KS8721B A4 Micrel Inc, KS8721B A4 Datasheet - Page 15

• Manufacturer Part Number: KS8721B A4
• Manufacturer: Micrel Inc

Specifications of KS8721B A4

• Lead Free Status / RoHS Status: Not Compliant

RMII Receive Timing
Auto Crossover (Auto MDI/MDI-X)
Auto Crossover (Auto MDI/MDI-X)
Automatic MDI/MDI-X confi guration is intended to eliminate the need for crossover cables between similar devices.
The assignment of pin-outs for a 10/100 BASE-T crossover function cable is shown below.
This feature can eliminate the confusion in real applications so both straight cable and crossover cable can be used.
This feature is controlled by register 1f:13. See “Register 1fh–100BaseTX PHY Controller” section for details.
March 2006
Parameter
REF_CLK Frequency
RXD[1:0], CRS_DV, RX_ER Output delay from REF_CLK rising edge
RXD[1:0], CRS_DV, RX_ER Output delay from REF_CLK rising edge
RXD[1:0], CRS_DV, RX_ER Output delay from REF_CLK rising edge
RXD[1:0], CRS_DV, RX_ER Output delay from REF_CLK rising edge
RXD[1:0], CRS_DV, RX_ER Output delay from REF_CLK rising edge
RXD[1:0], CRS_DV, RX_ER Output delay from REF_CLK rising edge
REF_CLK
TXD[1:0]
TXEN
TXER
10/100 BASE-T
Media Dependent Interface
10/100 BASE-T
Media Dependent Interface
Modular Connector (RJ45)
Modular Connector (RJ45)
Transmit Pair
Transmit Pair
Receive Pair
Receive Pair
(Repeater or Switch)
(Repeater or Switch)
HUB
HUB
Figure 1. Straight Through Cable
Figure 2. Crossover Cable
“Register 1fh–100BaseTX PHY Controller” section for details.
“Register 1fh–100BaseTX PHY Controller”
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
20ns
t
1
t
2
15
10/100 BASE-T
Media Dependent Interface
10/100 BASE-T
Media Dependent Interface
Modular Connector (RJ45)
Modular Connector (RJ45)
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
(Repeater or Switch)
(Repeater or Switch)
Transmit Pair
HUB
Transmit Pair
HUB
Receive Pair
Receive Pair
Min
2.8
2.8
2.8
2.8
2.8
2.8
Typ
50
Max
10
10
10
10
10
10
M9999-030106
Units
MHz
ns
ns
ns
ns
ns
ns