SH7670 Datasheet, PDF (492/1292 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7670 Series

Section 13 Ethernet Controller Direct Memory Access Controller (E-DMAC)
Initial
Bit
Bit Name value R/W Description
31
CSEBL
1
R/W Operation Setting for Checksum Calculation Function
0: The result of checksum calculation is not written
back to the receive descriptor.
1: The result of checksum calculation is written back
to the receive descriptor.
30
CSMD
1
R/W Setting for Checksum Calculation Mode
0: For all the data skipped from the beginning of
packet, checksums are calculated on the bytes
equivalent to the number of bytes specified in SB5
to SB0.
1: Packet checksums are calculated along with the
analysis of the TCP header.
29 to 6 
All 0
R
Reserved
5 to 0 SB[5:0]^*
011010 R/W
These bits are always read as 0. The write value
should always be 0.
Bytes Skipped in Checksum Calculation
These bits specify the position for starting checksum
calculation from the beginning of a receive packet.
If padding is used, include the padding size and the
padding range when setting the position for starting
checksum calculation.
H'00: Byte 0 (starting data)
H'02: Byte 2
::
H'1A: Byte 26
::
H'3E: Byte 62
Note * Setting is possible only when CSEBL = 1 and CSMD = 0. Otherwise, 6'h00 should be
set.
Rev. 1.00 Nov. 14, 2007 Page 466 of 1262
REJ09B0437-0100