SPRUGR9H November 2010 – April 2015 66AK2E05 , 66AK2H06 , 66AK2H12 , 66AK2H14 , 66AK2L06 , AM5K2E02 , AM5K2E04 , SM320C6678-HIREL , TMS320C6652 , TMS320C6654 , TMS320C6655 , TMS320C6657 , TMS320C6670 , TMS320C6671 , TMS320C6672 , TMS320C6674 , TMS320C6678
The RX Flow N Configuration Register A contains static configuration information for the RX DMA flow. The fields in this register can be safely changed only when all of the DMA channels that use this flow have been disabled. The fields in this register are shown in Figure 4-27:
31 | 30 | 29 | 28 | 27 | 26 | 25 |
Reserved | RX_EINFO_PRESENT | RX_PSINFO
_PRESENT |
RX_ERROR
_HANDLING |
RX_DESC
_TYPE |
RX_PS
_LOCATION |
W-0 | W-0 | W-0 | W-0 | W-0 | W-0 |
24 | 16 | 15 | 14 | 13 | 12 | 11 | 0 |
RX_SOP_OFFSET | Reserved | RX_DEST
_QMGR |
RX_DEST_QNUM |
W-0 | W-0 | W-0 | W-0 |
Legend: W = Write only; - n = value after reset |
Bit | Field | Description |
---|---|---|
31 | Reserved | Reads return 0 and writes have no effect. |
30 | RX_EINFO_PRESENT | RX Extended Packet Data Block Present: This bit controls whether or not the extended packet info block (EPIB) will be present in the RX packet descriptor.
|
29 | RX_PSINFO_PRESENT | RX Protocol Specific Words Present: This bit controls whether or not the protocol specific words will be present in the RX packet descriptor.
|
28 | RX_ERROR_HANDLING | RX Error Handling Mode: This bit controls the error handling mode for the flow and is used only when channel errors (i.e. descriptor or buffer starvation) occurs:
|
27-26 | RX_DESC_TYPE | RX Descriptor Type: This field indicates the descriptor type to use:
|
25 | RX_PS_LOCATION | RX Protocol Specific Location: This bit controls where the protocol-specific words will be placed in the host mode data structure.
|
24-16 | RX_SOP_OFFSET | RX Start of Packet Offset: For Host packets, this field specifies the number of bytes that are to be skipped in the SOP buffer before beginning to write the payload or Protocol Specific bytes (if PS is located in the SOP buffer). If PS words are located in the SOP buffer, the first word of payload data will immediately follow the last word of PS data. Either way, this field can be used to create a hole at the start of the SOP buffer for software use.
For Monolithic packets, the value of this field must always include the 12 byte descriptor header (offset starts from the descriptor address). So, it must be initialized to be greater than or equal to the size of the descriptor header (12 bytes) plus the size of the maximum number of Protocol Specific words that will be encountered in any of the packets that will be transferred by this flow (if EPIB is present, 20 additional bytes must be added to this offset). This is important as the primary purpose of this field is to ensure that the Protocol Specific words are not overwritten by payload data. The secondary purpose of this field is to allow a hole to be created prior to the payload that can be used by software. Valid values are 0 – 511 bytes. |
15-14 | Reserved | Reads return 0 and writes have no effect. |
13-12 | RX_DEST_QMGR | RX Destination Queue Manager. This field indicates the default receive queue manager that this channel should use. |
11-0 | RX_DEST_QNUM | RX Destination Queue. This field indicates the default receive queue that packets on this flow should be placed onto. |