Table 6-4. 4450 GMII/TBI pin descriptions - MAC mode (Host Only) (Sheet 2 of 2)
Pin Name
GMII/TBI Signal
GMII: tx_er
I/O
Description
hx_bus0[9]
out
In GMII mode, asserted high by the 4450 if a
transmit error is detected.
TBI: tx_dat[9]
In TBI mode, additional transmit output.
Used with other TX_DAT outputs to form ten
bit bus TX_DAT[9:0].
hx_bus0[8]
GMII: tx_en
out
out
In GMII mode, valid transmit data driven
high by 4450 on TX_DAT bus.
TBI: tx_dat[8]
In TBI mode, additional transmit output.
Used with other TX_DAT outputs to form ten
bit bus TX_DAT[9:0].
hx_bus0[7:0]
tx_dat[7:0]
Transmit data for GbE: Only TX_DAT[3:0]
used for 10/100FE (MII mode.
Note
hx = h0 or h1
Table 6-5 contains the pin descriptions for either the host ports when configured in PHY
mode.
Table 6-5. 4450 GMII/TBI pin descriptions - PHY mode (Host Only) (Sheet 1 of 2)
Pin Name
GMII/TBI Signal
I/O
Description
hx_ctrl_1
col
N/C
This input should not be connected in this
(PHY) mode.
hx_ctrl_0
hx_clk_2
GMII: crs
N/C
out
This input should not be connected in this
(PHY) mode.
TBI: sigdet
GMII: rx_clk
TBI: rx_pma_clk_1
In GMII mode, receive data clock: sourced
by the PHY from recovered clock from
incoming data. Clock is 125MHz for GbE,
25MHz for 100FE, 2.5MHz for 10Mb Ethernet.
In TBI mode, receive PMA clock 1, 62.5MHz,
clocking odd bytes from TBI interface on the
rising edge of clock.
hx_clk_1
hx_clk_0
GMII: gtx_clk
in
in
In GMII mode, transmit data clock: sourced
by the remove device as a reference clock
for transmitted data. Clock is 125MHz for
GbE.
TBI: txpma_clk
In TBI mode, 125MHz reference for TX_DAT
bus data.
GMII: tx_clk
In GMII mode, transmit data clock: sourced
by the PHY as a reference clock for
transmitted data. Clock is 25MHz for 100FE,
2.5MHz for 10Mb Ethernet.
TBI: rx_pma_clk_0
In TBI mode, receive PMA clock 0, 62.5MHz,
clocking even bytes from TBI interface on the
rising edge of clock.
hx_bus1[9]
GMII: tx_er
in
In GMII mode, asserted high by the remove
device if a transmit error is detected.
TBI: tx_dat[9]
In TBI mode, additional transmit output.
Used with other TX_DAT outputs to form ten
bit bus TX_DAT[9:0].
4450 – Data Sheet, DS-0131-06
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