CS8904
Crystal LAN™ Quad Ethernet Transceiver
AUTONEG[0:3] - Auto-Negotiation Status. Output with 4 mA drive, Pins 100, 80, 50, and 30.
This output remains high when Auto-Negotiation has taken place successfully, and remains low
when Auto-Negotiation has failed or is disabled for this port. See Section 4.3.2 (Control and
Status Information) for more information.
RxDATA[0:3] - Received Data. Output with 4 mA drive, Pins 95, 85, 45, and 35.
The data received for this port is output on this pin. This data is NRZ encoded and is
synchronized using the receive clock, RxCLK. The CD pin is asserted when receive data is
present on the RxDATA pin.
JABBER[0:3] - Jabber. Output with 4 mA drive, Pins 97, 83, 47, and 33.
This output pin will assert to indicate that a jabber condition has been detected for this port.
RxCLK[0:3] - Recovered Receive Clock. Output with 4 mA drive, Pins 94, 86, 44, and 36.
The recovered receive clock for the port is output on this pin.
2.2 10BASE-T Interface
TX+[0:3], TX-[0:3] - 10BASE-T Transmit Pair. Output, Pins 10, 69, 60, 19, 11, 70, 61, and 20.
Differential output pair that drives 10 Mb/s Manchester-encoded data to the 10BASE-T twisted-
pair segment.
RX+[0:3], RX-[0:3] - 10BASE-T Receive Pair. Input, Pins 6, 73, 56, 23, 7, 74, 57, and 24.
Differential input pair that receives 10 Mb/s Manchester-encoded data from the 10BASE-T
twisted-pair segment.
2.3 LED Pins
LINKLED[0:3] - Link Status LED. Open Drain Output with 10 mA drive, Pins 96, 84, 46, and 34.
This active-low output goes low and remains continuously low for a functioning 10BASE-T
link. Refer to Section 4.3.2 (Control and Status Information) for more information on using the
LINKLED pin.
2.4 General Pins
XTAL1, XTAL2 - Crystal. Input, Output, Pins 38 and 39.
A 20 MHz crystal should be connected across these pins. Alternatively, a 20 MHz signal may
be connected to XTAL1; XTAL2 is left open.
RESET - Reset. Input with Internal Weak Pullup, Pin 66.
Setting this pin low for at least 500 ns will reset the CS8904.
CIRRUS LOGIC ADVANCED PRODUCT DATABOOK
DS191PP2
9
CIRRUS [ CIRRUS LOGIC ]
