LAN9420I-NU Standard Microsystems (SMSC), LAN9420I-NU Datasheet - Page 64

• Manufacturer Part Number: LAN9420I-NU
• Manufacturer: Standard Microsystems (SMSC)

Specifications of LAN9420I-NU

• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (max): 3.6V
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 128
• Lead Free Status / RoHS Status: Compliant

Revision 1.4 (12-17-08)
3.5.6.1
3.5.7
3.6
BITS
11:0
10/100 Ethernet PHY
TX Checksum Calculation
The TX checksum calculation is performed using the same operation as the RX checksum, with the
exception that the calculation starts as indicated by the preamble, and the transmitted checksum is the
one’s-compliment of the final calculation.
MAC Control and Status Registers (MCSR)
Please refer to
description of the MCSR.
LAN9420/LAN9420i integrates an IEEE 802.3 Physical Layer for Twisted Pair Ethernet applications
(PHY). The PHY can be configured for either 100 Mbps (100BASE-TX) or 10 Mbps (10BASE-T)
Ethernet operation.
The PHY block includes:
Functionally, the PHY can be divided into the following sections:
TXCSSP - TX Checksum Start Pointer
This field indicates start offset, in bytes, where the checksum calculation will begin in the associated
TX packet.
Note:
Support for auto-negotiation
Automatic polarity detection and correction
HP Auto-MDIX
Energy detect
Duplex, link activity and speed indicator LEDs
Minimal external components are required for the utilization of the integrated PHY
100BASE-TX transmit and receive
10BASE-T transmit and receive
Internal MII interface to the Ethernet Media Access Controller (MAC)
Auto-negotiation to automatically determine the best speed and duplex possible
Management Control to read status registers and write control registers
The data checksum calculation must not begin in the MAC header (first 14 bytes) or in
the last 4 bytes of the TX packet.
Section 4.4, "MAC Control and Status Registers (MCSR)," on page 118
Table 3.20 TX Checksum Preamble (continued)
Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface
DATASHEET
64
DESCRIPTION
SMSC LAN9420/LAN9420i
for a complete
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