LAN8187-JT SMSC, LAN8187-JT Datasheet - Page 54

• Manufacturer Part Number: LAN8187-JT
• Description: Ethernet ICs HiPerfrm Ethrnt PHY
• Manufacturer: SMSC
• Type: MII/RMII Ethernet Transceiverr

Specifications of LAN8187-JT

• Ethernet Connection Type: 10 Base-T, 100 Base-TX
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Product: Ethernet Transceivers
• Number Of Transceivers: 1
• Standard Supported: 802.3ab
• Data Rate: 10 MB, 100 MB
• Supply Voltage (max): 3.3 V
• Supply Voltage (min): 1.8 V
• Supply Current (max): 39 mA, 81.6 mA
• Maximum Operating Temperature: + 70 C
• Package / Case: TQFP-64
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Revision 1.7 (03-04-11)
5.4.8
5.4.8.1
5.4.8.2
Ethernet
10/100
MAC
The Full-Duplex LED output is driven active low when the link is operating in Full-Duplex mode.
Loopback Operation
The LAN8187/LAN8187i may be configured for near-end loopback and far loopback.
Near-end Loopback
Near-end loopback is a mode that sends the digital transmit data back out the receive data signals for
testing purposes as indicated by the blue arrows in
by setting bit register 0 bit 14 to logic one.
A large percentage of the digital circuitry is operational near-end loopback mode, because data is
routed through the PCS and PMA layers into the PMD sublayer before it is looped back. The COL
signal will be inactive in this mode, unless collision test (bit 0.7) is active. The transmitters are powered
down, regardless of the state of TXEN.
Far Loopback
Far loopback is a special test mode for MDI (analog) loopback as indicated by the blue arrows in
Figure
data that is received from the link partner on the MDI is looped back out to the link partner. The digital
interface signals on the local MAC interface are isolated.
5.3. The far loopback mode is enabled by setting bit register 17 bit 9 to logic one. In this mode,
TXD
RXD
Figure 5.2 Near-end Loopback Block Diagram
Digital
Ethernet Transceiver
SMSC
±15kV ESD Protected MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX & flexPWR
DATASHEET
Analog
54
X
X
Figure
TX
RX
5.2.The near-end loopback mode is enabled
XFMR
SMSC LAN8187/LAN8187i
CAT-5
Datasheet
®
Technology