ASIX ELECTRONICS CORPORATION

23

AX88178 L

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

6.2.1.22 GPIO Register (1Fh, write only)

Bit7

Bit6

Bit5

Bit4

Bit3

Bit2

Bit1

Bit0

RSE

Reserved

GPO_2

GPO2EN

GPO_1

GPO1EN

GPO_0

GPO0EN

GPO0EN: Pin GPIO0 Output Enable.

1: Output is enabled (meaning GPIO0 is used as an output pin).

0: Output is tri-stated (meaning GPIO0 is used as an input pin) (default).

GPO_0: Pin GPIO0 Output Value.

GPO1EN: Pin GPIO1 Output Enable.

1: Output is enabled (meaning GPIO1 is used as an output pin).

0: Output is tri-stated (meaning GPIO1 is used as an input pin) (default).

GPO_1: Pin GPIO1 Output Value.

0: (default).

GPO2EN: Pin GPIO2 Output Enable.

1: Output is enabled (meaning GPIO2 is used as an output pin).

0: Output is tri-stated (meaning GPIO2 is used as an input pin) (default).

GPO_2: Pin GPIO2 Output Value.

0: (default).

RSE: Reload Serial EEPROM.

1: Enable.

0: Disabled (default)

6.2.1.23 Software Reset Register (20h, write only)

Bit7

Bit6

Bit5

Bit4

Bit3

Bit2

Bit1

Bit0

0

1

0

BZ

PRL

PRTE

RT

RR

RR: Clear frame length error for Bulk In.

1: set high to clear state.

0: set low to exit clear state (default).

RT: Clear frame length error for Bulk Out.

1: set high to enter clear state.

0: set low to exit clear state (default).

PRTE: External Phy Reset pin Tri-state Enable.

1: Enable, i.e., the external PHYRST_N pin is tri-stated (default). This allows the PHYRST_N pin’s active level to

be controlled by external pulled-up (active high during power-on) or pulled-down resistor (active low during

power-on).

0: Disabled, i.e., the external PHYRST_N pin’s level is driven by either PRL bit or internal “USB RESET” based on

the setting in SCPR bit in Flag byte of EEPROM.

PRL: External Phy Reset pin Level. When SCPR bit = 1 and PRTE = 0, this bit controls the output level of external

PHYRST_N pin.

1: Set to high (default).

0: Set to low.

BZ: Force Bulk In to return a Zero-length packet.

1: Software can force Bulk In to return a zero-length USB packet.

0: Normal operation mode (default).

Bit [7:5]: Please always write 010 to these bits.