r5s77631ay266bgv Renesas Electronics Corporation., r5s77631ay266bgv Datasheet - Page 1046

Manufacturer Part Number

r5s77631ay266bgv

Renesas 32-bit Risc Microcomputer Superhtm Risc Engine Family Sh-4a Series

Manufacturer

Renesas Electronics Corporation.

Section 23 Gigabit Ethernet Controller (GETHER)

1. Start the E-DMAC transmission/reception function

• Set the TR bits in EDTRR to 11.

• Set the RR bit in EDRRR to 1.

2. Start the E-MAC transmission/reception function

• Set the TE and RE bits in ECMR to 1.

23.4.10 Flow Control

The GETHER supports flow control functions conforming to IEEE802.3x for full-duplex

operation. The flow control can be applied to both receive and transmit operations. When

transmitting PAUSE frames, flow control can be performed by the following two procedures :

For receive frames, PAUSE frames are automatically transmitted when the number of data written

to the receive FIFO reaches the value set in FCFTR. The TIME parameter included in the PAUSE

frame is set by APR. The automatic PAUSE frame transmission is repeated until the number of

data in the receive FIFO becomes less than the value set in FCFTR as the receive data is read from

the FIFO. Using TPAUSER, the upper limit of retransmission counts of the PAUSE frames can

also be set in the range from 1 to 65535. In this case, PAUSE frame transmission is repeated until

the number of receive FIFO data becomes less than the FCFTR value, or the number of transmits

reaches the value set by TPAUSER. The transmission counter is cleared to 0 when the next

PAUSE frame is transmitted after the number of data in the receive FIFO becomes less than the

FCFTR value.

The automatic PAUSE frame transmission is enabled when the TXF bit in ECMR is 1.

PAUSE frames are transmitted by directives from the software. When writing the Timer value to

MPR, manual PAUSE frame transmission is started. With this method, PAUSE frame

transmission is carried out only once.

Rev. 1.00 Oct. 01, 2007 Page 980 of 1956

REJ09B0256-0100

Automatic PAUSE Frame Transmission

Manual PAUSE Frame Transmission