Section 23 Gigabit Ethernet Controller (GETHER)
Rev. 1.00 Oct. 01, 2007 Page 966 of 1956
REJ09B0256-0100
(2) Reception Error Processing
(a) Reception
Error
When a reception error occurs, the FR and RABT bits in EESR are set to 1 and an interrupt is
issued to the CPU after a write-back operation for the receive descriptor related to the reception
error frame.
If a reception error occurs when the length of the frame received from the GMII/MII/RMII is less
than 32 bytes, DMA transfer to the receive buffer for the frame is not performed. At this time, the
receive frame is discarded in the E-DMAC (flush function). However, if padding is inserted in the
receive frame by RPADIR, the flush function is performed when the frame length including the
padding bytes is less than 32 bytes.
(b) Receive
FIFO
Overflow
In any of the following cases, the E-MAC cannot receive frames from the GMII/MII/RMII
because it has no space to store receive frames, and all the receive frames that have been
transferred to the E-MAC will be discarded in the E-MAC (receive FIFO overflow).
•
Receive FIFO is full of data waiting for DMA transfer (the receive FIFO has no space).
•
The number of receive frames waiting for DMA transfer is 24 in total (the receive frame
information managing area has no empty space; up to 24 frames can be managed).
If an overflow occurs due to the former case, the RFE bit in EESR is set to 1 and an interrupt is
generated to the CPU. If an overflow occurs due to the latter case, the RFCOF bit in EESR is set
to 1 and an interrupt is generated to the CPU. Each time a receive frame is discarded due to an
overflow, RMFCR is incremented. However, RMFCR is not incremented for a receive frame that
is cut off due to insufficient receive FIFO space. If a receive frame is cut off due to insufficient
receive FIFO space (the frame is partially stored in the receive FIFO), the E-DMAC performs the
following operation:
•
Performs DMA transfers for the cut-off frame stored in the receive FIFO to the receive buffer.
•
After the DMA transfer, performs a write-back operation on the receive descriptor.
•
After the write-back operation, sets the ROC bit in EESR to 1 and generates an interrupt to the
CPU.
When the receive FIFO is full of data waiting for DMA transfer, frame reception from the
GMII/MII/RMII can be resumed if DMA transfer is performed from the receive FIFO to the
receive buffer and 32 bytes or more of empty space is generated in the receive FIFO. When the
number of receive frames waiting for DMA transfer is 24 in total, frame reception from the
GMII/MII/RMII can be resumed if one or more frame has been DMA transferred from the receive
Содержание SH7763
Страница 2: ...Rev 1 00 Oct 01 2007 Page ii of lxvi ...
Страница 122: ...Section 2 Programming Model Rev 1 00 Oct 01 2007 Page 56 of 1956 REJ09B0256 0100 ...
Страница 144: ...Section 3 Instruction Set Rev 1 00 Oct 01 2007 Page 78 of 1956 REJ09B0256 0100 ...
Страница 170: ...Section 4 Pipelining Rev 1 00 Oct 01 2007 Page 104 of 1956 REJ09B0256 0100 ...
Страница 282: ...Section 7 Caches Rev 1 00 Oct 01 2007 Page 216 of 1956 REJ09B0256 0100 ...
Страница 378: ...Section 9 Interrupt Controller INTC Rev 1 00 Oct 01 2007 Page 312 of 1956 REJ09B0256 0100 ...
Страница 514: ...Section 12 DDR SDRAM Interface DDRIF Rev 1 00 Oct 01 2007 Page 448 of 1956 REJ09B0256 0100 ...
Страница 630: ...Section 13 PCI Controller PCIC Rev 1 00 Oct 01 2007 Page 564 of 1956 REJ09B0256 0100 ...
Страница 686: ...Section 14 Direct Memory Access Controller DMAC Rev 1 00 Oct 01 2007 Page 620 of 1956 REJ09B0256 0100 ...
Страница 710: ...Section 16 Clock Pulse Generator CPG Rev 1 00 Oct 01 2007 Page 644 of 1956 REJ09B0256 0100 ...
Страница 732: ...Section 17 Watchdog Timer and Reset WDT Rev 1 00 Oct 01 2007 Page 666 of 1956 REJ09B0256 0100 ...
Страница 752: ...Section 18 Power Down Mode Rev 1 00 Oct 01 2007 Page 686 of 1956 REJ09B0256 0100 ...
Страница 772: ...Section 19 Timer Unit TMU Rev 1 00 Oct 01 2007 Page 706 of 1956 REJ09B0256 0100 ...
Страница 824: ...Section 21 Compare Match Timer CMT Rev 1 00 Oct 01 2007 Page 758 of 1956 REJ09B0256 0100 ...
Страница 1060: ...Section 23 Gigabit Ethernet Controller GETHER Rev 1 00 Oct 01 2007 Page 994 of 1956 REJ09B0256 0100 ...
Страница 1062: ...Section 24 IP Security Accelerator SECURITY Rev 1 00 Oct 01 2007 Page 996 of 1956 REJ09B0256 0100 ...
Страница 1124: ...Section 26 I 2 C Bus Interface IIC Rev 1 00 Oct 01 2007 Page 1058 of 1956 REJ09B0256 0100 ...
Страница 1184: ...Section 27 Serial Communication Interface with FIFO SCIF Rev 1 00 Oct 01 2007 Page 1118 of 1956 REJ09B0256 0100 ...
Страница 1350: ...Section 30 SIM Card Module SIM Rev 1 00 Oct 01 2007 Page 1284 of 1956 REJ09B0256 0100 ...
Страница 1484: ...Section 33 Audio Codec Interface HAC Rev 1 00 Oct 01 2007 Page 1418 of 1956 REJ09B0256 0100 ...
Страница 1560: ...Section 35 USB Host Controller USBH Rev 1 00 Oct 01 2007 Page 1494 of 1956 REJ09B0256 0100 ...
Страница 1720: ...Section 37 LCD Controller LCDC Rev 1 00 Oct 01 2007 Page 1654 of 1956 REJ09B0256 0100 ...
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Страница 2026: ...SH7763 Hardware Manual ...