 sends a response to the remote station as follows: 1. When P bit is set to 1: If the local station is not in a busy state, it sends an RR response with the F bit set to 1. If it is in a busy state, it sends an RNR response with the F bit set to 1. 2. When P bit is set to 0: If no I-frame is available for transmission, the local station transmits an RR response with the F bit set to 0 after T2 period. If an I-frame is available for transmission, the local station transmits the I-frame with the value of N(R) set to the current value of V(R). If the local station is in a busy state, it transmits an RNR response with the F bit set to 0. Simultaneous Transmission and Reception of I-Frames: In each direction of transmission, Iframes carry an N(R) that acknowledges reception of I-frames in the opposite direction. See figure C-8 of appendix C. Accordingly, the HD64541 may post ACIF status in addition to FREC on reception of an I-frame. ACIF is posted only on I-frames that acknowledge previously unacknowledged frames. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 87 of 168 4.3.5 Receiving REJ Frames On reception of a valid REJ supervisory frame from the remote station, the HD64541 sets its state variables V(S) and V(A) to the N(R) value carried in the REJ. It stops timer T1, and retransmits all outstanding I-frames starting with the one identified by the received N(R). See figure C-9 of appendix C. Outstanding I-frames with N(S) less than the received N(R) are considered acknowledged and ACIF is posted to the external microprocessor. 4.3.6 T1 Runout Timer T1 limits the amount of time the remote station is allowed in returning an acknowledgement for an I-frame sent to it. T1 is started (or restarted) by the transmitting station as each I-frame is transmitted, and stopped when all outstanding frames have been acknowledged. If T1 expires, the HD64541 increments its retransmission counter N2, restarts T1, and transmits an RR (P = 1) command to solicit a response. RR (P = 1) is retransmitted on every T1 expiration until either the retransmission count has reached the maximum value specified in SYSPT or when a valid supervisory response frame with F = 1 is received. In X.25 and X.75 mode if N2 reaches the maximum value without receiving the required response, SRC2 and LRST status are posted to the external microprocessor and an attempt is made to reestablish the logical link by sending SABM/SABME (P = 1). See figure C-6 of appendix C. The timer recovery condition is cleared when a valid supervisory frame is received from the remote station with F = 1. The N(R) carried in that frame identifies the last I-frame that the remote station correctly received. If that N(R) is less than the HD64541’s V(S), it means that frames were lost and need to be retransmitted. In this case, the HD64541 sets its V(S) to the received N(R). In T.90 mode if N2 reaches the maximum value SRC2 status is posted to the external microprocessor and the HD64541 releases the logical link. 4.3.7 T3 Runout When the HD64541 is in on-line mode and the receive data changes to idle pattern from flag sequence, timer T3 starts. If a T3 runout then occurs, the HD64541 reports idle detection status (IDET) to the external microprocessor. However, if the receive data returns to flag sequence before T3 runs out, the HD64541 stops timer T3 without notifying the external microprocessor. Figure 4-7 shows the relation between the set operating mode command, receive data state, and status to be reported. 2.0, 05/00, page 88 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library The HD64541 processes a command issued from the external microprocessor in the same manner as a flag sequence even if the receive data is the idle pattern. The T3 timer can be also used in transparent mode. The value of T3 is set by T3 of SYSPT and the timestep of T3 is set by bit 1 of PMODE in SYSPT. 4.4 Link Reset The HD64541 automatically reestablishes the data link in any of the following cases (after reestablishing the data link, it notifies the external microprocessor of reset link status (LRST)): a. When SABM/SABME is sent in return for receiving FRMR b. When SABM/SABME is sent due to an N2 number of T1 runouts (in X.25 or X.75 mode) c. When SABM/SABME is sent in return for receiving an unexpected supervisory frame with F = 1 (in X.25 mode) d. When SABM/SABME is sent in return for receiving an unexpected UA or DM response (in X.25 mode) Figure C-6 (a) and C-10 (a) in appendix C shows examples of b, c, and d above, respectively. Command OMDS (off-line to on-line) Operating mode off-line OMDS OMDS OMDS (on-line to on-line) (on-line to off-line) (off-line to on-line) on-line off-line RUN Timer T3 START STOP START OUT on-line START STOP Flag Receive data state ldle , Status FSYC IDET FSYC FSYC FSYC Figure 4-7 Relation between OMDS Command, Receive Data State, and Report Status Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 89 of 168 4.5 Exception Condition Handling 4.5.1 N(S) Sequence Error When the HD64541 receives an I-frame that is out of sequence but otherwise valid from the remote station, its I-field is discarded and a REJ frame sent back to solicit the expected I-frame. The I-fields of any subsequent I-frames are similarly discarded until the expected one is received. The N(R) field carried in the out-of-sequence frame is considered a valid acknowledgement, however, and is not discarded. An I-frame is out of sequence when its N(S) does not match the receiving station’s V(R) state variable. The REJ frame sent back carries N(R) = V(R). The remote station is obliged to retransmit all outstanding I-frames beginning with the one identified by the N(R) value in the REJ. See figure C-11 of appendix C. 4.5.2 N(R) Sequence Error When the HD64541 receives an N(R) value from the remote station that acknowledges more Iframes than have been transmitted and are outstanding, the HD64541 posts the remote station system recovery request (YRCV) status to the external microprocessor and transmits FRMR. The N(R) received must be greater than or equal to state variable V(A) and less than or equal to state variable V(S) to be valid. The comparison is done in the specified modulo (8 or 128). See figure C-12 of appendix C. 4.5.3 Busy States Local Station Busy State: The HD64541 may enter the local station busy state either as a result of its internal protocol processing or on command from the external microprocessor. Command SSBY sets busy the logical link. Busy state set by SSBY can be released only through RSBY. See figure C-13 of appendix C. When the HD64541 enters the busy state through internal protocol processing, it notifies the external microprocessor through interrupt ISR4 = 1. When it exits busy state, it posts interrupt ISR4 = 0. When the HD64541 becomes busy by whatever means, it transmits RNR to the remote station and transmits RR when the busy condition is released. During busy, frames from the remote station are processed as follows: 1. The I-fields of all I-frames are discarded 2. RNR (F = 1) is transmitted in response to an I-frame with P = 1 3. All supervisory responses and commands with P = 0 are handled normally 4. RNR (F = 1) is transmitted in response to a supervisory command with P = 1 2.0, 05/00, page 90 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library In all four cases, normal acknowledgement processing procedures apply to the received N(R). Remote Station Busy State: When the HD64541 receives a valid RNR frame from the remote station, it enters the remote station busy state for the logical link and reports it to the external microprocessor by posting SRBY status. In the remote station busy state, the HD64541 does not transmit or retransmit I-frames. It posts RRBY when the remote station exits the busy state and sends a notifying RR frame. The HD64541 polls the remote station at intervals of T1 to make sure that the remote station reports any change in busy status. As soon as RNR is received, the HD64541 starts timer T1. On the expiration of T1, it transmits RR (P = 1) to demand either RR (F = 1) or RNR (F = 1). See figure C-14 of appendix C. In T.90 mode, on reception of the RNR (F = 1) while in the timer recovery state, HD64541 remains in this state. If T1 runouts have repeated N2 times and the remote station has not released the remote station busy state, HD64541 posts system recovery request SRC2 and releases the logical link. (see figure C-14 (b) in appendix C) 4.5.4 Receipt of Unexpected Frames Unexpected frames are defined as follows. a) Supervisory frames (F = 1) in timer recovery state and supervisory frames which are not responses to command frames (P = 1) b) UA and DM response frames which should not be sent by the remote station (1) Receipt of unexpected frames in X.25 mode HD64541 sends an SABM/SABME frame to the remote station and posts LRST status to the host processor. (See figure C-10 (a) in appendix C.) (2) Receipt of unexpected frame in X.75 mode HD64541 sends an FRMR frame to the remote station and posts YRCV status to the host processor. (See figure C-10 (b) in appendix C.) (3) Receipt of unexpected frame in T.90 mode HD64541 ignores the frame and discards it. HD64541 counts it as a process error in the statistical information logging table. (See figure C-10(c) in appendix C.) Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 91 of 168 4.5.5 Receipt of I-frame with Invalid N(S) N(S) is invalid if it is equal to the receive state variable V(R), and is also equal to the last N(R) transmitted to the remote station plus K, the maximum outstanding I-frame number. (1) On receipt of frame with invalid N(S) in X.25 mode Since an invalid N(S) is not defined in the CCITT X.25 recommendation, HD64541 receives the I-frame with an invalid N(S) as a correct frame by acknowledging N(S) as equal to V(R). (See figure C-15 (a) in appendix C.) (2) On receipt of frame with invalid N(S) in X.75 mode HD64541 discards the I-frame and transmits an FRMR frame to the remote station and posts YRCV status to the host processor. (See figure C-15 (b) in appendix C.) (3) On receipt of frame with invalid N(S) in T.90 mode HD64541 discards the information field of this I-frame and transmits an REJ frame to the remote station and promotes the recovery from this state. (See figure C-15 (c) in appendix C.) 4.6 Transparent Mode This section describes how to use transparent mode. Transparent Mode: • Transmit: Data prepared by the external microprocessor is grouped with flags and FCS and then transmitted. • Receive: Bit sequence between a flag and FCS is received as data. Frame Flag FCS Data Figure 4-8 Frame in Transparent Mode 2.0, 05/00, page 92 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Flag Tables • SYSPT Table 4-4 shows bytes used in transparent mode. Others are set to 0. Table 4-4 SYSPT Used in Transparent Mode Name Byte Bit Description PMODE 0 3 Set as in normal mode. 7 Set to 1 (transparent mode) OMODE 1 0 Set to 1 VADD 2 0 to 7 Set as in normal mode TDIV 3 0 to 3 T3 12 0 to 7 NRBI 13 0 to 7 NSI 15 0 to 7 S I I TA 25,26,27 0 to 7 RB I TA 29,30,31 0 to 7 Set as in normal mode • SIIT Data is set in the table the same as in normal mode. 0 should not be set for SBC. • RBIT The RBIT used in transparent mode is shown in table 4-5. Table 4-5 RBIT Used in Transparent Mode Table Byte Bit Description RBC 2 0 to 5 Number of bytes in data section of received frame 3 0 to 7 BS 4 7 Buffer status used as in normal mode CD 4 6 Chained data used as in normal mode TYP 4 0 to 2 000 RBS 6 0 to 4 Size of receive data buffer 7 0 to 7 9 to 11 0 to 7 RAD Starting address of RDB Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 93 of 168 • LOGT Table 4-6 shows items to be counted. Table 4-6 LOGT Used in Transparent Mode No. Description 0 FCS error 1 Short frame 2 Residual bit frame 3 Abort frame 4 Overrun error 5 Idle 6 Underrun error Command: Ten types of commands used in transparent mode are shown in table 4-7. Table 4-7 Commands Used in Transparent Mode Command Operation STAC,RSET,OMDS CPOL,MPIS,DSPT DERC,SUTD,RETD Same as in normal mode DDR 2 Frame transmission Eight types of commands shown below cannot be used in transparent mode; a command format error will occur if their use is attempted. Inhibited commands in transparent mode: DDR1, MUDR, DESR, DRLR SSBY, RSBY, DESW, RESR Status: Five types of status are used in transparent mode: PITL, TAIF, FREC, IDET, and FSYC. Among these, TAIF is valid only in transparent mode. The functions of PITL, FREC, IDET, and FSYC others are the same as in normal mode. 2.0, 05/00, page 94 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library Typical Sequence Example: Figure 4-9 shows a typical sequence diagram. External CPU HD64541 Remote station RSET OMDS FSYC DDR2 Frame TAIF Frame FREC Figure 4-9 Typical Sequence Diagram in Transparent Mode Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 95 of 168 4.7 Protocol mode (T.90, X.75, X.25) Protocol mode is selected to T.90, X.75, or X.25 mode by bits 1 to 3 of OMODE on SYSPT. The difference between protocol operations for each mode is shown in table 4-8. Table 4-8 Protocol Mode No Event X.25 layer 2 X.75 layer 2 T.90 layer 2 Reference 1 Receive unexpected S-frame (F = 1) SABM/SABME transmit FRMR transmit Ignore (Procedure error) 4.5.4 Figure C-10 Receive unexpected UA, DM response SABM/SABME transmit FRMR transmit Ignore (Procedure error) Receive I-frame of invalid N(S) Normal receive FRMR transmit REJ transmit 2 Receive DM response Link-setting to request link-set 3 N2-times T1-timeout Start link-reset Enter the disconnected phase 4.2.4 4.3.6 Figure C-6 4 Receive RNR (F = 1) in timer recovery condition End timer recovery condition Remain timer recovery condition 4.5.3 (2) Figure C-14 4.8 Ignore (Procedure error) 4.5.5 Figure C-15 4.2.1 (3) Figure C-3 Fast Transfer Speed The maximum transfer speed of HD64541 is 5 Mbps. However, if the line transmission load to HD64541 is too heavy, such as by receiving short frames continuously, or for reasons due to system architecture, HD64541 will not cover its protocol process. The following cases are described. (1) Continuous frame reception (2) Continuous frame transmission (3) Chain of data buffer (4) Data transfer by DMA from external memory 2.0, 05/00, page 96 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 4.8.1 Continuous Frame Reception When HD64541 receives one frame, it analyzes the frame type and takes appropriate action for state transfer and protocol operation. If during frame processing another frame is on the line, the HD64541 cannot receive this frame correctly and thus ignores it. For normal continuous receipt of frames, HD64541 needs at least approximately 470 µs (see figure 4-9) for one frame period, and approximately 140 µs (see figure 4-9) for flag intervals. (B) Receive line (RXD) F A C FCS F F A C I FCS F F A C FCS F (A) Figure 4-10 Continuous Frame Reception 4.8.2 Continuous Frame Transmission When HD64541 receives an I-frame transmission command (DDR1, DDR2) with FN ≥= 2, HD64541 can transmit I-frames continuously. The minimum interval time between a transmitted frame is approximately 80 µs in normal protocol mode and approximately 60 µs in transparent mode. If the interval of a received flag of the remote station is longer than the interval of a transmitted flag, an error may occur in the remote station. (For example, between two HD64541s, the interval time for reception is approximately 140 µs and the interval for transmission is approximately 80 µs.) To avoid this situation, the user should select the minimum interval transmit flag time as approximately 80 µs or approximately 300 µs by the 4 bits of OMODE in SYSPT. More than 80 µs (1) (OMODE) 4 = 0 1 More than 80 µs 2 More than 80 µs 3 4 Transmit line (TXD) More than 300 µs (2) (OMODE) 4 = 1 1 More than 300 µs 2 More than 300 µs 3 4 Transmit line (TXD) Figure 4-11 Continuous Frame Transmission Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 97 of 168 4.8.3 Chain of Data Buffers Chain operation of data buffers is used to store the I-field of one frame in multiple receive data buffers, or to gather the data stored in multiple transmission data buffers and send them in one frame. When the HD64541 is chaining the data buffer, it prepares the next data buffer after loading to one buffer, which takes about 120 µs. HD64541 has 20 bytes of FIFO for reception and transmission. When the line speed becomes high, if the frames in FIFO become full before the HD64541 can finish the chaining process, a transmission underrun error or receive overrun error will occur. (These errors indicate that the FIFO is empty during transmission or that it is full during transmission.) Also, the capacity of a data buffer is too small, a buffer overflow error or an internal busy state may occur. Set the data buffer size as shown in table 4-9 when data chaining is needed. Table 4-9 Line Speed and Data Buffer Size Line speed 5 Mbps 4 Mbps 2 Mbps Data buffer size More than 75 bytes More than 60 bytes More than 30 bytes 2.0, 05/00, page 98 of 168Service CopyRight 2003 Powered Rev. by ICminer.com Electronic-Library 4.8.4 External Memory and Data DMA Transfer The DMA controller in HD64541 needs 4 cycles to read one word and 5 cycles to write one. This cycle time is constant, so the occupation rate of the host bus must become higher when the line speed is high. When HD64541 transmits and receives I-frames, it requests bus authority (%5(4 = low) to transfer data by DMA from external memory. If for such reason as the MPU does not get bus authority or if there is some delay, a receive overrun error or transmit underrun error may occur in the HD64541. Figure 4-11 shows the relationship of the host-bus operation rate and DMA transfer capability. 10 M 5 Mbps DMA transfer capability (bps) Read Write 1M 100 k Read/Write 10 k 8 kbps 1k 0.01 0.1 1 10 100 Host bus occupation rate (%) Host-bus occupation rate = (b/a) × 100 (%) BACK b a Figure 4-12 Dependency of Host-Bus Occupation Rate on DMA Transfer Capability Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 99 of 168 2.0, 05/00, page 100 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Section 5 Electrical Characteristics 5.1 Absolute Maximum Ratings Table 5-1 Absolute Maximum Ratings Parameter Symbol Power supply voltage VCC (Note 2) (Note 2) Value Unit 7.0 V Input voltage Vin VSS – 0.3 to VCC + 0.3 V Operating temperature Topr 0 to 70 °C Storage temperature Tstg –55 to +150 °C Notes: 1. Permanent LSI damage may occur if maximum ratings are exceeded. Normal operation should be under recommended operating conditions. If these conditions are exceeded, it could affect the reliability of the LSI. 2. With respect to VSS (system ground). 5.2 Recommended Operating Conditions Table 5-2 Recommended Operating Conditions Parameter Symbol Power supply voltage VCC (Note) Min Typ Max Unit 4.75 5.0 5.25 V VIL (Note) –0.3 — 0.8 V Input high level voltage VIH (Note) 2.0 — VCC V Operating temperature Topr 0 25 70 °C Input low level voltage Note: With respect to VSS (system ground). Timing measurement: The timing measurement point for the output low level is defined at 0.8 V throughout this specification. The output low level at stable condition (DC characteristics) is defined at 0.4 V. V VOH VOL at the timing measurement (0.8 V) VOL at the DC level (0.4 V) 0 measurement point t VOL Reference at Timing Measurement Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 101 of 168 5.3 Electrical Characteristics 5.3.1 DC Electrical Characteristics Table 5-3 DC Electrical Characteristics (VCC = 5 V ± 5%, VSS = 0 V, Ta = 0°C to +70°C, unless otherwise noted) Parameter Symbol Input high level voltage VIH Input low level voltage Min Typ* Max Unit Condition CLK (clock) 2.4 — VCC V Others 2.0 — VCC V VIL –0.3 — 0.8 V Input leakage current IIN — — 2.5 µA Output high level voltage VOH 2.4 — — V IOH = –200 µA Output low level voltage VOL — — 0.4 V IOL = 1.6 mA Output leakage current ILOH — — 10 µA Pin capacitance Cp — — 15 pF Vin = 0 V F = 1 MHz Ta = 25°C Current Consumption ICC — * Ta = 25°C, VCC = 5.0 V 2.0, 05/00, page 102 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 26 50 mA 5.3.2 AC Electrical Characteristics Table 5-4 (a) AC Electrical Characteristics (VCC = 5 V ± 5%, VSS = 0 V, Ta = 0°C to +70°C, unless otherwise noted) Normal mode No. Parameter Symbol Min Max Unit Operating frequency f 2 6.25 MHz 1 Clock cycle time tcyc 160 500 ns 2 Clock width low tCL 75 250 ns 3 Clock width high tCH 75 250 ns 4 Clock fall time tcf — 10 ns 5 Clock rise time tcr — 10 ns 6 Asynchronous input set-up time tASI 25 — ns 7 Set-up time from $6 tASS 0 — ns 8 Clock low to 5($'< low tCLR — 120 ns 9 Clock high to ',1, '%(1, $2' valid tCHD — 250 ns 10 Clock low to '%(1 low tCLD — 120 ns 11 5($'< low to '6 high tRLD 0.5 — clocks 12 $6 high to address invalid tAHI 0 — ns 13 '6 high to 5($'< high impedance tDHDH — 140 ns 14 '6 high to '%(1 high impedance tDHBH — 140 ns 15 '6 high to data invalid tDHDI 0 — ns 16 '6 high to 5($'< high impedance tDHRH — 140 ns 16A 5($'< high to high impedance tRHHI 10 — ns 17 Clock high to ',1 low tCHDL — 140 ns 18 Data in to '%(1 low tDIBL 25 — ns 19 Clock low to '%(1 high tCLBH — 100 ns 20 Clock high to ',1 high tCHDH — 140 ns 21 5($'< low to A/D invalid tRLAI 1.0 — clocks 22 Clock high to %5(4 low tCHBL — 150 ns 23 %$&. set-up time from CLK tBSC 30 — ns 24 %$&. low to $,1 low tBLAL 2.5 3.5 clocks 25 Clock high to %5(4 high tCHBH — 150 ns 26 Clock high to $,1 high tCHAH — 90 ns 27 Address valid to $6 low tAVAL 40 — ns Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 103 of 168 Table 5-4 (a) AC Electrical Characteristics (cont) Normal mode (cont) No. Parameter Symbol Min Max Unit 28 $%(1 high to address valid tAHAI 40 — ns 28A Address valid to ABEN High tAVEH 25 — ns 29 5($'< low to data in tRLDI — 150 ns 30 '6 high to data invalid tDHD 0 — ns 31 '6 high to 5($'< high tDHRE 0 160 ns 32 Data out valid to '6 low tDVDL 0 — ns 33 '6 high to data invalid tSHDI 40 — ns 34 Clock high to address valid tCHAV — 250 ns 35 Clock high to $%(1 low tCHEL — 140 ns 36 Clock high to '6 low tCHSL — 150 ns 37 Clock high to ',1 low tCHNL — 150 ns 38 Clock high to ',1 high tCHNH — 140 ns 39 ',1 low to '%(1 low tNLBL 20 — ns 40 '%(1 high to ',1 high tBHNH 40 — ns 41 Clock high to S/8 PF valid tCHPV — 150 ns 42 Address valid to R/: low tAVWL 35 — ns 43 Clock high to R/: low tCHWL — 150 ns 44 R/: low to '6 low tWLSL 120 — ns 45 Clock low to '%(1 low tCLBL — 110 ns 46 Clock low to ',1 high impedance tCLNI — 150 ns 47 Clock low to '%(1 high impedance tCLBI — 140 ns 48 Clock low to , $6, '6 High tCLSH — 100 ns 49 RxD set-up time tRSUT 20 — ns 50 RxD hold time tRHT 20 — ns 51 RxC cycle time tRCYC 0.2 125 µs 52 TxC low to TXD valid tTLTV — 100 ns 55 TxC cycle time tTCYC 0.2 125 µs 56 RESET pulse width tRST 24 — clocks 57 '6 high to ,$&. high tDHIH 0 — ns 58 Clock high to ,54 low tCHRL — 140 ns 59 Clock change to ,54 high tCCRH — 150 ns 2.0, 05/00, page 104 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Table 5-4 (b) AC Electrical Characteristics (VCC = 5 V ± 5%, VSS = 0 V, Ta = 0°C to +70°C, unless otherwise noted) Double frequency mode No. Parameter Symbol Min Max Unit Operating frequency f 4 12.5 MHz 1 Clock cycle time tCYC 80 250 ns 2 Clock width low tCL 35 125 ns 3 Clock width high tCH 35 125 ns 4 Clock fall time tCf — 5 ns 5 Clock rise time tCr — 5 ns 6 Asynchronous input set-up time tASI 25 — ns 7 Set-up time from $6 tASS 0 — ns 8 Clock low to 5($'< low tCLR — 120 ns 9 Clock high to ',1, '%(1, A/D valid tCHD — 250 ns 10 Clock low to '%(1 low tCLD — 120 ns 11 5($'< low to '6 high tRLD 1.0 — clocks 12 $6 high to address invalid tAHI 0 — ns 13 '6 high to ',1 high impedance tDHDH — 140 ns 14 '6 high to '%(1 high impedance tDHBH — 140 ns 15 '6 high to data invalid tDHDI 0 — ns 16 '6 high to 5($'< high impedance tDHRH — 140 ns 16A 5($'< high to high impedance tRHHI 10 — ns 17 Clock high to ',1 low tCHDL — 140 ns 18 Data in to '%(1 low tDIBL 25 — ns 19 Clock low to '%(1 high tCLBH — 100 ns 20 Clock high to ',1 high tCHDH — 140 ns 21 5($'< low to A/D invalid tRLAI 2.0 — clocks 22 Clock high to %5(4 low tCHBL — 150 ns 23 %$&. set up time from CLK tBSC 30 — ns 24 %$&. low to $,1 low tBLAL 5.0 7.0 clocks 25 Clock high to %5(4#high tCHBH — 150 ns 26 Clock high to $,1 high tCHAH — 90 ns 27 Address valid to $6 low tAVAL 40 — ns 28 $%(1 high to address invalid tAHAI 40 — ns 28A Address valid to $%(1 high tAVEH 25 — ns Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 105 of 168 Table 5-4 (b) AC Electrical Characteristics (cont) Double frequency mode (cont) No. Parameter Symbol Min Max Unit 29 5($'< low to data in tRLDI — 150 ns 30 '6 high to data invalid tDHD 0 — ns 31 '6 high to 5($'< high tDHRE 0 160 ns 32 Data out valid to '6 low tDVDL 0 — ns 33 '6 high to data invalid tSHDI 40 — ns 34 Clock high to address valid tCHAV — 250 ns 35 Clock high to $%(1 low tCHEL — 140 ns 36 Clock high to '6 low tCHSL — 150 ns 37 Clock high to ',1 low tCHNL — 150 ns 38 Clock high to ',1 high tCHNH — 140 ns 39 ',1 low to '%(1 low tNLBL 20 — ns 40 '%(1 high to ',1 high tBHNH 40 — ns 41 Clock high to S/8 PF valid tCHPV — 180 ns 42 Address valid to R/: low tAVWL 30 — ns 43 Clock high to R/: low tCHWL — 150 ns 44 R/: low to '6 low tWLSL 120 — ns 45 Clock low to '%(1 low tCLBL — 110 ns 46 Clock low to ',1 high impedance tCLNI — 150 ns 47 Clock low to '%(1 high impedance tCLBI — 140 ns 48 Clock low to $6 '6 high tCLSH — 100 ns 49 RxD set up time tRSUT 20 — ns 50 RxD hold time tRHT 20 — ns 51 RxC cycle time tRCYC 0.2 125 µs 52 TxC low to TxD valid tTLTV — 100 ns 55 TxC cycle time tTCYC 0.2 125 µs 56 RESET pulse width tRST 48 — clocks 57 '6 high to ,$&. high tDHIH 0 — ns 58 Clock high to ,54 low tCHRL — 140 ns 59 Clock change to ,54 high tCCRH — 150 ns 2.0, 05/00, page 106 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 5.4 Timing Diagrams t cyc t CL 1 t CH 2 3 2.0 V CLK 0.8 V t cr t cf 5 4 Figure 5-1 Input Clock Waveform t RST 56 RES Figure 5-2 Reset Input Timing Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 107 of 168 Figure 5-3 Host CPU Read Cycle 2.0, 05/00, page 108 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 READY (O) A 8 /D 0 – A 23 /D 15 (O) DBEN (O) DIN (O) LDS (I) HDS (I) R/W (I) CS (I) AS (I) A 1 –A 3 (I) CLK 6 6 t ASI 6 t ASI 6 t ASI t ASI 2 (I): Input (O): Output 7 t ASS 1 t ASI 6 t ASI 6 3 4 9 t CHD 9 t CHD 9 t CHD 5 6 t CLD 10 7 8 t CLR 8 9 10 11 t RLD 11 12 12 t AHI 13 16A t RHHI 16 t DHRH 15 t DHDI 14 t DHBH 13 t DHDH 14 Figure 5-4 Host CPU Write Cycle Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 109 of 168 READY (O) A 8 /D 0 – A 23 /D15 (I) DBEN (O) DIN (O) LDS (I) HDS (I) R/W (I) CS (I) AS (I) A 1 –A 3 (I) CLK 6 6 t ASI 6 t ASI 6 t ASI t ASI 2 (I): Input (O): Output 7 t ASS 1 t ASI 6 t ASI 6 3 4 18 t DIBL 17 t CHDL 5 6 10 t CLD 7 8 10 19 t CLBH 9 11 t RLD 21 t RLAI 20 t CHDH 11 12 16A t DHRH 14 t DHBH 13 t DHDH t RHHI 14 16 13 26 25 14 HD64541 cycle 13 12 11 10 9 8 7 24 6 5 22 23 4 3 AIN (O) BACK (I) BREQ (O) CLK (I) Bus cycle MPU cycle 2 1 Figure 5-5 Bus Arbitration Timing 2.0, 05/00, page 110 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Figure 5-6 DMA Read/Write Timing Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 111 of 168 1 –A 7 (O) PF (O) S/U (O) READY (I) DBEN (O) DIN (O) AIN (O) R/W (O) LDS (O) HDS (O) AS (O) ABEN (O) Input data A 8 /D0 –A 23 /D15 (O/O) A CLK t CHPV 41 t CHEL 35 34 1 37 t CHNL 36 t CHSL t AVAL 27 t AVEH 28A t CHAV 2 3 39 t NLBL t AHAI 28 4 t RLDI 29 Read cycle 5 6 7 t CHNH 38 30 t DHD 1 40 t BHNH t DHRE 31 8 42 t AVWL t CHWL 43 2 3 32 t DVDL 5 7 Write cycle 6 45 t CLBL 44 t WLSL 4 8 9 33 t CLSH t SHDI 48 10 47 t CLBI 46 t CLNI RXD (I) 49 t RSUT 50 t RHT 49 t RSUT 50 t RHT RXC (I) 51 t RCYC TXD (O) 52 t TLTV 52 t TLTV TXC (I) 55 t TCYC Figure 5-7 Transmit/Receive Timing 2.0, 05/00, page 112 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Figure 5-8 Interrupt Acknowledge Cycle Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 113 of 168 IRQ (O) IACK (I) READY (O) A 8 /D 0 – A 23 /D 15 (O) DBEN (O) DIN (O) LDS (I) HDS (I) R/W (I) CS (I) AS (I) A1 –A 3 (I) CLK (I) 6 t ASI 58 t CHRL 6 6 t ASI t ASI 2 3 8 t CLR 10 t CLD 4 5 6 11 t RLD 7 8 59 t CCRH 57 t DHIH 16 t DHRH 16A t RHHI 15 t DHDI 14 t DHBH 13 t DHDH Note: IRQ is driven inactive at the rising edge of when the interrupt source is in internal busy state, otherwise it is driven inactive at the falling edge of . 9 t CHD 9 t CHD 9 t CHD 1 (Note) 59 t CCRH 5.0 V 5.0 V C = 120 pF R L = 2.4 k Ω R = 12 k Ω 2.4 kΩ RL Test terminal Test terminal C Diode 1S2074 H R Output load circuit except IRQ Figure 5-9 Output Load Circuit 2.0, 05/00, page 114 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 120 pF IRQ load circuit Appendix A Command Details A.1 CPOL (Control Peripheral Output Pin Level) A.1.1 Format 0 7 6 5 4 3 2 1 0 0 1 1 1 1 1 1 0 — 1 2 — EN1 EN0 3 — PO1 PO0 A.1.2 ($10) Function CPOL sets the logic level of the two peripheral output pins. A.1.3 Command Usage The CPOL command is not valid during RSET command wait state. Using it will generate a command format error (CMSR = 010). This command is valid at all other times. A.1.4 Description The HD64541’s two peripheral output pins are driven from internal latches. CPOL loads new values into those latches. A new value (0/1), specified by PO, is loaded into the latch bit if the enable bit EN is set to 1. PO0 and EN0 operate on PO0 (pin No. 49), and PO1 and EN1 operate on PO1 (pin No. 50). The two pins are completely independent of each other and of the status of the LSI physical line. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 115 of 168 A.2 DDR1 (I-Frame Transmission 1) A.2.1 Format 0 7 6 5 4 3 2 1 0 0 0 1 0 0 0 0 0 1 — 2 — 3 FN ($20) P FN is the number of frames to be transmitted. A.2.2 Function DDR1 (and DDR2) initiates the transmission of a series of I-frames. DDR1 is not valid immediately after the posting of DESI status and before at least one execution of DDR2. A.2.3 Command Usage 1. This command is not valid if the HD64541 is offline in RSET command wait state. Using it will generate a command format error (CMSR = 010). 2. This command is not valid if the HD64541 is in transparent mode. Using it will generate a command format error (CMSR = 010). 3. This command is not valid with an FN which specifies the length of the output I-field buffer descriptor table. FN > NSI or FN = 0 will generate a command format error (CMSR = 010). 4. This command is not valid immediately after the posting of DESI status and before at least one execution of DDR2. This feature forces the driver software to recognize a logical link reset before resuming I-frame transmission. Attempting DDR1 immediately after DESI generate a cannot execute error (CMSR = 100). 5. This command is not valid if the logical link has not yet been established and will generate a cannot execute error (CMSR = 100). 2.0, 05/00, page 116 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 A.2.4 Description Initiates the transmission of a series of I-frames to the remote station over the logical link. FN specifies the number of I-frames in the series. The SII entry in the SIIT must be prepared prior to DDR execution. The SII contains buffer descriptors for the outbound I-fields. The P bit of the I-frame to be transmitted immediately following this command is set to the value of the P bit of this command, and the P bits from the second I-frame on are set to 0. A.3 DDR2 (I-Frame Transmission 2) A.3.1 Format 0 7 6 5 4 3 2 1 0 0 0 1 0 0 0 0 1 1 — 2 — 3 FN ($21) P FN indicates the number of frames to be transmitted. A.3.2 Function DDR2 (and DDR1) initiates the transmission of a series of I-frames. Unlike DDR1, DDR2 is also valid immediately after the posting of DESI status. DDR2 also initiates the transmission of frames in transparent mode. A.3.3 Command Usage 1. This command is not valid if the HD64541 is offline or during RSET command wait state. Using it will generate a command format error (CMSR = 010). 2. This command is not valid with an FN which specifies the length of the output I-field buffer descriptor table. FN > NSI or FN = 0 will generate a command format error (CMSR = 010). 3. This command is not valid if the logical link has not yet been established. Using it will generate a cannot execute error (CMSR = 100). Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 117 of 168 In transparent mode, before the current frame has finished being transmitted, the next command can initiate transmission of the following frame. In transparent mode, if commands are continuously issued before transmission has completed, confirm the completion of transmission by checking the status of TAIF, which corresponds to the final transmission of request frames. A.3.4 Description Initiates the transmission of a series of I-frames to the remote station over the logical link. FN specifies the number of I-frames in the series. The SII entry in the SIIT must have been prepared prior to DDR execution. The SII contains buffer descriptors for the outbound I-fields. A.4 DERC (Dump Statistical Information) A.4.1 Format 7 6 5 4 3 2 1 0 0 0 0 0 1 0 0 1 1 1 A23 Dump destination address (H) 2 Dump destination address (M) 3 Dump destination address (L) A.4.2 ($13) A0 Function DERC causes the HD64541 to write the contents of its internal logout table (LOGT), containing statistical counters, to external memory starting at the address specified in the command, and to clear the counters to zero. A.4.3 Command Usage The DERC command is not valid during RSET command wait state. Using it will generate a command format error (CMSR = 010). This command is valid at all other times. A.4.4 Description Writes the contents of the HD64541’s internal logout table (LOGT) to external memory starting at the address specified in the command and clears the counters to zero. 2.0, 05/00, page 118 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 A.4.5 Note Counter overflow beyond 255 is indistinguishable from an actual count of 255. A.5 DESR (Establish Link) A.5.1 Format 0 7 6 5 4 3 2 1 0 0 0 1 0 0 1 0 1 1 — 2 — 3 — A.5.2 ($25) Function DESR establishes the logical link. A.5.3 Command Usage 1. This command is not valid if the HD64541 is offline or in RSET command wait state. Using it will generate a command format error (CMSR = 010). 2. This command is not valid if the logical link has already been established. Using it will generate a cannot execute error (CMSR = 100). 3. This command is not valid if the HD64541 is in transparent mode. Using it will generate a command format error. A.5.4 Description Establishes the logical link by transmitting SABM/SABME command. DESI status is then reported. If the logical link cannot be established, DRLI status is reported. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 119 of 168 A.6 DESW (Remote Station Link Establish Wait) A.6.1 Format 0 7 6 5 4 3 2 1 0 0 0 1 0 1 0 0 1 1 — 2 — 3 — A.6.2 ($29) Function Places the HD64541 in link establish wait state (link established by remote station). A.6.3 Command Usage 1. This command is not valid if the HD64541 is not in data link release state. Using it will generate a cannot execute error. (CMSR=100) 2. This command is not valid if the HD64541 is offline or during RSET command wait state. Using it will generate a command format error (CMSR = 010). 3. This command is not valid if the HD64541 is in transparent mode. Using it will generate a command format error (CMSR = 010). A.6.4 Description 1. Places the HD64541 in data link establish wait state if data link has already been released. 2. Issue this command to establish the first link (after transition to on-line mode by the OMDS command) by receiving the SABM/SABME command from the remote station. If a SABM/SABME command sent from the remote station is received without this command being issued, the HD64541 will send a DM response. 2.0, 05/00, page 120 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 A.7 DRLR (Release Link) A.7.1 Format 0 7 6 5 4 3 2 1 0 0 0 1 0 0 1 1 0 1 — 2 — 3 — A.7.2 ($26) Function DRLR releases the logical link. A.7.3 Command Usage 1. This command is not valid if the HD64541 is offline or during RSET command wait state. Using it will generate a command format error (CMSR = 010). 2. This command is not valid if the HD64541 is in transparent mode. Using it will generate a command format error (CMSR = 010). 3. This command is not valid if the logical link has not been established. Using it will generate a cannot execute error (CMSR = 100). A.7.4 Description Releases the logical link by transmitting DISC command. After the link is released, DRLI status is reported. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 121 of 168 A.8 DSPT (Dump System Parameter Table (SYSPT)) A.8.1 Format 7 6 5 4 3 2 1 0 0 0 0 0 1 0 0 1 0 1 A23 Dump destination address (H) 2 Dump destination address (M) 3 Dump destination address (L) A.8.2 ($12) A0 Function DSPT causes the HD64541 to write the contents of its internal system parameter table (SYSPT) to external memory starting at the address specified in the command. A.8.3 Command Usage The DSPT command is valid only when the HD64541 is offline. Using it otherwise will generate a command format error (CMSR = 010). A.8.4 Description Writes the contents of the HD64541’s internal system parameter table (SYSPT) to external memory starting at the address specified in the command. 2.0, 05/00, page 122 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 A.9 MPIS (Mask Information from Peripheral Input Pins) A.9.1 Format 7 6 5 4 3 2 1 0 0 0 0 0 1 0 0 0 1 1 A23 PI2 PI1 PI0 — — 2 ($11) — 3 When PIi = 1, PIi pin input is masked. A.9.2 Function MPIS controls whether level changes on the three peripheral input pins are reported to the external microprocessor via status PITL. A.9.3 Command Usage The MPIS command is not valid during RSET command wait state. Using it will generate a command format error (CMSR = 010). This command is valid at all other times. A.9.4 Description 1. Following a RSET command, all three peripheral input pins are masked off and no level changes are reported. 2. MPIS enables/disables reporting of level changes on the three pins independently. 3. If a level change occurs on a pin that has been masked off, the change is reported as soon as the pin is masked on. If multiple level transitions have occurred while the pin is masked off, only the last one is reported. 4. If the corresponding bit in the MPIS command was set to 1, level changes on that pin are not reported in the PITL status. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 123 of 168 A.10 MUDR (U and X Frame Transmission) A.10.1 Format 0 7 6 5 4 3 2 1 0 0 0 1 0 0 0 1 0 1 — 2 — 3 — A.10.2 ($22) Function MUDR initiates the transmission of a single UI, XID, or TEST frame. A.10.3 Command Usage 1. This command is not valid if the HD64541 is offline or in RSET command wait state. Using it will generate a command format error (CMSR = 010). 2. This command is not valid if the HD64541 is in transparent mode. Using it will generate a command format error (CMSR = 010). 3. This command is not valid when bit 2 of PMODE in SYSPT is set to 0, (U and X frame inhibit state). Using it will generate a command format error (CMSR = 010). A.10.4 Description Initiates the transmission of a single UI, XID, or TEST frame to the remote station over the logical link. The SUXI entry in the SUXIT must be prepared prior to MUDR execution. The SUXI contains buffer descriptors for the outbound I-field. Even if the transmission of a UI, XID, or TEST frame initiated by the previous MUDR commands is not finished, further MUDRs can be executed. If before transmission has completed more commands are continuously issued, confirm the completion of transmission by checking the status of TAIF, which corresponds to the final transmission of request frames. 2.0, 05/00, page 124 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 A.11 OMDS (Set Operating Mode) A.11.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 1 0 M2 M1 M0 — 1 2 — 3 — A.11.2 M0 State M2 M1 Mode 0 Online 0 0 Normal 1 Online 0 1 Local loopback 1 0 Auto echo 1 1 Auto echo with local loopback ($02) Function OMDS specifies three operating mode toggles: online/offline (M0), local loopback on/off (M1) and auto echo on/off (M2). A.11.3 Command Usage This command is not valid during RSET command wait state. Using it will generate a command format error (CMSR = 010). This command is valid at all other times. RSET command wait state immediately follows a hardware reset and is cleared by the execution of a RSET command from the external microprocessor. FSYC status is reported if flag sequence is received when this command changes an offline mode to an online mode. A.11.4 Description Bit M0: M0 controls whether the HD64541 is online or offline. • Online (= 0): Enables LAPB frame transmit and receive. If no outbound frames are ready for transmission, the HD64541 transmits flag sequence or frame specified in the procedure. • Offline (= 1): Disables LAPB frame receive. The HD64541 transmits continuous 1 bits. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 125 of 168 Bit M1: M1 controls local loopback (figure A-1). • Local loopback off (= 0): If auto echo is also off, establishes normal operation using TXD, RXD, TXC, and RXC pins. • Local loopback on (= 1): Causes transmit data to be internally looped back to receive data as though received over RXD. A clock must be provided on TXC as though normal operation were in effect. Both local loopback and auto echo may be on at the same time. Bit M2: M2 controls auto echo (figure A-1). • Auto echo off (= 0): If local loopback is also off, establishes normal operation using TXD, RXD, TXC, and RXC pins. (Auto echo is known as remote loopback.) • Auto echo on (= 1): Causes received data on RXD to be internally looped back out to TXD transmit data as though sent by the local station. A clock must be provided on TXC as though normal operation were in effect. Both local loopback and auto echo may be on at the same time. Normal operation Local loopback High TXD Transmitter Transmitter TXC TXC RXD Receiver TXD RXD Receiver RXC Auto echo RXC Local loopback with auto echo High TXD Transmitter TXD Transmitter TXC TXC RXD Receiver RXC RXD Receiver Figure A-1 Operation Modes 2.0, 05/00, page 126 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 RXC A.12 RESR (Reestablish Link) A.12.1 Format 0 7 6 5 4 3 2 1 0 0 0 1 0 1 0 1 0 1 — 2 — 3 — A.12.2 ($2A) Function Reestablishes link while communication is going on or in error recovery wait state. A.12.3 Command Usage 1. This command is not valid if the HD64541 is offline or during RSET command wait state. Using it will generate a command format error (CMSR = 010). 2. This command is not valid if the HD64541 is in transparent mode. Using it will generate a command format error (CMSR = 010). 3. This command is not valid if the logical link has not been established. Using it will generate a cannot execute error (CMSR = 100). A.12.4 Description Reestablishes link by transmitting SABM/SABME command. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 127 of 168 A.13 RETD (Resume Frame Transmission) A.13.1 Format 0 7 6 5 4 3 2 1 0 0 0 1 0 0 1 0 0 1 — 2 — 3 — A.13.2 ($24) Function Resumes I-, UI, XID, and TEST frame transmission. A.13.3 Command Usage The RETD command is not valid if the HD64541 is offline or during RSET command wait state. Using it will generate a command format error (CMSR = 010). A.13.4 Description Reverses the effect of a previously executed SUTD command and allows the resumption of I-, UI, XID, and TEST frame transmission. 2.0, 05/00, page 128 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 A.14 RSBY (Release Local Station from Busy State) A.14.1 Format 0 7 6 5 4 3 2 1 0 0 0 1 0 1 0 0 0 1 — 2 — 3 — A.14.2 ($28) Function RSBY releases the logical link from the busy state set by a previously executed SSBY command. A.14.3 Command Usage 1. This command is not valid if the HD64541 is offline or during RSET command wait state. Using it will generate a command format error (CMSR = 010). 2. This command is not valid if the HD64541 is in transparent mode. Using it will generate a command format error (CMSR = 010). 3. RSBY is allowed even in HD64541 internal busy state. 4. This command is not valid for a logical link that cannot change from busy to non-busy. Using it will generate a cannot execute error (CMSR = 100). A.14.4 Description The logical link exits the busy state previously set by SSBY. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 129 of 168 A.15 RSET (Reset) A.15.1 Format 7 6 5 4 3 2 1 0 0 0 0 1 0 1 0 0 0 1 A23 System parameter table start address (H) 2 System parameter table start address (M) 3 System parameter table start address (L) A.15.2 ($01) A0 Function RSET resets the HD64541’s internal status and causes the HD64541 to read new system operating parameters from the system parameter table (SYSPT) whose address is specified in the RSET command. A.15.3 Command Usage This command is valid only when the HD64541 is offline. A.15.4 Description 1. Initializes HD64541 internal status. 2. Loads new system parameters from the specified SYSPT. 3. RSET command wait state immediately follows a hardware reset and is cleared by the execution of a RSET command from the external microprocessor. A.15.5 Notes 1. A bus exception during SYSPT parameter fetch causes the bus cycle to terminate abnormally and generates an interrupt with CMSR = 010. If the interrupt vector cannot be properly fetched, vector 0FH is used. 2. The HD64541 does not check the validity of parameters loaded from the SYSPT. 2.0, 05/00, page 130 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 A.16 SSBY (Set Local Station to Busy State) A.16.1 Format 0 7 6 5 4 3 2 1 0 0 0 1 0 0 1 1 1 1 — 2 — 3 — A.16.2 ($27) Function SSBY sets the logical link to busy. A.16.3 Command Usage 1. This command is not valid if the HD64541 is offline or during RSET command wait state. Using it will generate a command format error (CMSR = 010). 2. This command is not valid if the HD64541 is in transparent mode. Using it will generate a command format error (CMSR = 010). 3. This command is not valid for a logical link that cannot change from non-busy to busy. Using it will generate a cannot execute error (CMSR = 100). 4. SSBY is allowed even in HD64541 internal busy state. 5. The busy state set by SSBY has no affect on logical link reestablish and release procedures. A.16.4 Description Logical link busy set by SSBY may be cancelled by RSBY command or releasing logical link. Busy may be also cancelled by a transition to offline. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 131 of 168 A.17 STAC (Set Area Code) A.17.1 Format 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 0 AC0 2 0 0 0 0 0 0 AC1 3 0 0 0 0 0 0 AC2 ($00) The two bits in each of the three area code fields (AC0–AC2) correspond to the S/8 and PF pins used in the HD64541 memory management scheme. Bit 0 maps to the supervisor/user pin S/8 and bit 1 maps to the program fetch (PF) pin. Note that the program fetch (PF) pin is not to be confused with the LAPB protocol poll/final (P/F) bit. A.17.2 Function STAC specifies the area code (AC) values to be used by the HD64541 during DMA operations. A.17.3 Command Usage This command is always valid. A.17.4 Description Every address during a DMA transfer operation is accompanied by an area code specification (S/8 and PF pins) that allows the targeted memory to either allow or reject the access. The HD64541 separates its memory resident control tables into three access classes, one associated with each of the three AC fields in the STAC command. When accessing a particular table in memory, its associated ACn determines the value of the S/8 and PF pins sent out on the bus. Table A-1 shows the three access classes and the control tables they encompass. Table A-1 Access to Control Tables AC Read Access Write Access AC0 SYSPT, REJIT SYSDT, LOGT, REJIT AC1 SIIT, ESII, RBIT, SUXIT SIIT, SUXIT, RBIT AC2 SDB RDB 2.0, 05/00, page 132 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 A.17.5 Notes 1. After a hardware reset, ACn values are unpredictable. 2. A software reset (RSET) has no effect on ACn values. 3. STAC must follow a hardware reset and may precede RSET. A.18 SUTD (Suspend Frame Transmission) A.18.1 Format 0 7 6 5 4 3 2 1 0 0 0 1 0 0 0 1 1 1 — 2 — 3 — A.18.2 ($23) Function Temporarily suspends I-, UI, XID, and TEST frame transmission. A.18.3 Command Usage 1. The SUTD command is not valid if the HD64541 is offline or during RSET command wait state. Using it will generate a command format error (CMSR = 010). 2. When the operation mode is switched to off-line mode from on-line mode, suspended state will be cleared. 3. If SUTD is issued in this suspended state, command operation will be terminated normally while suspended state remains. A.18.4 Description I-, UI, XID, or TEST frame transmission initiated by DDR1, DDR2, and MUDR commands is suspended until the resume transmission command RETD is executed. A frame whose transmission is already in progress when SUTD is executed is allowed to continue to completion. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 133 of 168 Appendix B Status Details B.1 ACIF (Verify I-Frame) B.1.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 1 1 1 — 2 ASIIN 3 — B.1.2 ($03) Reporting Function 1. Indicates that a transmitted I-frame has been acknowledged by the remote station. 2. ASIIN identifies the SII buffer descriptor holding the acknowledged frame. B.2 DESI (Establish Link) B.2.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 1 1 1 — 2 — 3 — B.2.2 ($01) Reporting Function 1. The logical link has been established or reestablished by the remote station. The HD64541 received SABM/SABME and responded with UA. 2. The logical link has been established or reestablished by the local station. The HD64541 sent SABM/SABME by DESR or RESR command and received UA. 3. The HD64541 was unable to successfully complete the transmission of an I-frame initiated by DDR1 or DDR2 earlier. 2.0, 05/00, page 134 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 B.3 DRLI (Release Link) B.3.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 1 0 1 — 2 — 3 — B.3.2 ($02) Reporting Function 1. The logical link has been released on the remote station’s initiative. 2. The logical link establishment from the local station did not complete successfully by receiving DM frame from the remote station. B.4 FREC (Receive Frames) B.4.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 0 1 0 1 0 1 — 2 RBIN 3 — B.4.2 ($0A) Reporting Function A frame containing an I-field has been correctly received and the I-field has been stored in the buffer whose descriptor is identified by RBIN. Information regarding the frame type is stored in the corresponding RBI. FREC is reported once per frame and not once per buffer. If the frame’s I-field spilled across two or more buffers, FREC is reported only once. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 135 of 168 B.5 FSYC (Flag Synchronization ) B.5.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 1 0 1 0 0 1 — 2 — 3 — B.5.2 ($14) Reporting Function 1. The HD64541 received a flag sequence from the remote station during on-line mode that had been set by OMDS command from the external microprocessor. 2. The HD64541 received a flag sequence from the remote station after timer T3 runout had occurred. B.6 IDET (Idle Detection) B.6.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 1 0 0 0 0 1 — 2 — 3 — B.6.2 ($10) Reporting Function 1. T3 time has elapsed since the detection of an idle pattern. 2. If bit 3 of PMODE in SYSPT is set to 0, IDET will be sent to the external microprocessor immediately following the detection of an idle pattern. 2.0, 05/00, page 136 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 IDET status reporting condition • Receive continuous 1s for a period of at least 15 bit times when line rate is up to 1.5 Mbps. • Receive continuous 1s for a period of at least 18 bit times when line rate is more than 1.5 Mbps. B.7 LRST (Reset Link) B.7 1 Format 0 7 6 5 4 3 2 1 0 0 0 0 1 0 1 1 0 1 — 2 — 3 — B.7.2 ($16) Reporting Function 1. The HD64541 issued a SABM/SABME command to initiate a link reset. 2. Issuing this status prevents the HD64541 from execute commands such as data transmission before UA response from the remote station is received. 3. When the HD64541 receives a UA response from the remote station, it sends DESI (establish link) status to the external microprocessor and is placed in link establish state. 4. This status is issued when a SABM/SABME command is transmitted in any of the following cases: a. FRMR is received b. T1 runout occurs N2 times (in X.25 and X.75 modes) c. Unexpected supervisory frame with F = 1 is received (in X.25 mode) d. Unexpected UA or DM response is received (in X.25 mode) 5. The HD64541 does not issue this status if it transmits a SABM/SABME command on the Reestablish Link (RESR) command from the external microprocessor. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 137 of 168 B.8 PITL (Peripheral Input Pin Level) B.8.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 0 0 1 1 0 — 1 2 0 0 0 0 0 PI2 PI1 PI0 3 0 0 0 0 0 PT2 PT1 PT0 B.8.2 ($06) Reporting Function 1. A level transition has occurred on any one or more of the three peripheral input pins PI0, PI1, or PI2 and the pin(s) are not currently masked by the MPIS command. If they are masked, the transition report is held pending until they are unmasked. If more than one transition occurs on the same pin while masked, only the last transition is reported when it is finally unmasked. 2. Bits PT0, PT1, and PT2 are set to 1 when reporting a transition on the associated pin. 3. Bits PI0, PI1, and PI2 are set to the new level after the transition. See figure B-1. 2.0, 05/00, page 138 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Command RSET PI0 pin 1 0 PI1 pin 1 0 PI2 pin 1 0 MPIS MPIS MPIS 1 PI0 mask 0 1 PI1 mask 0 1 PI2 mask 0 1 PITL status 2 3 4 5 PI2 PI1 PI0 PT2 PT1 PT0 1 1 0 0 0 0 0 2 1 1 0 0 1 0 3 1 1 1 0 0 1 4 1 1 0 0 0 1 5 1 0 1 0 1 1 Figure B-1 Masking Peripheral Input Pins Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 139 of 168 B.9 RRBY (Remote Station Busy Release) B.9.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 0 0 1 0 1 1 — 2 — 3 — B.9.2 ($05) Reporting Function The logical link has exited remote station busy by receiving RR from the remote station. B.10 SRBY (Remote Station Busy) B.10.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 0 0 1 0 0 1 — 2 — 3 — B.10.2 ($04) Reporting Function The logical link has entered remote station busy state by receiving RNR from the remote station. 2.0, 05/00, page 140 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 B.11 SRC1 (System Recovery Request 1) B.11.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 1 0 0 0 1 1 — 2 — 3 — B.11.2 ($11) Reporting Function • Receiving an FRMR-response has caused the HD64541 to be placed in error recovery wait state. • The I-field of the received FRMR response is sent to the REJIT table. B.12 SRC2 (System Recovery Request 2) B.12.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 1 0 0 1 0 1 — 2 — 3 — B.12.2 ($12) Reporting Function Though the local station retransmitted frames N2 times, no response was received from the remote station and timer T1 runout occurred in each retransmission. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 141 of 168 B.13 TAIF (Terminate Frame Transmission) B.13.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 0 0 1 1 1 1 — 2 SIIN 3 — B.13.2 ($07) Reporting Function TAIF status is valid only in transparent mode. The transmission of a frame initiated by the DDR2 command has completed. SIIN identifies the SII buffer descriptor of the frame transmitted. B.14 TAUF (Terminate U and X Frame Transmission) B.14.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 0 1 0 0 1 1 — 2 SUXIN 3 — B.14.2 ($09) Reporting Function The transmission of XID, UI or TEST frames initiated by the MUDR command has completed. SUXIN identifies the SUXI buffer descriptor of the frame transmitted. 2.0, 05/00, page 142 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 B.15 YRCV (Remote Station System Recovery Request) B.15.1 Format 0 7 6 5 4 3 2 1 0 0 0 0 1 0 0 1 1 1 — 2 — 3 — B.15.2 ($13) Reporting Function 1. Because an unrecoverable retransmitted frame had been received from the remote station, FRMR response was sent and the HD64541 is placed in the frame reject state. 2. The I-field of the transmitted FRMR response is stored in the REJIT table. Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 143 of 168 Appendix C Link Layer Protocol Sequence Diagrams Typical examples of layer 2 protocol sequence diagrams are shown in this appendix. Refer to the state transition table in CCITT recommendation T.90, X.75, and X.25 (’88) in other cases. Frame type Transmission sequence number N(S) Receive sequence number N(R) Command Local station HD64541 Host MPU Remote station I-frame transmission (DDR1 or DDR2), FN = 1 Command issued Report by CMSR I, O, O, P Command normal end (CMSR2–CMSR0 = 000) P: P: F: F: P bit = 1 P bit = 0 F bit = 1 F bit = 0 Status report Verify I-frame (ACIF) Status RR, 1, F Receive sequence number N(R) Figure C-1 Explanation of Figures 2.0, 05/00, page 144 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Local station Host MPU Remote station HD64541 Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status (DESI) Release link command DISC, P (DRLR) Command normal end (CMSR2–CMSR0 = 000) UA, F Release link status (DRLI) Figure C-2 Link Establishment and Link Release from Local Station Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 145 of 168 Local station Host MPU Remote station HD64541 Remote station link establish wait command (DESW) Command normal end (CMSR2–CMSR0 = 000) SABM, P Establish link status (DESI) UA, F DISC, P Release link status (DRLI) UA, F DM, F SABM, P X.25 mode UA, F Establish link status (DESI) Figure C-3 Link Establishment and Link Release from Remote Station 2.0, 05/00, page 146 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Local station Host MPU Remote station HD64541 Establish link command SABM, P (DESR) T1 SABM, P Command normal end (CMSR2–CMSR0 = 000) SABM, P Timer T1 runout at N2 retransmission T1 System recovery request 2 status (SRC2) Figure C-4 Timer T1 runout during SABM Command Transmission Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 147 of 168 Local station Host MPU Remote station HD64541 Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status (DESI) Release link command DISC, P (DRLR) T1 DISC, P Command normal end (CMSR2–CMSR0 = 000) DISC, P Timer T1 runout at N2 retransmission T1 System recovery request 2 status (SRC2) Figure C-5 Timer T1 runout during DISC Command Transmission 2.0, 05/00, page 148 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Local station Host MPU Remote station HD64541 Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status I-frame transmission 2 command (DDR2) FN = 1 (DESI) I, 0, 0, P T1 Command normal end (CMSR2–CMSR0 = 000) RR, P RR, P Timer T1 runout at N2 T1 retransmission SABM, P System recovery request 2 status (SRC2) T1 Reset link status (LRST) SABM, P SABM, P Timer T1 runout at N2 T1 retransmission System recovery request 2 status (SRC2) Figure C-6 (a) Link Disconnection by HD64541 (X.25 and X.75 modes) Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 149 of 168 Local station HD64541 Host MPU Remote station Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status I-frame transmission 2 command (DDR2) FN = 1 (DESI) I, 0, 0, P T1 Command normal end (CMSR2–CMSR0 = 000) RR, P RR, P Timer T1 runout at N2 retransmission T1 SABM, P System recovery request 2 status (SRC2) Reset link status (LRST) RR, P DM, F (Release phase) Figure C-6 (b) Link Disconnection by HD64541 (T.90 mode) 2.0, 05/00, page 150 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Host MPU Local station HD64541 Remote station Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status I-frame transmission 2 command (DDR2) FN = 1 (DESI) I, 0, 0, P Command normal end (CMSR2–CMSR0 = 000) I-frame transmission 2 command (DDR2) FN = 2 RR, 1, F Verify I-frame status (ACIF) I, 1, 0, P I, 2, 0, P Command normal end (CMSR2–CMSR0 = 000) RR, 3, F Verify I-frame status (ACIF) Figure C-7 I-Frame Transmission Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 151 of 168 Local station HD64541 Host MPU Establish link command Remote station SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status I-frame transmission 2 command (DDR2) FN = 1 (DESI) I, 0, 0, P Command normal end (CMSR2–CMSR0 = 000) I, 0, 1, P Verify I-frame status (ACIF) Receive frames status (FREC) RR, 1, F Figure C-8 I-Frame Reception and Transmission 2.0, 05/00, page 152 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Local station HD64541 Host MPU Establish link command Remote station SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status I-frame transmission 2 command (DDR2) FN = 2 (DESI) I, 0, 0, P FCS error I, 1, 0, P Command normal end (CMSR2–CMSR0 = 000) REJ, 0, F I, 0, 0, P I, 1, 0, P (Retransmission) (Retransmission) RR, 2, F Verify I-frame status I-frame transmission 2 command (DDR2) FN = 1 (ACIF) I, 2, 0, P Command normal end (CMSR2–CMSR0 = 000) RR, 3, F Verify I-frame status (ACIF) Figure C-9 Recovery of I-Frame Transmit Error by REJ Reception Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 153 of 168 Local station HD64541 Host MPU Establish link command Remote station SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status I-frame transmission 2 command (DDR2) FN = 1 (DESI) I, 0, 0, P Command normal end (CMSR2–CMSR0 = 000) RR, 1, F (Unexpected frame) Reset link status (LRST) SABM, P UA, F Establish link status (DESI) Reset link status (LRST) UA, F (Unexpected frame) SABM, P UA, F Establish link status (DESI) Figure C-10 (a) Reception of Unexpected Frame (X.25 mode) 2.0, 05/00, page 154 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Local station HD64541 Host MPU Establish link command Remote station SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status I-frame transmission 2 command (DDR2) FN = 1 (DESI) I, 0, 0, P Command normal end (CMSR2–CMSR0 = 000) Reset link status (LRST) Establish link status (DESI) Remote station system recovery request (YRCV) RR, 1, F (Unexpected frame) FRMR, E SABM, P LA, F, (Unexpected frame) UA, F FRMR, E SABM, P Establish link status (DESI) UA, F Figure C-10 (b) Reception of Unexpected Frame (X.75 mode) Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 155 of 168 Local station HD64541 Host MPU Establish link command Remote station SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status I-frame transmission 2 command (DDR2) FN= 1 (DESI) I, 0, 0, P Command normal end (CMSR2–CMSR0 = 000) RR, I, F (Unexpected frame) (Count process error) UA, F (Unexpected frame) (Count process error) Figure C-10 (c) Reception of Unexpected Frame (T.90 mode) 2.0, 05/00, page 156 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Local station HD64541 Host MPU Remote station Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status I-frame transmission 2 command (DDR2) FN= 1 (DESI) I, 0, 0, P Command normal end (CMSR2–CMSR0 = 000) I, 0, 1, P Receive frame status RR, 1, F (FREC) Verify I-frame status (ACIF) N(S) V(R) I, 2, 1, P REJ, 1, F Receive frame status I, 1, 1, P (FREC) RR, 2, F Receive frame status I, 2, 1, P (FREC) RR, 3, F Figure C-11 I-Frame with N(S)≠ ≠V(R) Reception Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 157 of 168 Host MPU Local station HD64541 Remote station Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status I-frame transmission 2 command (DDR2) FN= 1 (DESI) I, 0, 0, P Command normal end (CMSR2–CMSR0 = 000) RR, 3, F (N(R) error) Remote station system recovery request status (YRCV) FRMR, F SABM, P Establish link status (DESI) Figure C-12 N(R) Error Frame Reception 2.0, 05/00, page 158 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 UA, F Local station Host MPU Remote station HD64541 Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status Set local station to busy state command (SSBY) (DESI) RNR, F Command normal end (CMSR2–CMSR0 = 000) RR, P RNR, F Release local station from busy state command (RSBY) RR, P Command normal end (CMSR2–CMSR0 = 000) RR, F Figure C-13 Local Station Busy Setting/Release Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 159 of 168 Host MPU Local station HD64541 Remote station Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status I-frame transmission 2 command (DDR2) FN = 1 (DESI) I, 0, 0, P Command normal end (CMSR2–CMSR0 = 000) RNR, 1, F Busy occurrence Remote station busy status (SRBY) Verify I-frame status T1 RR, P (ACIF) RNR, 1, F T1 RR, P Remote station busy release status RR, F Release busy (RRBY) Figure C-14 (a) Remote Station Busy Setting/Release (X.25 and X.75 modes) 2.0, 05/00, page 160 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Local station Host MPU Remote station HD64541 Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status I-frame transmission 2 command (DDR2) FN = 1 (DESI) I, 0, 0, P Command normal end (CMSR2–CMSR0 = 000) RNR, 1, F Busy occurrence Remote station busy status (SRBY) Verify I-frame status T1 RR, P (ACIF) RNR, 1, F T1 RR, P RNR, 1, F T1 System recovery request 2 (SRC2) RR, P DM, F Release busy Figure C-14 (b) Remote Station Busy Setting/Release (T.90 mode) Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 161 of 168 Host MPU Local station HD64541 Remote station Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status (DESI) I, 0, 0, P Receive frame status RR, 1, F (FREC) I, 1, 0, P Receive frame status K=7 (FREC) Receive frame status I, 2, 0, P ... ... (FREC) Receive frame status (FREC) I, 7, 0, P T2 I, 0, 0, P Invalid N(S) Receive frame status (FREC) RR, 1, F Figure C-15 (a) Reception of I-Frame with Invalid N(S) (X.25 mode) 2.0, 05/00, page 162 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Host MPU Local station HD64541 Remote station Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status (DESI) I, 0, 0, P Receive frame status RR, 1, F (FREC) I, 1, 0, P Receive frame status K=7 (FREC) Receive frame status ... ... (FREC) I, 2, 0, P I, 7, 0, P Receive frame status (FREC) Remote system recovery request status (YRCV) Establish link status (DESI) I, 0, 0, P Invalid N(S) FRMR, F SABM, P UA, F Figure C-15 (b) Reception of I-Frame with Invalid N(S) (X.75 mode) Powered by ICminer.com Electronic-Library Service CopyRight 2003 Rev. 2.0, 05/00, page 163 of 168 Host MPU Local station HD64541 Remote station Establish link command SABM, P (DESR) Command normal end (CMSR2–CMSR0 = 000) UA, F Establish link status (DESI) I, 0, 0, P Receive frame status RR, 1, F (FREC) I, 1, 0, P Receive frame status K=7 (FREC) Receive frame status I, 2, 0, P ... (FREC) I, 7, 0, P Receive frame status (FREC) I, 0, 0, P Invalid N(S) REJ, 0, F Receive frame status (FREC) I, 0, 0, P RR, 1, F Figure C-15 (c) Reception of I-Frame with Invalid N(S) (T.90 mode) 2.0, 05/00, page 164 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 Powered by ICminer.com Electronic-Library Service CopyRight 2003 RSET Reset DRLR DESR RETD SUTD MUDR DDR2 DDR1 DERC DSPT Reestablish link RESR Set local station SSBY to busy state Release local station RSBY from busy state Remote station DESW link establish wait Release link Establish link Dump system parameter table Dump statistical information I-frame transmission 1 I-frame transmission 2 U and X frame transmission Suspend frame transmission Resume frame transmission Control peripheral CPOL output pin level Mask information from MPIS peripheral input pins Set operating mode OMDS STAC Set area code Name Protocol (2A) (29) (28) (27) (26) (25) (24) (23) (22) (21) (20) (13) (12) Dump address Dump address P P P PP 2 1 0 Starting address of system parameter table A C 1 (11) MMM 2 1 0 A C 0 #2 (10) #1 Format Command parameter E E 1 0 (02) (01) (00) #0 (HEX) FN FN #3 Format Format Format P P Format 1 0 A C 2 Format Format Format Format Unexecutable Unexecutable *1 Format Unexecutable Format Format Format Transparent mode Operating mode FN=0, >NSI Off-line On-line FN= Unexe- UnexeFormat Format cutable cutable Command LAPB mode Reset com- Operating mode U, X After Before Before mand frame FN=0, >NSI SSBY SSBY DDR2 waiting Off-line On-line inhibited FN= Note: 1. A cannot execute error may sometimes occur depending on the state of the link at the time command is issued. 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 No. Type Structure control Maintenance & peripheral control Transmission control Mnemonic Transparent Table D-1 Link Layer Controller Command Error & Status List Appendix D Link Layer Controller Command Error and Status List Rev. 2.0, 05/00, page 165 of 168 2.0, 05/00, page 166 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 ACIF SRBY Verify I-frame Remote 4 station busy Remote station 5 busy release IDET Idle detection 15 Reset link tion LRST 14 Flag synchroniza- FSYC 13 tem recovery request Remote station sys- YRCV System recovery SRC1 11 request 1 System recovery SRC2 12 request 2 10 9 FREC TAUF TAIF PITL Peripheral input 6 pin level Terminate frame 7 transmission Terminate U and X 8 frame transmission Receive frames 3 2 RRBY DRLI Release link 1 DESI Name Establish link No. Mnemonic Protocol Status (16) (14) (13) (12) (11) (10) (0A) (09) (07) (06) (05) (04) (03) (02) (01) #0 (HEX) #1 I I I 2 1 0 RBIN SUXIN SIIN ASIIN #2 Format Status parameter Table D-1 Link Layer Controller Command Error & Status List (cont) Transparent #3 T TT 2 1 0 Appendix E Package Dimensions Package Dimensions Unit: mm 25.15 +0.12 –0.13 24.20 60 44 43 68 1 27 0.75 0.20 M 26 1.94 1.27 *0.42 ± 0.10 0.38 ± 0.08 23.12 ± 0.50 *Dimension including the plating thickness Base material dimension Powered by ICminer.com Electronic-Library Service CopyRight 2003 0.90 10 2.55 ± 0.15 9 4.40 ± 0.20 25.15 +0.12 –0.13 61 23.12 ± 0.50 0.10 Hitachi Code JEDEC EIAJ Mass (reference value) CP-68 Conforms Conforms 4.2 g Rev. 2.0, 05/00, page 167 of 168 14.0 ± 0.2 Unit: mm 12 60 41 40 80 21 0.5 14.0 ± 0.2 61 0.10 *Dimension including the plating thickness Base material dimension 0.10 ± 0.10 1.25 1.00 0.10 M 2.0, 05/00, page 168 of 168 Powered Rev. by ICminer.com Electronic-Library Service CopyRight 2003 *0.17 ± 0.05 0.15 ± 0.04 20 1.20 Max 1 *0.22 ± 0.05 0.20 ± 0.04 1.0 0° – 8° 0.5 ± 0.1 Hitachi Code JEDEC EIAJ Mass (reference value) TFP-80C — Conforms 0.4 g HD64541 User’s Manual Powered by Publication Date: 1st Edition, March 1991 2nd Edition, May 2000 Published by: Electronic Devices Sales & Marketing Group Semiconductor & Integrated Circuits Hitachi, Ltd. Edited by: Technical Documentation Group Hitachi Kodaira Semiconductor Co., Ltd. Copyright © Hitachi, Ltd.,CopyRight 1991. All rights reserved. Printed in Japan. ICminer.com Electronic-Library Service 2003