Section 10 Ethernet Controller Direct Memory Access Controller (E-DMAC)
Rev. 2.00 Mar 09, 2006 page 459 of 906
REJ09B0292-0200
10.3.4
Multi-Buffer Frame Transmit/Receive Processing
Multi-Buffer Frame Transmit Processing:
If an error occurs during multi-buffer frame
transmission, the processing shown in figure 10.6 is carried out.
Where the transmit descriptor is shown as inactive (TACT bit = 0) in the figure, buffer data has
already been transmitted normally, and where the transmit descriptor is shown as active (TACT bit
= 1), buffer data has not been transmitted. If a frame transmit error occurs in the first descriptor
part where the transmit descriptor is active (TACT bit = 1), transmission is halted, and the TACT
bit cleared to 0, immediately. The next descriptor is then read, and the position within the transmit
frame is determined on the basis of bits TFP1 and TFP0 (continuing [00] or end [01]). In the case
of a continuing descriptor, the TACT bit is cleared to 0, only, and the next descriptor is read
immediately. If the descriptor is the final descriptor, not only is the TACT bit cleared to 0, but
write-back is also performed to the TFE and TFS bits at the same time. Data in the buffer is not
transmitted between the occurrence of an error and write-back to the final descriptor. If error
interrupts are enabled in the EtherC/E-DMAC status interrupt permission register (EESIPR), an
interrupt is generated immediately after the final descriptor write-back.
0 0
0 0
0 0
1 0
1 0
1 0
1 0
1 0
1 1
1 0
0 0
0 0
0 0
0 0
0 0
0 0
0 1
1 0
E-DMAC
Inactivates TACT (changes 1 to 0)
Descriptor read
Descriptor read
Descriptor read
Descriptor read
Inactivates TACT
Inactivates TACT
Inactivates TACT
Inactivates TACT and writes TFE, TFS
Descriptors
One frame
Buffer
Transmitted data
Untransmitted data
Transmit error occurrence
Untransmitted
data is not
transmitted
after error
occurrence.
Descriptor
TACT
TDLE
TFP1
TFP0
Figure 10.6 E-DMAC Operation after Transmit Error
Multi-Buffer Frame Receive Processing:
If an error occurs during multi-buffer frame reception,
the processing shown in figure 10.7 is carried out.
Where the receive descriptor is shown as inactive (RACT bit = 0) in the figure, buffer data has
already been received normally, and where the receive descriptor is shown as active (RACT bit =
Содержание SH7616
Страница 10: ...Rev 2 00 Mar 09 2006 page x of xxvi ...
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 ...