ASIX ELECTRONICS CORPORATION

21

AX88178 L

USB to 10/100/1000 Gigabit Ethernet/HomePNA Controller

6.2.1.18 Medium Status Register (1Ah, read only) and Medium Mode Register (1Bh, write only)

Bit7

Bit6

Bit5

Bit4

Bit3

Bit2

Bit1

Bit0

PF

JFE

TFC

RFC

ENCK

AC

FD

GM

Reserved

SM

SBP

Reserved

PS

RE

AA [7:0] = {PF, JFE, TFC, RFC, EN125, AC, FD, GM}.

BB [7:0] = {Reserved, SM, SBP, JE, PS, RE}.

GM: Gigabit Mode.

1: GMII mode.

0: MII mode (default).

PS: Port Speed in MII mode

1: 100 Mbps (default).

0: 10 Mbps.

{GM, PS} RGMII/MII/GMII port speed selection

00: 10Mbps

01: 100Mbps

10: 1000Mbps

11: 1000Mbps

FD: Full Duplex mode

1: Full Duplex mode (default).

0: Half Duplex mode.

AC: Reserved bit. For normal operation, please always write 1 to this bit.

ENCK: Enable GTX_CLK and TXC clock outputs

1: Enable.

0: Disabled (default).

ENCK RGMII_EN GTX_CLK

TXC

0

0

OFF

OFF

0

1

OFF

OFF

1

0

ON

OFF

1

1

OFF

ON

RFC: RX Flow Control enable.

1: Enable receiving of pause frame on RX direction during full duplex mode (default).

0: Disabled.

TFC: TX Flow Control enable.

1: Enable transmitting pause frame on TX direction during full duplex mode (default).

0: Disabled.

JFE: Jumbo Frame Enable.

1: Enable the support of Jumbo frame in Gigabit mode (default).

0: Disabled.

PF: Check only “length/type” field for Pause Frame.

1: Enable, i.e., Pause frames are identified only based on L/T filed.

0: Disabled, i.e., Pause frames are identified based on both DA and L/T fields (default).

RE: Receive Enable.

1: Enable RX path of the ASIC.

0: Disabled (default).

SBP: Stop BackPressure.

1: When TFC bit = 1, setting this bit enables backpressure on TX direction “continuously” during RX buffer full

condition in half duplex mode.

0: When TFC bit = 1, setting this bit enable backpressure on TX direction “intermittently” during RX buffer full

condition in half duplex mode (default).

SM: Super Mac support.

1: Enable Super Mac to shorten exponential back-off time during transmit retry.

0: Disabled (default).