Signal Descriptions - Samsung KS8910 User Manual

EXTERNAL SIGNALS

SIGNAL DESCRIPTIONS

Signal Pin Number
MEDIA INDEPENDENT INTERFACE (MII) SIGNALS
The MII is the interface between the 10/100 Mbit/s Ethernet Transceiver and a Media Access Control (MAC)
device. MII is a nibble-wide interface clocked at either 2.5MHz or 25 MHz. The Transceiver side MII interface
supplies both the transmit and receive clocks.
Transmit MII Signals
The next sub-table shows the MII signals supported by the 10/100 Mbit/s Ethernet Transceiver for transmitting
data packets. For a detailed description of these signals, see the MII sections of the IEEE 802.3u documents listed
in the reference document section
Col 63
Tx_clk 53
TxD[3:0] 62,61,60,59
Tx_en 58
Tx_er 52
Receive MII Signals
The next sub-table shows the MII signals supported by the 10/100 Mbit/s Ethernet Transceiver for receiving data
RX_CLK packets. For a detailed description of these signals, see the MII sections of the IEEE 802.3u standard
listed in the reference document section.
CrS 64
2-4
Table 2-1. KS8910 Signal Descriptions
I/O
O Collision :
5T Asserted asynchronously with minimum delay from the start of a collision
on the medium.
t/s
O Transmit clock :
5T TxD[3:0] and Tx_en are driven off the rising edge of the Tx_clk by the
MAC, and sampled by the Transceiver on the rising edge of the Tx_clk.
t/s
I Transmit data :
5T Transmit data is aligned on nibble boundaries. TxD[0] corresponds to the
first bit to transmit on the physical medium and is the LSB of the first byte,
PD
followed by the fifth bit of that byte during the next clock.
Transmit enable :
I
Tx_en provides precise framing for the data carried on TxD[3:0]. It is active
5T
during the clock periods that TxD[3:0] contains valid data to be transmitted,
PD
from preamble through CRC.
Transmit coding error :
I
Tx_er is driven synchronously to Tx_clk and is sampled continuously by
5T
the Transceiver. If asserted for one or more Tx_clk periods, it causes the
PD
Transceiver to emit one or more symbols which are not part of the valid
data or delimiter set somewhere in the frame being transmitted.
Carrier sense :
O
Asserted asynchronously with minimum delay from the detection of a non-
5T
idle medium.
t/s
KS8910 100/10 Mbps ETHERNET TRANSCEIVER
Description
Preliminary Spec. ver
1.4