SPRUII0F May 2019 – June 2024 TMS320F28384D , TMS320F28384D-Q1 , TMS320F28384S , TMS320F28384S-Q1 , TMS320F28386D , TMS320F28386D-Q1 , TMS320F28386S , TMS320F28386S-Q1 , TMS320F28388D , TMS320F28388S
31 | 30 | 29 | 28:0 |
---|---|---|---|
OWN | CTXT | DE | Rsvd |
Bit | Name | Description |
---|---|---|
31 | OWN | Own Bit |
When this bit is set, the bit indicates that the DMA owns the descriptor. When this bit is reset, the bit indicates that the application owns the descriptor. The DMA clears this bit when either of the following conditions is true: | ||
The DMA completes the packet reception. | ||
The buffers associated with the descriptor are full. | ||
30 | CTXT | Receive Context Descriptor |
When this bit is set, the bit indicates that the current descriptor is a context descriptor. The DMA writes 1 to this bit for context descriptor. The DMA writes 11 to indicate a descriptor error due to all 1s. | ||
When CTXT and DE bits are used together, {CTXT, DE}: | ||
00: Reserved | ||
01: Reserved | ||
10: Context Descriptor | ||
11: Descriptor Error | ||
Note: When Descriptor Error occurs, the Receive DMA closes the receive descriptor indicating Descriptor Error. This receive descriptor is skipped and the buffer addresses are not used to write the packet data. The Receive DMA sets the CDE bit in DMA_CH#_Status register but not the RI bit even when IOC is set, as this is not marked as last receive descriptor for the packet. The subsequent valid receive descriptor is used to write the packet data. | ||
29 | DE | Descriptor Error |
See the CTXT bit description for details of using theDE bit along with CTXT bit. | ||
28-0 | Rsvd | Reserved |