Samsung S3C2500B User Manual page 52

PRODUCT OVERVIEW
Group Pin Name
Ethernet MDC_0
Controller0
(18)
MDIO_0
COL_0
TX_CLK_0
TXD0[3:0]/
TXD_10M/
LOOP_10M
1-18
Table 1-1. S3C2500B Signal Descriptions (Continue)
Pin Type Pad Type
1 O
1 I/O
1 I
1 I
4 O
phob12 Management Data Clock.
The signal level at the MDC pin is used as a
timing reference for data transfers that are
controlled by the MDIO signal.
phbcut12 Management Data I/O.
When a read command is being executed,
data that is clocked out of the PHY is
presented on this pin. When a write command
is being executed, data that is clocked out of
the controller is presented on this pin for the
Physical Layer Entity, PHY.
phis Collision Detected/Collision Detected for 10M.
COL is asserted asynchronously with
minimum delay from the start of a collision on
the medium in MII mode. COL_10M is
asserted when a 10-Mbit/s PHY detects a
collision.
phis Transmit Clock/Transmit Clock for 10M.
The controller drives TXD[3:0] and TX_EN
from the rising edge of TX_CLK. In MII mode,
the PHY samples TXD[3:0] and TX_EN on the
rising edge of TX_CLK. For data transfers,
TXCLK_10M is provided by the 10M-bit/s
PHY.
phob12 Transmit Data/Transmit Data for 10M.
Transmit data is aligned on nibble boundaries.
TXD[0] corresponds to the first bit to be
transmitted on the physical medium, which is
the LSB of the first byte and the fifth bit of that
byte during the next clock. TXD_10M is
shared with TXD[0] and is a data line for
transmitting to the 10M-bit/s PHY. LOOP_10M
is shared with TXD[1] and is driven by the
loop-back bit in the control register.
S3C2500B
Description