KSZ8873MLL AM Micrel Inc, KSZ8873MLL AM Datasheet - Page 22

• Manufacturer Part Number: KSZ8873MLL AM
• Description: IC ETHERNET SWITCH 3PORT 64-LQFP
• Manufacturer: Micrel Inc

Specifications of KSZ8873MLL AM

• Controller Type: Ethernet Switch Controller
• Interface: MII
• Voltage - Supply: 1.8V, 2.5V, 3.3V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -
• Lead Free Status / RoHS Status: Not Compliant, Lead free / RoHS Compliant
• Other names: 576-3633; KSZ8873MLL AM; KSZ8873MLLAM

Micrel, Inc.
LinkMD
Port 2 of KSZ8873MLL/FLL/RLL supports the LinkMD
analyze the cabling plant for common cabling problems such as open circuits, short circuits and impedance mismatches.
LinkMD
the shape of the reflected signal. Timing the pulse duration gives an indication of the distance to the cabling fault with
maximum distance of 200m and accuracy of ±2m. Internal circuitry displays the TDR information in a user-readable digital
format.
Note: Cable diagnostics are only valid for copper connections and do not support fiber optic operation.
Access
LinkMD
registers 45, Port Control Register 13.
Alternatively, the MIIM PHY registers 0 and 29 can be used for LinkMD
Usage
The following is a sample procedure for using LinkMD
1. Disable auto MDI/MDI-X by writing a ‘1’ to register 45, bit [2] to enable manual control over the differential pair used to
2. Start cable diagnostic test by writing a ‘1’ to register 42, bit [4]. This enable bit is self-clearing.
3. Wait (poll) for register 42, bit [4] to return a ‘0’, indicating cable diagnostic test is completed.
4. Read cable diagnostic test results in register 42, bits [6:5]. The results are as follows:
5. Get distance to fault by concatenating register 42, bit [0] and register 43, bits [7:0]; and multiplying the result by a
Functional Overview: Power Management
The KSZ8873MLL/FLL/RLL supports a full chip hardware power down mode. When activated (pin PWRDN =0), the entire
chip is powered down.
The KSZ8873MLL/FLL/RLL can also use a single 2.5V power supply instead of 3.3V. It will save about 30% of the power
compared to 3.3V power supply.
The KSZ8873MLL/FLL/RLL supports enhanced power management feature in low power state with energy detection to
ensure low-power dissipation during device idle periods. There are five operation modes under the power management
function which is controlled by two bits in Register 195 (0xC3) and one bit in Register 29 (0x1D),45(0x2D) as shown
below:
Register 195 bit[5:4] = 00 Normal Operation Mode
Register 195 bit[5:4] = 01 Energy Detect Mode
September 2009
transmit the LinkMD
The ‘11’ case, invalid test, occurs when the KSZ8873MLL/FLL/RLL is unable to shut down the link partner. In this
instance, the test is not run, since it would be impossible for the KSZ8873MLL/FLL/RLL to determine if the detected
signal is a reflection of the signal generated or a signal from another source.
constant of 0.4. The distance to the cable fault can be determined by the following formula:
D (distance to cable fault) is expressed in meters.
Concatenated value of registers 42 and 43 is converted to decimal before multiplying by 0.4.
The constant (0.4) may be calibrated for different cabling conditions, including cables with a velocity of propagation
that varies significantly from the norm.
®
®
®
is initiated by accessing registers {42,43}, the LinkMD
works by sending a pulse of known amplitude and duration down the MDI and MDI-X pairs and then analyzes
Cable Diagnostics
00 = normal condition (valid test)
01 = open condition detected in cable (valid test)
10 = short condition detected in cable (valid test)
11 = cable diagnostic test failed (invalid test)
D (distance to cable fault) = 0.4 x {(register 26, bit [0]),(register 27, bits [7:0])}
®
pulse.
®
®.
with registers {42,43,45} on port 2.
The LinkMD
22
®
Control/Status registers for port 2, and in conjunction with
®
feature utilizes time domain reflectometry (TDR) to
®
access.
KSZ8873MLL/FLL/RLL
M9999-092309-1.2