Datasheet

DS_21x3_001 78Q2123/78Q2133 Data Sheet
2.7 LED Signals (Programmability Is Secondary Requirement)
Signal Pin Type Description
LED0 4 CO
PROGRAMMABLE LED. Active low. Default status: LINK OK. Active to
indicate link with far end PHY.
LED1 3 CO PROGRAMMABLE LED. Active low. Default status: RX or TX ACTIVITY.
Active to indicate TX or RX activity on the MDI.
Other LED options selectable via MR23:
TRANSMIT: ON when there is a transmission (normally OFF).
RECEIVE: ON when there is a reception (normally OFF).
COLLISION: In half duplex mode, this is a collision indicator and turns-ON when
a collision occurs. In full duplex mode, this LED is held OFF.
BASE-TX: ON for 100BASE-TX connection and OFF for other
connections. LEDBTX is OFF during auto-negotiation.
BASE-T: ON for 10BASE-T connection and OFF for other connections.
LEDBT is OFF during auto-negotiation.
FULL DUPLEX: ON when in full duplex mode and OFF when in half
duplex mode.
LINK/ACT: ON for link, blink for activity.
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