SH7713 datasheet(745/904 Pages) RENESAS

745 / 904 page

Section 19 Ethernet Controller Direct Memory Access Controller (E-DMAC)

Rev.1.50 Aug. 30, 2006 Page 705 of 860

REJ09B0288-0150

Bit

Bit Name

Initial

Value

R/W

Description

RFP1

RFP0

R/W

Receive Frame Position 1, 0

The E-DMAC indicates by write-back operation

whether information of the corresponding descriptor

represents information about the start, middle, or end

of the receive 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:

The relationship between a frame after reception of

one frame and a descriptor is described below.

[For single-frame/single-descriptor operation]

First descriptor: RFP[1:0] = 11

[For single-frame/two-descriptor operation]

First descriptor: RFP[1:0] = 10

Second descriptor: RFP[1:0] = 01

[For single-frame/three-descriptor operation]

First descriptor: RFP[1:0] = 10

Second descriptor: RFP[1:0] = 00

Third descriptor: RFP[1:0] = 01

When the number of divisions is large, a descriptor

row is configured by adding intermediate descriptors

with RFP[1:0] = 00.

SH7713 Datasheet(PDF) 745 Page - Renesas Technology Corp