Section 23 Gigabit Ethernet Controller (GETHER)
Rev. 1.00 Oct. 01, 2007 Page 969 of 1956
REJ09B0256-0100
23.4.5 CAM
Function
Frames input to the E-MAC are grouped into the following four types; unicast for this LSI,
broadcast, multicast, and unicast to other destinations. The MAC addresses of unicast for this LSI
and broadcast are fixed, and determined only by register settings. Consequently, only multicast
and unicast to other destinations determine whether to receive or not and whether to transfer or not
by using the CAM (unicast frames whose destination MAC addresses match this LSI are called
unicast frames to this LSI, and those that do not are called unicast frames to other destinations).
Furthermore, the evaluation of receive and relay of unicast to other destinations and multicast
frames by using CAM are performed by referencing the registered MAC addresses of the CAM
entry table in the TSU. By using this function, receive FIFO overflow can be prevented caused by
accumulation of frame data not required for reception, and CPU processing for determining
receive can be reduced.
The POST table is composed of 4 bits, and each bit corresponds to port 0 reception, port 1
reception, port 0 to port 1 relay, and port 1 to port 0 relay. When the corresponding bit is set to 1,
the CAM evaluation results are used for determining receive and relay. In other words, when the
corresponding bit of the POST table is cleared to 0, receive and relay evaluation will be the same
as when CAM is not used shown in table 23.4.
The on-chip CAM has entry tables which can register the MAC address of 32 entries, the details
of which can be set by TSU_ADRH0 to TSU_ADRH31 and TSU_ADRL0 to TSU_ADRL31. The
setting to enable/disable referencing of the on-chip CAM entry table is performed by the CAM
entry table enable setting register which sets whether to perform CAM evaluation or not, and the
CAM entry table POST setting register for setting whether to use the CAM determination results
for determining receive or relay. When on-chip CAM entry table referencing during receive is
enabled, the destination address in the frame and MAC address registered in the CAM entry table
are compared, and it is determined whether to transfer the frames input to the E-MAC to E-DMAC
(have E-DMAC receive the frames) or discard the frames. When relaying and CAM entry table
referencing during relay are both enabled, whether to transfer or discard multicast frames and
frames for destinations other than this LSI can be determined by comparing the destination
address in the frame and MAC address registered in the CAM entry table. Table 23.5 shows the
processing method of frames (receive or discard) in reception from E-MAC0 to E-DMAC0 or that
from E-MAC1 to E-DMAC1, while table 23.6 shows the processing for frames in relay from E-
MAC0 to E-MAC1 or that from E-MAC1 to E-MAC0 (relay or discard).
Содержание SH7763
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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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