Section 10 Ethernet Controller Direct Memory Access Controller (E-DMAC)
Rev. 2.00 Mar 09, 2006 page 452 of 906
REJ09B0292-0200
Receive descriptor
Receive buffer
RACT
RDLE
RFP1
RFP0
RFE
RFS 26 to RFS0
RD0
RBL
RDL
0
0
31
31 30 29 28
26
27
31
RD1
RBA
Padding (4 bytes)
RD2
Valid receive data
16 15
Figure 10.3 Relationship between Receive Descriptor and Receive Buffer
Receive Descriptor 0 (RD0):
RD0 indicates the receive frame status. The CPU and E-DMAC use
RD0 to report the frame transmission status.
Bit 31—Receive Descriptor Active (RACT): Indicates that this descriptor is active. The E-DMAC
resets this bit after receive data has been transferred to the receive buffer. On completion of
receive frame processing, the CPU sets this bit to prepare for reception.
Bit 31: RACT
Description
0
The receive descriptor is invalid
Indicates that the receive buffer is not ready (access disabled by E-DMAC), or
this bit has been reset by a write-back operation on termination of E-DMAC
frame transfer processing (completion or suspension of reception)
If this state is recognized in an E-DMAC descriptor read, the E-DMAC
terminates receive processing and receive operations cannot be continued
Reception can be restarted by setting RACT to 1 and executing receive
initiation.
1
The receive descriptor is valid
Indicates that the receive buffer is ready (access enabled) and processing for
frame transfer from the FIFO has not been executed, or that frame transfer is in
progress
When this state is recognized in an E-DMAC descriptor read, the E-DMAC
continues with the receive operation
Содержание SH7616
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Страница 132: ...Section 2 CPU Rev 2 00 Mar 09 2006 page 106 of 906 REJ09B0292 0200 ...
Страница 568: ...Section 12 16 Bit Free Running Timer FRT Rev 2 00 Mar 09 2006 page 542 of 906 REJ09B0292 0200 ...
Страница 582: ...Section 13 Watchdog Timer WDT Rev 2 00 Mar 09 2006 page 556 of 906 REJ09B0292 0200 ...
Страница 662: ...Section 14 Serial Communication Interface with FIFO SCIF Rev 2 00 Mar 09 2006 page 636 of 906 REJ09B0292 0200 ...
Страница 706: ...Section 16 Serial I O SIO Rev 2 00 Mar 09 2006 page 680 of 906 REJ09B0292 0200 ...
Страница 820: ...Section 19 Pin Function Controller PFC Rev 2 00 Mar 09 2006 page 794 of 906 REJ09B0292 0200 ...
Страница 932: ...Appendix D Package Dimensions Rev 2 00 Mar 09 2006 page 906 of 906 REJ09B0292 0200 ...
Страница 935: ...SH7616 Hardware Manual ...