r5s77631ay266bgv Renesas Electronics Corporation., r5s77631ay266bgv Datasheet - Page 1039

• Manufacturer Part Number: r5s77631ay266bgv
• Description: Renesas 32-bit Risc Microcomputer Superhtm Risc Engine Family Sh-4a Series
• Manufacturer: Renesas Electronics Corporation.

23.4.7
In the E-DMAC, one to three bytes of padding can be inserted in any byte position of receive data
to improve software handling capability. By using this function, for instance, inserting 2-byte
padding after the MAC header (14 bytes) of Ethernet frame enables data following the MAC
header to set in 4-byte boundary.
Padding Insertion in Receive Data
16-byte boundary
16-byte boundary
16-byte boundary
16-byte boundary
16-byte boundary
16-byte boundary
[No padding]
[No padding]
Insert 2-byte padding after 14th byte
Figure 23.14 Padding Insertion in Receive Data
MAC header (14 bytes)
MAC header (14 bytes)
MAC header (14 bytes)
MAC header (14 bytes)
MAC header (14 bytes)
MAC header (14 bytes)
Receive buffer area
Receive buffer area
4 bytes
4 bytes
Section 23 Gigabit Ethernet Controller (GETHER)
Rev. 1.00 Oct. 01, 2007 Page 973 of 1956
2 bytes padding inserted
after MAC header
Padding for separation
at 16-bytes boundary
Padding for separation
at 16 byte boundary
REJ09B0256-0100