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RTL8019AS

Realtek Full-Duplex Ethernet Controller with Plug and Play Function (RealPNP)

Realtek Semiconductor 

SPECIFICATION

RTL8019AS

LED1 (LED_RX or LED_CRS)

RTL8019's LED_RX or LED_CRS LED sometimes keeps blinking when the media type of a 2-in-

1 (UTP+BNC) LAN adapter is set to auto-detect and both UTP and coaxial cable are not

connected. In the case, RTL8019 is actually using the BNC because the UTP link test fails. Many

8392 will falsely detect a carrier when the BNC inteface is not properly terminated (e.g. coaxial

cable is not connected). That carrier sense will then make RTL8019's LED_RX or LED_CRS

blink. The problem is that not all 8392s cause the LED blinking, which makes the phenomenon

very ambiguous. Considering the phenomenon is normally awared upon power on, we change

RTL8019's original function to solve the problem to some extent.

The new specification is:

The LED_RX or LED_CRS does not reflect the carrier sense when the CR register bit 0 is set (in

stop mode). Thus, the false carrier due to cabling problem upon power on will not cause the LED1

to blink anymore.

LED Output States in Power Down Modes

LED Output

LEDBNC

LED_LINK

LED_COL

LED_TX

LED_RX

LED_CRS

Normal Mode / Idle

-

-

High

Low

Low

Low

Sleep Mode

-

High

High

High

High

High

Power Down Mode

Low

High

High

High

High

High

6.6. Loopback Diagnostic Operation

6.6.1. Loopback operation

The RTL8019AS provides 3 loopback modes. By loopback test, we can verify the integrity of data

path, CRC logic, address recognition logic and cable connection status.

Mode 1:Loopback through the NIC (LB1=0, LB0=1 in TCR).

The NRZ data is not transmitted to the SNI but instead it's loopbacked to the NIC's Rx

deserializer. The traffic on the cable is ignored.

NIC

Ref: 8390

SNI

83910

Mode 2:Loopback through the SNI (LB1=1, LB0=0 in TCR)

The Manchester encoded data is not transmitted to the MAU. It's loopbacked through

the SNI to NIC. The traffic on the cable is ignored.

NIC

Ref: 8390

SNI

83910

MAU

8392/RTL8005

8019AS.doc

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2001-04-02

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