SH7764 Datasheet, PDF (847/1752 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC Engine Family SH-4A Series

Section 20 Ethernet Controller Direct Memory Access Controller (E-DMAC)
(2) Receive Descriptor
Figure 20.3 shows the relationship between a receive descriptor and a receive buffer. The receive
buffer address is to be placed on a 32-byte boundary.
When the receive buffer length (RBL) is set to 0 byte, operation specified by the descriptor cannot
be guaranteed.
Receive descriptor
31 30 29 28 27 26
0
R RR RR
RD0 ^{A D F F F}
C LP PE
RFS
TE1 0
RBL
15
0
RD1
31
16
RFL
31
0
RD2
RBA
Padding (4/20/52 bytes)*
Receive buffer
Valid receive data
Note: * According to the descriptor length (16/32/64 bytes), the padding size is determined.
Figure 20.3 Relationship between Receive Descriptor and Receive Buffer
Rev. 1.00 Nov. 22, 2007 Page 791 of 1692
REJ09B0360-0100