SH7763 Datasheet, PDF (1008/2026 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC Engine Family SH-4A Series

Section 23 Gigabit Ethernet Controller (GETHER)
Bit
29, 28
Bit
Initial
Name Value R/W
TFP[1:0] 00
R/W
Description
Transmit Frame Position
These bits indicate whether information of this descriptor
represents information about the start, middle, or end of the
transmit frame.
00: The information of the descriptor represents information
about the middle of the frame.
01: The information of the descriptor represents information
about the end of the frame.
10: The information of the descriptor represents information
about the start of the frame.
11: The information of the descriptor represents all
information about the frame (single-frame/single-
descriptor (single-buffer)).
Reference
When one frame is divided for use, the method of specifying
this bit for a descriptor row according to the number of
divisions is described below.
• For single-frame/single-descriptor operation
First descriptor: TFP[1:0] = 11
• For single-frame/two-descriptor operation
First descriptor: TFP[1:0] = 10
Second descriptor: TFP[1:0] = 01
• For single-frame/three-descriptor operation
First descriptor: TFP[1:0] = 10
Second descriptor: TFP[1:0] = 00
Third descriptor: TFP[1:0] = 01
When the number of divisions is large, a descriptor row is
configured by adding intermediate descriptors with TFP[1:0]
= 00.
Rev. 1.00 Oct. 01, 2007 Page 942 of 1956
REJ09B0256-0100