r5s77631ay266bgv Renesas Electronics Corporation., r5s77631ay266bgv Datasheet - Page 1008

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

Section 23 Gigabit Ethernet Controller (GETHER)
Rev. 1.00 Oct. 01, 2007 Page 942 of 1956
REJ09B0256-0100
Bit
29, 28
Bit
Name
TFP[1:0] 00
Initial
Value
R/W
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
01: The information of the descriptor represents information
10: The information of the descriptor represents information
11: The information of the descriptor represents all
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.
•
•
•
When the number of divisions is large, a descriptor row is
configured by adding intermediate descriptors with TFP[1:0]
= 00.
about the middle of the frame.
about the end of the frame.
about the start of the frame.
information about the frame (single-frame/single-
descriptor (single-buffer)).
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