HD6417618 datasheet(319/646 Pages) RENESAS

Part #	HD6417618

Description	32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7618 Series

PDF	646 Pages

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Manufacturer	RENESAS [Renesas Technology Corp]

Direct Link	http://www.renesas.com

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Section 12 Ethernet Controller Direct Memory Access Controller (E-DMAC)

Rev. 6.00 Jun. 12, 2007 Page 287 of 610

REJ09B0131-0600

(2)

Receive Descriptor

Figure 12.3 shows the relationship between a receive descriptor and the receive buffer. In frame

reception, the E-DMAC performs data rewriting up to a receive buffer 16-byte boundary,

regardless of the receive frame length. Finally, the actual receive frame length is reported in the

lower 16 bits of RD1 in the descriptor. Data transfer to the receive buffer is performed

automatically by the E-DMAC to give a one frame/one buffer or one frame/multi-buffer

configuration according to the size of one received frame.

Receive descriptor

Receive buffer

Valid receive data

RFS26 to RFS0

RD0

RBL

RDL

RD1

RBA

Padding (4 bytes)

RD2

31 30 29 28 27 26

Figure 12.3 Relationship between Receive Descriptor and Receive Buffer

HD6417618 Datasheet(PDF) 319 Page - Renesas Technology Corp