![Intel IXP45X Скачать руководство пользователя страница 19](http://html1.mh-extra.com/html/intel/ixp45x/ixp45x_developers-manual_2073092019.webp)
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
August 2006
Developer’s Manual
Order Number: 306262-004US
19
Contents—Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
13.0 HSS Coprocessor .................................................................................................... 723
13.1.1 High-Speed Serial Interface Receive Operation......................................... 724
13.1.2 High-Speed Serial Interface Transmit Operation ....................................... 725
13.2 Feature List .................................................................................................... 725
13.3 Theory of Operation......................................................................................... 726
13.3.1.2 Lookup Tables ........................................................................ 727
13.3.2 Endianness.......................................................................................... 730
13.3.3 Programmable Frame Pulse Offset and Frame Synchronization ................... 730
13.3.4 Underflow/Overflow/Unexpected Frame Pulse........................................... 732
13.3.5 56K Mode............................................................................................ 733
13.3.6 Frameless Data Protocol Support ............................................................ 733
13.3.7 Loopback ............................................................................................ 733
13.4.1 HSS Clock and Jitter ............................................................................. 734
13.4.2 Overview of HSS Clock Configuration ...................................................... 735
13.5.1 T1 ...................................................................................................... 736
13.5.2 E1...................................................................................................... 738
13.5.3 GCI .................................................................................................... 740
13.5.3.1 Line-Card Mode ...................................................................... 740
13.5.3.2 Termination Mode ................................................................... 741
13.5.4.1 2.048-Mbps Backplane ............................................................ 743
13.5.4.2 4.096-Mbps Backplane ............................................................ 744
13.5.4.3 8.192-Mbps Backplane ............................................................ 746
14.0 Universal Asynchronous Receiver-Transmitter (UART) .......................................... 749
14.1 Overview ....................................................................................................... 749
14.2 Feature List .................................................................................................... 750
14.3 Block Diagram ................................................................................................ 751
14.4 Theory of Operation......................................................................................... 752
14.4.1 Setting the Baud Rate........................................................................... 753
14.4.2 Setting Data Bits/Stop Bits/Parity ........................................................... 753
14.4.3 Using the Modem Control Signals ........................................................... 756
14.4.4 UART Interrupts ................................................................................... 757
14.4.5 Transmitting and Receiving UART Data.................................................... 760
14.5.1 Receive Buffer Register ......................................................................... 762
14.5.2 Transmit Holding Register ..................................................................... 763
14.5.3 Divisor Latch Low Register..................................................................... 763
14.5.4 Divisor Latch High Register .................................................................... 764
14.5.5 Interrupt Enable Register ...................................................................... 764
14.5.6 Interrupt Identification Register ............................................................. 765
14.5.7 FIFO Control Register............................................................................ 767
14.5.8 Line Control Register ............................................................................ 768
14.5.9 Modem Control Register ........................................................................ 770
14.5.10Line Status Register.............................................................................. 771
14.5.11Modem Status Register ......................................................................... 772
14.5.12Scratch-Pad Register ............................................................................ 773
14.5.13Infrared Selection Register .................................................................... 774