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
KSZ8873MLL/FLL/RLL supports the LinkMD
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. 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
for ports 1 and 2 respectively; and in conjunction with the port registers control 13 for ports 1and 2 respectively to disable
Auto MDI/MDIX.
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 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[1:0] = 00 Normal Operation Mode
Register 195 bit[1:0] = 01 Energy Detect Mode
Register 195 bit[1:0] = 10 Soft Power Down Mode
Register 195 bit[1:0] = 11 Power Saving Mode
Register 29,45 bit 3 =1 Port Based Power Down Mode
Table 3 indicates all internal function blocks status under four different power management operation modes.
September 2010
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.
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is initiated by accessing the PHY special control/status registers {26, 42} and the LinkMD result registers {27, 43}
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])}
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pulse.
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. The LinkMD
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with registers {42,43,45} on port 2.
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feature utilizes time domain reflectometry (TDR) to analyze
22
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access.
KSZ8873MLL/FLL/RLL
M9999-092309-1.2