KS8721CL
Micrel, Inc.
KS8721CL
3.3V Single Power Supply 10/100BASE-TX/FX MII Physical Layer Transceiver
Rev. 1.2
General Description
The KS8721CL is a 10BASE-T, 100BASE-TX, and 100BASE-
FX physical layer transceiver providing MII/RMII interfaces to
MACs and switches. Using a unique mixed-signal design that
extends signaling distance while reducing power consump-
tion, the KS8721CL represents Micrel’s fourth generation
single-port Fast Ethernet PHY.
The KS8721CL contains 10BASE-T physical medium attach-
ment (PMA), physical medium dependent (PMD), and physi-
cal coding sub-layer (PCS) functions. It also has on-chip
10BASE-T output filtering. This eliminates the need for
external filters and allows a single set of line magnetics to be
used to meet requirements for both 100BASE-TX and
10BASE-T.
The KS8721CL automatically configures itself for 100Mbps
or 10Mbps and full- or half-duplex operation, using an on-chip
auto-negotiation algorithm. It is the ideal physical layer
transceiver for 100BASE-TX/10BASE-T applications.
Features
• Single chip 100BASE-TX/100BASE-FX/10BASE-T
physical layer solution
• 2.5V CMOS design; 2.5/3.3V tolerance on I/O
• 3.3V single power supply with built-in voltage regulator;
Power consumption <340mW (including output driver
current)
• Fully compliant to IEEE 802.3u standard
• Supports MII and Reduced MII (RMII)
• Supports 10BASE-T, 100BASE-TX, and 100BASE-FX
with far-end-fault (FEF) detection
• Supports power-down and power-saving modes
• Configurable through MII serial management ports or via
external control pins
• Supports auto-negotiation and manual selection for
10/100Mbps speed and full-/half-duplex modes
• On-chip, built-in, analog front-end filtering for both
100BASE-TX and 10BASE-T
• Available in Lead-free and Industrial Temperature
packages.
Functional Diagram
NRZ/NRZI
MLT3 Encoder
4B/5B Encoder
Scrambler
Parallel/Serial
Parallel/Serial
Manchester Encoder
MII/RMII
Registers
and
Controller
Interface
TX+
TX-
Transmitter
10/100
Pulse
Shaper
TXD3
TXD2
TXD1
TXD0
TXER
TXC
TXEN
CRS
COL
MDIO
MDC
RXD3
RXD2
RXD1
RXD0
RXER
RXDV
RXC
RX+
RX-
Adaptive EQ
Base Line
Wander Correction
MLT3 Decoder
NRZI/NRZ
Clock
Recovery
4B/5B Decoder
Descrambler
Serial/Parallel
Auto
Negotiation
10BaseT
Receiver
Power
Down or
Saving
XI
XO
PLL
PWRDWN
Manchester Decoder
Serial/Parallel
LINK
LED
Driver
ACTIVITY
FDX
SPD
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
April 2005
1
M9999-041405
KS8721CL
Micrel, Inc.
(continued)
Features
Ordering Information
Part Number
KS8721CL
KSZ8721CL
Temp. Range
0°C to +70°C
0°C to +70°C
Package
48-Pin LQFP
48-Pin LQFP
Lead Finish
Standard
Lead-free
• LED outputs for link, activity, full-/half-duplex, and speed
• Supports back-to-back, FX to TX for media converter
applications
• Supports MDI/MDI-X auto-crossover
• Commercial temperature range: 0°C to +70°C
• Industrial temperature range: –40°C to +85°C
• Available in 48-pin LQFP
M9999-041405
2
April 2005
KS8721CL
Micrel, Inc.
Revision History
Revision
0.90
1.0
1.1
Date
7/20/04
10/08/04
1/27/05
Summary of Changes
Created.
Updated series resistance for crystal specification to 40Ω.
MDIO resistor value changes to 4.7kΩ.
Added note on strapping option pins. Updated bits 1b.0 - 1b.7 to self-clearing.
Updated Electrical characteristics.
Updated reference schematic for strapping option configuration to 3.3V.
Updated bits 1f.4-1f.2 to reserved. Added aditional magnetics to qualified transformer table.
Added reset reference circuit.
Added RMII timing.
Corrected LED signal references to collision.
Removed KS8721CLI from ordering information.
1.2
3/16/05
April 2005
3
M9999-041405
KS8721CL
Micrel, Inc.
Table Of Contents
Pin Description ............................................................................................................................................................ 6
Strapping Option ......................................................................................................................................................... 9
Pin Configuration ...................................................................................................................................................... 10
Introduction ........................................................................................................................................................... 11
100BASE-TX Transmit ........................................................................................................................................ 11
100BASE-TX Receive ......................................................................................................................................... 11
PLL Clock Synthesizer ......................................................................................................................................... 11
Scrambler/De-scrambler (100BASE-TX only) ..................................................................................................... 11
10BASE-T Transmit ............................................................................................................................................. 11
10BASE-T Receive .............................................................................................................................................. 11
SQE and Jabber Function (10BASE-T only) .......................................................................................................
Auto-Negotiation ..................................................................................................................................................
MII Management Interface ...................................................................................................................................
MII Data Interface ................................................................................................................................................
11
11
12
12
Transmit Clock ............................................................................................................................................. 12
Receive Clock .............................................................................................................................................. 12
Transmit Enable ........................................................................................................................................... 12
Receive Data Valid ...................................................................................................................................... 12
Error Signals ................................................................................................................................................ 12
Carrier Sense ............................................................................................................................................... 12
Collision ........................................................................................................................................................
RMII (Reduced MII) Data Interface .....................................................................................................................
RMII Signal Definition ..........................................................................................................................................
Reference Clock ..................................................................................................................................................
Carrier Sense/Receive Data Valid .......................................................................................................................
Receive Data .......................................................................................................................................................
Transmit Enable ...................................................................................................................................................
Transmit Data ......................................................................................................................................................
Collision Detection ...............................................................................................................................................
RX_ER
...........................................................................................................................................................
RMII AC Characteristics ......................................................................................................................................
Unused RMII Pins ................................................................................................................................................
Auto-Crossover (Auto-MDI/MDI-X) ......................................................................................................................
Power Management .............................................................................................................................................
100BT FX Mode ..................................................................................................................................................
Media Converter Operation .................................................................................................................................
Circuit Design Reference for Power Supply ........................................................................................................
Register Map ...........................................................................................................................................................
Register 0h: Basic Control ..................................................................................................................................
Register 1h: Basic Status ...................................................................................................................................
Register 2h: PHY Identifier 1 ..............................................................................................................................
Register 3h: PHY Identifier 2 ..............................................................................................................................
Register 4h: Auto-Negotiation Advertisement .....................................................................................................
Register 5h: Auto-Negotiation Link Partner Ability ..............................................................................................
Register 6h: Auto-Negotiation Expansion ...........................................................................................................
Register 7h: Auto-Negotiation Next Page ...........................................................................................................
Register 8h: Link Partner Next Page Ability ........................................................................................................
M9999-041405
13
13
13
13
13
13
13
14
14
14
14
14
15
16
16
16
17
18
18
18
19
19
19
19
20
20
20
4
April 2005
KS8721CL
Micrel, Inc.
21
21
21
23
23
23
25
31
31
32
Register Map
(continued)
Register 15h: RXER Counter ......................................................................................................................................
Register 1bh: Interrupt Control/Status Register ..........................................................................................................
Register 1fh: 100BASE-TX PHY Controller ................................................................................................................
Absolute Maximum Ratings ........................................................................................................................................
Operating Ratings ........................................................................................................................................................
Electrical Characteristics ............................................................................................................................................
Timing Diagrams ..........................................................................................................................................................
Selection of Isolation Transformer ............................................................................................................................
Selection of Reference Crystal ...................................................................................................................................
Package Information ...................................................................................................................................................
April 2005
5
M9999-041405