SPRUGR9H November   2010  – April 2015 66AK2E05 , 66AK2H06 , 66AK2H12 , 66AK2H14 , 66AK2L06 , AM5K2E02 , AM5K2E04 , SM320C6678-HIREL , TMS320C6652 , TMS320C6654 , TMS320C6655 , TMS320C6657 , TMS320C6670 , TMS320C6671 , TMS320C6672 , TMS320C6674 , TMS320C6678

 

  1.   Preface
    1.     About This Manual
    2.     Trademarks
    3.     Notational Conventions
    4.     Related Documentation from Texas Instruments
  2. 1Introduction
    1. 1.1  Terminology Used in This Document
    2. 1.2  KeyStone I Features
    3. 1.3  KeyStone I Functional Block Diagram
    4. 1.4  KeyStone II Changes to QMSS
    5. 1.5  KeyStone II QMSS Modes of Use
      1. 1.5.1 Shared Mode
      2. 1.5.2 Split Mode
    6. 1.6  Overview
    7. 1.7  Queue Manager
    8. 1.8  Packet DMA (PKTDMA)
    9. 1.9  Navigator Cloud
    10. 1.10 Virtualization
    11. 1.11 ARM-DSP Shared Use
    12. 1.12 PDSP Firmware
  3. 2Operational Concepts
    1. 2.1 Packets
    2. 2.2 Queues
      1. 2.2.1 Packet Queuing
      2. 2.2.2 Packet De-queuing
      3. 2.2.3 Queue Proxy
    3. 2.3 Queue Types
      1. 2.3.1 Transmit Queues
      2. 2.3.2 Transmit Completion Queues
      3. 2.3.3 Receive Queues
      4. 2.3.4 Free Descriptor Queues (FDQ)
        1. 2.3.4.1 Host Packet Free Descriptors
        2. 2.3.4.2 Monolithic Free Descriptors
      5. 2.3.5 Queue Pend Queues
    4. 2.4 Descriptors
      1. 2.4.1 Host Packet
      2. 2.4.2 Host Buffer
      3. 2.4.3 Monolithic Packet
    5. 2.5 Packet DMA
      1. 2.5.1 Channels
      2. 2.5.2 RX Flows
    6. 2.6 Packet Transmission Overview
    7. 2.7 Packet Reception Overview
    8. 2.8 ARM Endianess
  4. 3Descriptor Layouts
    1. 3.1 Host Packet Descriptor
    2. 3.2 Host Buffer Descriptor
    3. 3.3 Monolithic Descriptor
  5. 4Registers
    1. 4.1 Queue Manager
      1. 4.1.1 Queue Configuration Region
        1. 4.1.1.1 Revision Register (0x00000000)
        2. 4.1.1.2 Queue Diversion Register (0x00000008)
        3. 4.1.1.3 Linking RAM Region 0 Base Address Register (0x0000000C)
        4. 4.1.1.4 Linking RAM Region 0 Size Register (0x00000010)
        5. 4.1.1.5 Linking RAM Region 1 Base Address Register (0x00000014)
        6. 4.1.1.6 Free Descriptor/Buffer Starvation Count Register N (0x00000020 + N×4)
      2. 4.1.2 Queue Status RAM
      3. 4.1.3 Descriptor Memory Setup Region
        1. 4.1.3.1 Memory Region R Base Address Register (0x00000000 + 16×R)
        2. 4.1.3.2 Memory Region R Start Index Register (0x00000004 + 16×R)
        3. 4.1.3.3 Memory Region R Descriptor Setup Register (0x00000008 + 16×R)
      4. 4.1.4 Queue Management/Queue Proxy Regions
        1. 4.1.4.1 Queue N Register A (0x00000000 + 16×N)
        2. 4.1.4.2 Queue N Register B (0x00000004 + 16×N)
        3. 4.1.4.3 Queue N Register C (0x00000008 + 16×N)
        4. 4.1.4.4 Queue N Register D (0x0000000C + 16×N)
      5. 4.1.5 Queue Peek Region
        1. 4.1.5.1 Queue N Status and Configuration Register A (0x00000000 + 16×N)
        2. 4.1.5.2 Queue N Status and Configuration Register B (0x00000004 + 16×N)
        3. 4.1.5.3 Queue N Status and Configuration Register C (0x00000008 + 16×N)
        4. 4.1.5.4 Queue N Status and Configuration Register D (0x0000000C + 16×N)
    2. 4.2 Packet DMA
      1. 4.2.1 Global Control Registers Region
        1. 4.2.1.1 Revision Register (0x00)
        2. 4.2.1.2 Performance Control Register (0x04)
        3. 4.2.1.3 Emulation Control Register (0x08)
        4. 4.2.1.4 Priority Control Register (0x0C)
        5. 4.2.1.5 QMn Base Address Register (0x10, 0x14, 0x18, 0x1c)
      2. 4.2.2 TX DMA Channel Configuration Region
        1. 4.2.2.1 TX Channel N Global Configuration Register A (0x000 + 32×N)
        2. 4.2.2.2 TX Channel N Global Configuration Register B (0x004 + 32×N)
      3. 4.2.3 RX DMA Channel Configuration Region
        1. 4.2.3.1 RX Channel N Global Configuration Register A (0x000 + 32×N)
      4. 4.2.4 RX DMA Flow Configuration Region
        1. 4.2.4.1 RX Flow N Configuration Register A (0x000 + 32×N)
        2. 4.2.4.2 RX Flow N Configuration Register B (0x004 + 32×N)
        3. 4.2.4.3 RX Flow N Configuration Register C (0x008 + 32×N)
        4. 4.2.4.4 RX Flow N Configuration Register D (0x00C + 32×N)
        5. 4.2.4.5 RX Flow N Configuration Register E (0x010 + 32×N)
        6. 4.2.4.6 RX Flow N Configuration Register F (0x014 + 32×N)
        7. 4.2.4.7 RX Flow N Configuration Register G (0x018 + 32×N)
        8. 4.2.4.8 RX Flow N Configuration Register H (0x01C + 32×N)
      5. 4.2.5 TX Scheduler Configuration Region
        1. 4.2.5.1 TX Channel N Scheduler Configuration Register (0x000 + 4×N)
    3. 4.3 QMSS PDSPs
      1. 4.3.1 Descriptor Accumulation Firmware
        1. 4.3.1.1 Command Buffer Interface
        2. 4.3.1.2 Global Timer Command Interface
        3. 4.3.1.3 Reclamation Queue Command Interface
        4. 4.3.1.4 Queue Diversion Command Interface
      2. 4.3.2 Quality of Service Firmware
        1. 4.3.2.1 QoS Algorithms
          1. 4.3.2.1.1 Modified Token Bucket Algorithm
        2. 4.3.2.2 Command Buffer Interface
        3. 4.3.2.3 QoS Firmware Commands
        4. 4.3.2.4 QoS Queue Record
        5. 4.3.2.5 QoS Cluster Record
        6. 4.3.2.6 RR-Mode QoS Cluster Record
        7. 4.3.2.7 SRIO Queue Monitoring
          1. 4.3.2.7.1 QoS SRIO Queue Monitoring Record
      3. 4.3.3 Open Event Machine Firmware
      4. 4.3.4 Interrupt Operation
        1. 4.3.4.1 Interrupt Handshaking
        2. 4.3.4.2 Interrupt Processing
        3. 4.3.4.3 Interrupt Generation
        4. 4.3.4.4 Stall Avoidance
      5. 4.3.5 QMSS PDSP Registers
        1. 4.3.5.1 Control Register (0x00000000)
        2. 4.3.5.2 Status Register (0x00000004)
        3. 4.3.5.3 Cycle Count Register (0x0000000C)
        4. 4.3.5.4 Stall Count Register (0x00000010)
    4. 4.4 QMSS Interrupt Distributor
      1. 4.4.1 INTD Register Region
        1. 4.4.1.1  Revision Register (0x00000000)
        2. 4.4.1.2  End Of Interrupt (EOI) Register (0x00000010)
        3. 4.4.1.3  Status Register 0 (0x00000200)
        4. 4.4.1.4  Status Register 1 (0x00000204)
        5. 4.4.1.5  Status Register 2 (0x00000208)
        6. 4.4.1.6  Status Register 3 (0x0000020c)
        7. 4.4.1.7  Status Register 4 (0x00000210)
        8. 4.4.1.8  Status Clear Register 0 (0x00000280)
        9. 4.4.1.9  Status Clear Register 1 (0x00000284)
        10. 4.4.1.10 Status Clear Register 4 (0x00000290)
        11. 4.4.1.11 Interrupt N Count Register (0x00000300 + 4xN)
  6. 5Mapping Information
    1. 5.1 Queue Maps
    2. 5.2 Interrupt Maps
      1. 5.2.1 KeyStone I TCI661x, C6670, C665x devices
      2. 5.2.2 KeyStone I TCI660x, C667x devices
      3. 5.2.3 KeyStone II devices
    3. 5.3 Memory Maps
      1. 5.3.1 QMSS Register Memory Map
      2. 5.3.2 KeyStone I PKTDMA Register Memory Map
      3. 5.3.3 KeyStone II PKTDMA Register Memory Map
    4. 5.4 Packet DMA Channel Map
  7. 6Programming Information
    1. 6.1 Programming Considerations
      1. 6.1.1 System Planning
      2. 6.1.2 Notification of Completed Work
    2. 6.2 Example Code
      1. 6.2.1 QMSS Initialization
      2. 6.2.2 PKTDMA Initialization
      3. 6.2.3 Normal Infrastructure DMA with Accumulation
      4. 6.2.4 Bypass Infrastructure notification with Accumulation
      5. 6.2.5 Channel Teardown
    3. 6.3 Programming Overrides
    4. 6.4 Programming Errors
    5. 6.5 Questions and Answers
  8. AExample Code Utility Functions
  9. BExample Code Types
  10. CExample Code Addresses
    1. C.1 KeyStone I Addresses:
    2. C.2 KeyStone II Addresses:
  11.   Revision History

2.6 Packet Transmission Overview

After a TX DMA channel has been initialized, it can begin to be used to transmit packets. Packet transmission involves the following steps:

  1. The host is made aware of one or more chunks of data in memory that need to be transmitted as a packet. This may involve directly sourcing data from the host or it may involve data that has been forwarded from another data source in the system.
  2. The host allocates a descriptor, usually from a TX completion queue, and fills in the descriptor fields and payload data.
  3. For host packet descriptors, the host allocates and populates host buffer descriptors as necessary to point to any remaining chunks of data that belong to this packet.
  4. The host writes the pointer to the packet descriptor into a specific memory mapped location inside the queue manager that corresponds to one of the transmit queues for the desired DMA channel. Channels may provide more than one TX queue and may provide a particular prioritization policy between the queues. This behavior is application-specific and is controlled by the DMA controller / scheduler implementation.
  5. The queue manager provides a level sensitive status signal for the queue that indicates if any packets are currently pending. This level-sensitive status line is sent to the hardware block that is responsible for scheduling DMA operations.
  6. The DMA controller is eventually brought into context for the corresponding channel and begins to process the packet.
  7. The DMA controller reads the packet descriptor pointer and descriptor size hint information from the queue manager. This is the push value written to the Queue N Reg D registers.
  8. The DMA controller reads the packet descriptor from memory.
  9. The DMA controller empties the buffer (or for linked host packets, each buffer in sequence specified by the next descriptor pointer) by transmitting the contents in one or more block data moves. The size of these blocks is application-specific.
  10. When all data for the packet has been transmitted as specified in the packet size field, the DMA will write the pointer to the packet descriptor to the queue specified in the return queue manager / return queue number fields of the packet descriptor.
  11. After the packet descriptor pointer has been written, the queue manager will indicate the status of the TX completion queues to other ports / processors / prefetcher blocks using out-of-band level sensitive status lines. These status lines are set anytime a queue is non-empty.
  12. While most types of peer entities and embedded processors are able to directly and efficiently use these level sensitive status lines, cached processors may require a hardware block to convert the level status into pulsed interrupts and to perform some level of aggregation of the descriptor pointers from the completion queues into lists.
  13. Host responds to status change from queue manager and performs garbage collection as necessary for packet.

This complete process is shown in Figure 2-2.

Figure 2-2 Packet Transmit OperationPacket_Transmit_Operation.gif