SH7670 Datasheet, PDF (514/1292 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7670 Series

Section 13 Ethernet Controller Direct Memory Access Controller (E-DMAC)
13.3.6 Checksum Calculation Function
The TCP checksum for receive packets is accelerated when the checksum calculation function is
used in the following two modes:
• Checksum calculation function of TCP header analysis type
• All-data checksum calculation function of skipped bytes designation type
(1) Checksum Calculation Function of TCP Header Analysis Type (CSEBL = 1 and CSMD
= 1)
Any receive packet included in the table below will be the target of calculation.
IPver
Item
IPv4
No option
Option provided
Fragment*1
IPv6
No extension header
Length of the extension header of a hop-by-hop option
Length of the extension header of routing
Length of the extension header of a fragment*1
Length of the extension header of an end-point option
Length of the extension header of AH
Length of the extension header of ESP*2
Length of the extension header of MobileIPv6*2
Notes: *1. This is the target of calculation, but both RCS15 to RCS0 and RCSE will be undefined
even if the data is normal.
*2. No calculation is performed on RCS15 to RCS0, and RCSE is set to 1.
The following shows the areas as the target of calculation of an IPv4 packet. The shaded portions
are the target of calculation.
Rev. 1.00 Nov. 14, 2007 Page 488 of 1262
REJ09B0437-0100