AM79C973BKD\W AMD (ADVANCED MICRO DEVICES), AM79C973BKD\W Datasheet - Page 36

• Manufacturer Part Number: AM79C973BKD\W
• Manufacturer: AMD (ADVANCED MICRO DEVICES)

Specifications of AM79C973BKD\W

• Lead Free Status / RoHS Status: Compliant

Start of Frame Delimiter is driven on RXD[3:0], and
must remain asserted until after the rising edge of
RX_CLK, when the last nibble of the CRC is driven on
RXD[3:0]. RX_DV must then be deasserted prior to the
RX_CLK rising edge which follows this final nibble.
RX_DV transitions are synchronous to RX_CLK rising
edges.
Note: The RX_DV pin is multiplexed with the
EBD4 pin.
External Address Detection Interface
EAR
External Address Reject Low
The incoming frame will be checked against the inter-
nally active address detection mechanisms and the re-
sult of this check will be OR’d with the value on the EAR
pin. The EAR pin is defined as REJECT. The pin value
is OR’d with the internal address detection result to de-
termine if the current frame should be accepted or re-
jected.
The EAR pin must not be left unconnected, it should
be tied to VDD through a 10-k
When RST is active, EAR is an input for NAND tree
testing.
SFBD
Start Frame-Byte Delimiter
An initial rising edge on the SFBD signal indicates that
a start of valid data is present on the RXD[3:0] pins.
SFBD will go high for one nibble time (400 ns when op-
erating at 10 Mbps and 40 ns when operating at 100
Mbps) one RX_CLK period after RX_DV has been as-
serted and RX_ER is deasserted and the detection of
the SFD (Start of Frame Delimiter) of a received frame.
Data on the RXD[3:0] will be the start of the destination
address field. SFBD will subsequently toggle every nib-
ble time (1.25 MHz frequency when operating at 10
Mbps and 12.5 MHz frequency when operating at 100
Mbps) indicating the first nibble of each subsequent
byte of the received nibble stream. The RX_CLK
should be used in conjunction with the SFBD to latch
the correct data for external address matching. SFBD
will be active only during frame reception.
Note: The SFBD pin is multiplexed with the EESK and
LED1 pins.
MIIRXFRTGD
MII Receive Frame Tag Enable
When the EADI is enabled (EADISEL, BCR2, bit 3), the
Receive Frame Tagging is enabled (RXFRTG, CSR7,
bit 14), and the MII Snoop mode is selected, the MIIRX-
FRTGD pin becomes a data input pin for the Receive
Frame Tag. See the Receive Frame Tagging section for
details.
36
±
5% resistor.
P R E L I M I N A R Y
Am79C973/Am79C975
Output
Input
Input
Note: The MIIRXFRTGD pin is multiplexed with the
EEDO and LED3 pins.
MIIRXFRTGE
MII Receive Frame Tag Enable
When the EADI is enabled (EADISEL, BCR2, bit 3), the
Receive Frame Tagging is enabled (RXFRTG, CSR7,
bit 14), and the MII Snoop mode is selected, the MIIRX-
FRTGE pin becomes a data input enable pin for the Re-
ceive Frame Tag. See the Receive Frame Tagging
section for details.
Note: The MIIRXFRTGE pin is multiplexed with the
LED2 pin.
IEEE 1149.1 (1990) Test Access Port
Interface
TCK
Test Clock
TCK is the clock input for the boundary scan test mode
operation. It can operate at a frequency of up to 10
MHz. TCK has an internal pull up resistor.
TDI
Test Data In
TDI is the test data input path to the Am79C973/
Am79C975 controller. The pin has an internal pull up
resistor.
TDO
Test Data Out
TDO is the test data output path from the Am79C973/
Am79C975 controller. The pin is tri-stated when the
JTAG port is inactive.
TMS
Test Mode Select
A serial input bit stream on the TMS pin is used to de-
fine the specific boundary scan test to be executed.
The pin has an internal pull up resistor.
Network Interfaces
TX+, TX-
Serial Transmit Data
MLT-3/PECL
These pins are the 10BASE-T/100BASE-X differential
drivers. For 100BASE-FX, these transmit outputs carry
differential PECL-level NRZI data for direct connection
to an external fiber optic transceiver. They can be
forced to logical 0 (TX+ low, TX- high) by programming
the TX_DISABLE bit (bit 3 of the internal PHY Control/
Status Register, Register 17). For 100BASE-TX, these
pins carry MLT-3 data and are connected to the primary
side of the magnetics module. For 10BASE-T, these
Output
Output
Input
Input
Input
Input