Section 9 Ethernet Controller (EtherC)
Rev. 2.00 Mar 09, 2006 page 413 of 906
REJ09B0292-0200
9.3.7
CAM Match Signal Input Function
The EtherC is equipped with a CAM (Content Addressable Memory) match signal input function.
A CAM circuit is externally connected to compare a destination address in a receive frame (see
figure 9.7). The EtherC receives the result of comparison of a destination address corresponding to
signals (RXD3 to RXD0) fetched from the MII as a signal from a CAMSEN pin and selects
whether the current frame is received or discarded.
SH7616
EtherC
CAMSEN
CAM logic
MII (RX-DV, RXD3 to RXD0)
PHY-LSI
Figure 9.7 CAM Circuit Connection
Table 9.3 shows types of frames received and discarded in the two states of the CAMSEN signal.
The CAM holds the MAC address besides this LSI. When the MAC address which is received
from the PHY-LSI is matched with the destination address held in the CAM, the CAMSEN signal
is asserted. The EtherC recognizes that the CAMSEN signal has been asserted then receives a
frame for the reception.
Some of the frame’s data will have already been stored in the receive FIFO when the CAMSEN
signal is asserted. Therefore, when the E-DMAC is requested that the received data be discarded,
the E-DMAC discards the frame. The frame must be discarded before DMA transfer starts because
the E-DMAC starts transferring to main memory by DMA when at least 16 bytes of data is stored
in the receive FIFO. In this case, according to the MII receive signal timing, the RX-DV is
asserted and the CAMSEN signal must be asserted within 35 clock cycles of the start timing of a
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 ...