
80220/80221
4-5
MD400159/E
5
Pin#
Pin
I/O
Description
44L 64L
28
32
VCC6
—
Positive Supply. 5
± 5% Volts
24
25
VCC5
11
8
VCC4
10
7
VCC3
1
57
VCC2
44
56
VCC1
27
31
GND6
—
Ground. 0 Volts
23
GND5
36
41
GND4
9
6
GND3
4
60
GND2
41
52
GND1
42
54
TPO+
O
Twisted Pair Transmit Output, Positive.
43
55
TPO -
O
Twisted Pair Transmit Output, Negative.
2
58
TPI+
I
Twisted Pair Receive Input, Positive.
3
59
TPI -
I
Twisted Pair Receive Input, Negative.
40
50
REXT
—
Transmit Current Set. An external resistor connected between this pin and GND will set the
output current level for the twisted pair outputs.
37
42
OSCIN
I
Clock Oscillator Input. There must be either a 25 Mhz crystal between this pin and GND or
a 25 Mhz clock applied to this pin. TX_CLK output is generated from this input.
29
34
TX_CLK
O
Transmit Clock Output. This controller interface output provides a clock to an external
controller. Transmit data from the controller on TXD, TX_EN, and TX_ER is clocked in on
rising edges of TX_CLK and OSCIN.
35
40
TX_EN
I
Transmit Enable Input. This controller interface input has to be asserted active high to
indicate that data on TXD and TX_ER is valid, and it is clocked in on rising edges of TX_CLK
and OSCIN.
33
38
TXD3
I
Transmit Data Input. These controller interface inputs contain input nibble data to be
32
37
TXD2
transmitted on the TP outputs, and they are clocked in on rising edges of TX_CLK and OSCIN
31
36
TXD1
when TX_EN is asserted.
30
35
TXD0
34
39
TX_ER /
I
Transmit Error Input. This controller interface input causes a special pattern to be
TXD4
transmitted on the twisted pair outputs in place of normal data, and it is clocked in on rising
edges of TX_CLK when TX_EN is asserted.
If the device is placed in the Bypass 4B5B Encoder mode, this pin is reconfigured to be the
fifth TXD transmit data input, TXD4.
25
26
RX_CLK
O
Receive Clock Output. This controller interface output provides a clock to an external
controller. Receive data on RXD, RX_DV, and RX_ER is clocked out on falling edges of
RX_CLK.
16
13
CRS
O
Carrier Sense Output. This controller interface output is asserted active high when valid data
is detected on the receive twisted pair inputs, and it is clocked out on falling edges of RX_CLK.
17
14
RX_DV
O
Receive Data Valid Output. This controller interface output is asserted active high when valid
decoded data is present on the RXD outputs, and it is clocked out on falling edges of RX_CLK.
19
RXD3
O
Receive Data Output. These controller interface outputs contain receive nibble data from
20
RXD2
the TP input, and they are clocked out on falling edges of RX_CLK.
21
RXD1
22
RXD0
Name
1.0 Pin Description