MAXIM MAX24287

19-5987; Rev 0; 7/11
MAX24287
1Gbps Parallel-to-Serial MII Converter
General Description
The MAX24287 is a flexible, low-cost Ethernet
interface conversion IC. The parallel interface can be
configured for GMII, RGMII, TBI, RTBI, or 10/100 MII,
while the serial interface can be configured for
1.25Gbps SGMII or 1000BASE-X operation. In
SGMII mode, the device interfaces directly to
Ethernet switch ICs, ASIC MACs, and 1000BASE-T
electrical SFP modules. In 1000BASE-X mode, the
device interfaces directly to 1Gbps 1000BASE-X SFP
optical modules. The MAX24287 performs automatic
translation of link speed and duplex autonegotiation
between parallel MII MDIO and the serial interface.
Microprocessor interaction is optional for device
operation. Hardware-configured modes support
SGMII master and 1000BASE-X autonegotiation
without software involvement.
This device is ideal for interfacing single-channel
GMII/MII devices such as microprocessors, FPGAs,
network processors, Ethernet-over-SONET or -PDH
mappers, and TDM-over-packet circuit emulation
devices. The device also provides a convenient
solution to interface such devices with electrical or
optical Ethernet SFP modules.
Applications
Any System with a Need to Interface a Component
with a Parallel MII Interface (GMII, RGMII, TBI RTBI,
10/100 MII) to a Component with an SGMII or
1000BASE-X Interface
Switches and Routers
Telecom Equipment
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX24287ETK+
-40°C to +85°C
68 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Highlighted Features
♦
Bidirectional Wire-Speed Ethernet Interface
Conversion
♦
Can Interface Directly to SFP Modules and
SGMII PHY and Switch ICs
♦
Serial Interface Configurable as 1000BASE-X or
SGMII Revision 1.8 (4-, 6-, or 8-Pin)
♦
Parallel Interface Configurable as GMII, RGMII,
TBI, RTBI, or 10/100 MII
♦
Serial Interface Has Clock and Data Recovery
Block (CDR) and Does Not Require a Clock
Input
♦
Translates Link Speed and Duplex Mode
Negotiation Between MDIO and SGMII PCS
♦
Supports 10/100 MII or RGMII Operation with
SGMII Running at the Same Rate
♦
Configurable for 10/100 MII DTE or DCE
Modes (i.e., Connects to PHY or MAC)
♦
Can Also Be Configured as General-Purpose
1:10 SerDes with Optional Comma Alignment
♦
Supports Synchronous Ethernet by Providing
a 25MHz or 125MHz Recovered Clock and
Accepting a Transmit Clock
♦
Can Provide a 125MHz Clock for the MAC to
Use as GTXCLK
♦
Accepts 10MHz, 12.8MHz, 25MHz or 125MHz
Reference Clock
♦
Can Be Pin-Configured at Reset for Many
Common Usage Scenarios
♦
Optional Software Control Through MDIO
Interface
♦
GPIO Pins Can Be Configured as Clocks,
Status Signals and Interrupt Outputs
♦
1.2V Operation with 3.3V I/O
♦
Small, 8mm x 8mm, 68-Pin TQFN Package
Block Diagram appears on page 7.
Register Map appears on page 41.
Maxim Integrated Products 1
Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple
revisions of any device may be simultaneously available through various sales channels. For information about device
errata, go to: www.maxim-ic.com/errata. For pricing, delivery, and ordering information, please contact Maxim Direct at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
_________________________________________________________________________________________________ MAX24287
Table of Contents
1.
APPLICATION EXAMPLES ............................................................................................................. 6
2.
BLOCK DIAGRAM ........................................................................................................................... 7
3.
DETAILED FEATURES ................................................................................................................... 7
4.
ACRONYMS, ABBREVIATIONS, AND GLOSSARY ...................................................................... 8
5.
PIN DESCRIPTIONS ........................................................................................................................ 8
6.
FUNCTIONAL DESCRIPTION ....................................................................................................... 16
PIN CONFIGURATION DURING RESET ............................................................................................. 16
GENERAL-PURPOSE I/O ................................................................................................................ 17
6.1
6.2
6.2.1
6.3.1
6.3.2
Reset .................................................................................................................................................... 18
Processor Interrupts ............................................................................................................................. 18
MDIO INTERFACE ......................................................................................................................... 19
6.4
6.4.1
6.4.2
MDIO Overview .................................................................................................................................... 19
Examples of MAX24287 and PHY Management Using MDIO ............................................................ 21
SERIAL INTERFACE – 1000BASE-X OR SGMII ............................................................................... 23
PARALLEL INTERFACE – GMII, RGMII, TBI, RTBI, MII .................................................................... 24
6.5
6.6
6.6.1
6.6.2
6.6.3
6.6.4
6.6.5
GMII Mode ........................................................................................................................................... 24
TBI Mode .............................................................................................................................................. 25
RGMII Mode ......................................................................................................................................... 26
RTBI Mode ........................................................................................................................................... 28
MII Mode .............................................................................................................................................. 29
AUTO-NEGOTIATION (AN) .............................................................................................................. 30
6.7
6.7.1
6.7.2
1000BASE-X Auto-Negotiation ............................................................................................................ 30
SGMII Control Information Transfer ..................................................................................................... 32
DATA PATHS ................................................................................................................................. 35
6.8
6.8.1
6.8.2
6.8.3
6.8.4
6.8.5
GMII, RGMII and MII Serial to Parallel Conversion and Decoding ...................................................... 35
GMII, RGMII and MII Parallel to Serial Conversion and Encoding ...................................................... 35
TBI, RTBI Serial to Parallel Conversion and Decoding ....................................................................... 35
TBI Parallel to Serial Conversion and Encoding .................................................................................. 35
Rate Adaption Buffers, Jumbo Packets and Clock Frequency Differences......................................... 35
TIMING PATHS ............................................................................................................................... 36
6.9
6.9.1
6.9.2
6.9.3
6.9.4
6.9.5
6.9.6
6.10.1
6.10.2
6.10.3
6.11
6.12
6.13
RX PLL ................................................................................................................................................. 37
TX PLL ................................................................................................................................................. 37
Input Jitter Tolerance ........................................................................................................................... 37
Output Jitter Generation ....................................................................................................................... 37
TX PLL Jitter Transfer .......................................................................................................................... 37
GPIO Pins as Clock Outputs ................................................................................................................ 38
LOOPBACKS ............................................................................................................................... 38
6.10
7.
Receive Recovered Clock Squelch Criteria ......................................................................................... 18
RESET AND PROCESSOR INTERRUPT ............................................................................................. 18
6.3
Diagnostic Loopback ............................................................................................................................ 38
Terminal Loopback............................................................................................................................... 38
Remote Loopback ................................................................................................................................ 38
DIAGNOSTIC AND TEST FUNCTIONS ............................................................................................ 39
DATA PATH LATENCIES .............................................................................................................. 39
BOARD DESIGN RECOMMENDATIONS .......................................................................................... 39
REGISTER DESCRIPTIONS ......................................................................................................... 41
7.1
7.2
REGISTER MAP ............................................................................................................................. 41
REGISTER DESCRIPTIONS .............................................................................................................. 41
2
_________________________________________________________________________________________________ MAX24287
7.2.1
7.2.2
7.2.3
7.2.4
7.2.5
7.2.6
7.2.7
7.2.8
7.2.9
7.2.10
7.2.11
7.2.12
7.2.13
7.2.14
7.2.15
7.2.16
7.2.17
8.
BMCR ................................................................................................................................................... 42
BMSR ................................................................................................................................................... 43
ID1 and ID2 .......................................................................................................................................... 44
AN_ADV ............................................................................................................................................... 45
AN_RX ................................................................................................................................................. 45
AN_EXP ............................................................................................................................................... 45
EXT_STAT ........................................................................................................................................... 46
JIT_DIAG ............................................................................................................................................. 46
PCSCR ................................................................................................................................................. 47
GMIICR ................................................................................................................................................ 48
CR ........................................................................................................................................................ 49
IR .......................................................................................................................................................... 50
PAGESEL ............................................................................................................................................ 51
ID .......................................................................................................................................................... 52
GPIOCR1 ............................................................................................................................................. 52
GPIOCR2 ............................................................................................................................................. 52
GPIOSR ............................................................................................................................................... 53
JTAG AND BOUNDARY SCAN .................................................................................................... 54
8.1
8.2
8.3
8.4
9.
JTAG DESCRIPTION ...................................................................................................................... 54
JTAG TAP CONTROLLER STATE MACHINE DESCRIPTION ............................................................... 54
JTAG INSTRUCTION REGISTER AND INSTRUCTIONS ........................................................................ 56
JTAG TEST REGISTERS ................................................................................................................ 57
ELECTRICAL CHARACTERISTICS .............................................................................................. 58
9.1
9.2
RECOMMENDED OPERATING CONDITIONS ...................................................................................... 58
DC ELECTRICAL CHARACTERISTICS ............................................................................................... 58
9.2.1
9.2.2
9.3
CMOS/TTL DC Characteristics ............................................................................................................ 59
SGMII/1000BASE-X DC Characteristics.............................................................................................. 59
AC ELECTRICAL CHARACTERISTICS ............................................................................................... 60
9.3.1
9.3.2
9.3.3
9.3.4
9.3.5
9.3.6
9.3.7
REFCLK AC Characteristics ................................................................................................................ 60
SGMII/1000BASE-X Interface Receive AC Characteristics................................................................. 60
SGMII/1000BASE-X Interface Transmit AC Characteristics................................................................ 60
Parallel Interface Receive AC Characteristics ..................................................................................... 61
Parallel Interface Transmit AC Characteristics .................................................................................... 63
MDIO Interface AC Characteristics ...................................................................................................... 65
JTAG Interface AC Characteristics ...................................................................................................... 66
10.
PIN ASSIGNMENTS ...................................................................................................................... 67
11.
PACKAGE AND THERMAL INFORMATION ................................................................................ 68
12.
DATA SHEET REVISION HISTORY .............................................................................................. 69
3
_________________________________________________________________________________________________ MAX24287
List of Figures
Figure 2-1. Block Diagram ........................................................................................................................................... 7
Figure 6-1. MDIO Slave State Machine ..................................................................................................................... 20
Figure 6-2. Management Information Flow Options, Case 1,Tri-Mode PHY ............................................................. 21
Figure 6-3. Management Information Flow Options, Case 2, SGMII Switch Chip .................................................... 21
Figure 6-4. Management Information Flow Options, Case 3, 1000BASE-X Interface .............................................. 22
Figure 6-5. Recommended External Components for High-Speed Serial Interface ................................................. 23
Figure 6-6. Auto-Negotiation with a Link Partner over 1000BASE-X ........................................................................ 31
Figure 6-7. 1000BASE-X Auto-Negotiation tx_Config_Reg and rx_Config_Reg Fields ........................................... 31
Figure 6-8. SGMII Control Information Generation, Reception and Acknowledgement............................................ 33
Figure 6-9. SGMII tx_Config_Reg and rx_Config_Reg Fields .................................................................................. 33
Figure 6-10. Timing Path Diagram............................................................................................................................. 36
Figure 6-11. Recommended REFCLK Oscillator Wiring ........................................................................................... 40
Figure 8-1. JTAG Block Diagram ............................................................................................................................... 54
Figure 8-2. JTAG TAP Controller State Machine ...................................................................................................... 56
Figure 9-1. MII/GMII/RGMII/TBI/RTBI Receive Timing Waveforms .......................................................................... 61
Figure 9-2. MII/GMII/RGMII/TBI/RTBI Transmit Timing Waveforms ......................................................................... 63
Figure 9-3. MDIO Interface Timing ............................................................................................................................ 65
Figure 9-4. JTAG Timing Diagram ............................................................................................................................. 66
4
_________________________________________________________________________________________________ MAX24287
List of Tables
Table 5-1. Pin Type Definitions.................................................................................................................................... 8
Table 5-2. Detailed Pin Descriptions – Global Pins (3 Pins) ....................................................................................... 8
Table 5-3. Detailed Pin Descriptions – MDIO Interface (2 Pins) ................................................................................. 9
Table 5-4. Detailed Pin Descriptions – JTAG Interface (5 pins) .................................................................................. 9
Table 5-5. Detailed Pin Descriptions – GPIO signals (5 dedicated pins, 4 shared pins) ............................................ 9
Table 5-6. Detailed Pin Descriptions – SGMII/1000BASE-X Serial Interface (7 pins) .............................................. 10
Table 5-7. Detailed Pin Descriptions – Parallel Interface (25 pins) ........................................................................... 11
Table 5-8. Detailed Pin Descriptions – Power and Ground Pins (15 pins) ................................................................ 15
Table 6-1. Reset Configuration Pins, 15-Pin Mode (COL=0) .................................................................................... 16
Table 6-2. Parallel Interface Configuration ................................................................................................................ 16
Table 6-3. Reset Configuration Pins, 3-Pin Mode (COL=1) ...................................................................................... 17
Table 6-4. GPO1, GPIO1 and GPIO3 Configuration Options ................................................................................... 17
Table 6-5. GPO2 and GPIO2 Configuration Options................................................................................................. 17
Table 6-6. GPIO4, GPIO5, GPIO6 and GPIO7 Configuration Options ..................................................................... 18
Table 6-7. Parallel Interface Modes ........................................................................................................................... 24
Table 6-8. GMII Parallel Bus Pin Naming .................................................................................................................. 24
Table 6-9. TBI Parallel Bus Pin Naming (Normal Mode} ........................................................................................... 25
Table 6-10. TBI Parallel Bus Pin Naming (One-Clock Mode) ................................................................................... 25
Table 6-11. RGMII Parallel Bus Pin Naming ............................................................................................................. 27
Table 6-12. RTBI Parallel Bus Pin Naming ............................................................................................................... 28
Table 6-13. MII Parallel Bus Pin Naming ................................................................................................................... 29
Table 6-14. AN_ADV 1000BASE-X Auto-Negotiation Ability Advertisement Register (MDIO 4) .............................. 31
Table 6-15. AN_RX 1000BASE-X Auto-negotiation Ability Receive Register (MDIO 5) ........................................... 32
Table 6-16. AN_ADV SGMII Configuration Information Register (MDIO 4) .............................................................. 34
Table 6-17. AN_RX SGMII Configuration Information Receive Register (MDIO 5) .................................................. 34
Table 6-18. Timing Path Muxes – No Loopback ....................................................................................................... 36
Table 6-19. Timing Path Muxes – DLB Loopback ..................................................................................................... 36
Table 6-20. Timing Path Muxes – RLB Loopback ..................................................................................................... 37
Table 6-21. GMII Data Path Latencies ...................................................................................................................... 39
Table 7-1. Register Map ............................................................................................................................................ 41
Table 8-1. JTAG Instruction Codes ........................................................................................................................... 56
Table 8-2. JTAG ID Code .......................................................................................................................................... 57
Table 9-1. Recommended DC Operating Conditions ................................................................................................ 58
Table 9-2. DC Characteristics.................................................................................................................................... 58
Table 9-3. DC Characteristics for Parallel and MDIO Interfaces ............................................................................... 59
Table 9-4. SGMII/1000BASE-X Transmit DC Characteristics ................................................................................... 59
Table 9-5. SGMII/1000BASE-X Receive DC Characteristics .................................................................................... 59
Table 9-6. REFCLK AC Characteristics .................................................................................................................... 60
Table 9-7. 1000BASE-X and SGMII Receive AC Characteristics ............................................................................. 60
Table 9-8. 1000BASE-X and SGMII Receive Jitter Tolerance .................................................................................. 60
Table 9-9. SGMII and 1000BASE-X Transmit AC Characteristics ............................................................................ 60
Table 9-10. 1000BASE-X Transmit Jitter Characteristics.......................................................................................... 60
Table 9-11. GMII and TBI Receive AC Characteristics ............................................................................................. 61
Table 9-12. RGMII-1000 and RTBI Receive AC Characteristics ............................................................................... 62
Table 9-13. RGMII-10/100 Receive AC Characteristics ............................................................................................ 62
Table 9-14. MII–DCE Receive AC Characteristics .................................................................................................... 62
Table 9-15. MII–DTE Receive AC Characteristics .................................................................................................... 63
Table 9-16. GMII, TBI, RGMII-1000 and RTBI Transmit AC Characteristics ............................................................ 63
Table 9-17. RGMII-10/100 Transmit AC Characteristics ........................................................................................... 64
Table 9-18. MII–DCE Transmit AC Characteristics ................................................................................................... 64
Table 9-19. MII–DTE Transmit AC Characteristics ................................................................................................... 64
Table 9-20. MDIO Interface AC Characteristics ........................................................................................................ 65
Table 9-21. JTAG Interface Timing............................................................................................................................ 66
Table 11-1. Package Thermal Properties, Natural Convection ................................................................................. 68
5
_________________________________________________________________________________________________ MAX24287
1. Application Examples
a) Copper Media
<GMII>
<SGMII>
RXD[7:0]
Processor, M
ASIC,
A
FPGA
C
RX_CLK
125 MHz
TXD[7:0]
CDR
MAX
24287
TX_CLK
125 MHz
RD
TD
SGMII
PHY
TCLK
625 MHz
(Optional)
b) Connect Parallel MII Component to SGMII Component
<GMII>
<SGMII>
RXD[7:0]
Processor, M
ASIC,
A
FPGA
C
RX_CLK
125 MHz
TXD[7:0]
CDR
MAX
24287
TX_CLK
125 MHz
Processor, M
ASIC,
A
FPGA
C
c2)
RX_CLK
125 MHz
TXD[7:0]
<SGMII>
CDR
RD
MAX
24287
TX_CLK
125 MHz
TD
<GMII>
<SGMII>
RXD[7:0]
Processor, M
ASIC,
A
FPGA
C
TD
RX_CLK
125 MHz
TXD[7:0]
M Ethernet
A Switch
Chip
C
TCLK
625 MHz
(Optional)
c1) Long PCB Trace Card-to-Card
<GMII>
RXD[7:0]
RD
CDR
RD
MAX
24287
TX_CLK
125 MHz
TD
C
o
n
n
e
c
t
o
r
100 Ohm
PCB Trace
C
o
n
n
e
c
t
o
r
100 Ohm
PCB Trace
100 Ohm
PCB Trace
C
o
n
n
e
c
t
o
r
<SGMII>
<GMII>
TD
TXD[7:0]
MAX
24287
RD
CDR
TXCLK
125 MHz
RXD[7:0]
GMII
PHY
RXCLK
125 MHz
<SGMII>
100 Ohm
PCB Trace
C
o
n
n
e
c
t
o
r
TD
SGMII
PHY
RD
d) Fiber Module
1000BASE-SX/LX
<GMII>
RXD[7:0]
Processor, M
ASIC,
A
FPGA
C
RX_CLK
125 MHz
TXD[7:0]
TX_CLK
125 MHz
CDR
RD
MAX
24287
Optical
Module
TD
6
_________________________________________________________________________________________________ MAX24287
2. Block Diagram
Figure 2-1. Block Diagram
MAX24287
TXD[7:0]
GTXCLK
TXCLK
TX_EN
TX_ER
Transmit
GMII
RGMII
TBI
RTBI
MII
D
D
C
C
PCS
Decoder
(10b/8b)
Rate
Adaption
Buffer
RD[9:0]
RD
125MHz
1.25GHz
DeSerializer
AutoNegotiate
Receive
CDR
RDP
RDN
TLB Loopback
Receive
GMII
RGMII
TBI
RTBI
MII
DLB Loopback
RLB Loopback
RXD[7:0]
RXCLK
RX_DV
RX_ER
COL
CRS
TDP
D
C
Rate
Adaption
Buffer
PCS
Encoder
(8b/10b)
D
C
TD[9:0]
TD
Serializer
125MHz
625MHz
Transmit
Driver
TDN
TCLKP
TCLKN
625MHz
125MHz, 62.5MHz, 25MHz, 2.5MHz
Control
and
Status
125MHz
TX PLL
REFCLK
GPIO7
GPIO6
GPIO5
GPIO4
GPIO3
GPIO2
GPIO1
GPO1
GPIO Control
GPO2
MDIO
MDC
RST_N
ALOS
3. Detailed Features
General Features
•
•
•
•
High-speed MDIO interface (12.5MHz slave only) with optional preamble suppression
Can be pin-configured at reset for many common usage scenarios
Operates from a 10, 12.8, 20, 25, or 125MHz reference clock
Optional 125MHz output clock for MAC to use as GTXCLK
Parallel-Serial MII Conversion Features
•
•
•
•
•
•
•
•
•
•
Bidirectional wire-speed interface conversion
Serial Interface: 1000BASE-X or SGMII revision 1.8 (4-, 6-, or 8-Pin)
Parallel Interface: GMII, RGMII (10, 100 and 1000Mbps), TBI, RTBI or 10/100 MII (DTE or DCE)
8-pin source-clocked SGMII mode
4-pin 1000BASE-X SerDes mode to interface with optical modules
Connects processors with parallel MII interfaces to 1000BASE-X SFP optical modules
Connects processors with parallel MII interfaces to PHY or switch ICs with SGMII interfaces
Interface conversion is transparent to MAC layer and higher layers
Translates link speed and duplex mode between GMII/MII MDIO and SGMII PCS
Configurable for 10/100 MII DTE or DCE Modes (i.e., connects to PHY or MAC)
Synchronous Ethernet Features
•
•
Receive path bit clock can be output on a GPIO pin to line-time the system from the Ethernet port
Transmit path can be frequency-locked to a system clock signal connected to the REFCLK pin
7
_________________________________________________________________________________________________ MAX24287
4. Acronyms, Abbreviations, and Glossary
•
•
•
•
•
DCE
DDR
DTE
PCB
PHY
Data Communication Equipment
Dual Data Rate (data driven and latched on both clock edges)
Data Terminating Equipment
Printed Circuit Board
Physical. Refers to either a transceiver device or a protocol layer
•
•
•
•
Ingress
Egress
Receive
Transmit
The serial (SGMII) to parallel (GMII) direction
The parallel (GMII) to serial (SGMII) direction
The serial (SGMII) to parallel (GMII) direction
The parallel (GMII) to serial (SGMII) direction
5. Pin Descriptions
Note that some pins have different pin names and functions under different configurations.
Table 5-1. Pin Type Definitions
Type
Definition
I
Input
Idiff
Input, differential
Ipu
Input, with pullup
Ipd
Input, with pulldown
IO
Bidirectional
IOr
Bidirectional, sampled at reset
IOz
Bidirectional, can go high impedance
O
Output
Odiff
Output, differential (CML)
Oz
Output, can go high impedance
Table 5-2. Detailed Pin Descriptions – Global Pins (2 Pins)
Pin Name
PIN # Type
Pin Description
RST_N
67
I
Reset (active low, asynchronous)
This signal resets all logic, state machines and registers in the device. Pin states
are sampled and used to set the default values of several register fields as
described in 6.1. RST_N should be held low for at least 100µs. See section
6.3.1.
REFCLK
68
I
Reference Clock
This signal is the reference clock for the device. The frequency can be 10MHz,
12.8MHz, 25MHz or 125MHz ± 100 ppm. At reset the frequency is specified
using the RXD[3:2] pins (see section 6.1). The REFCLK signal is the input clock
to the TX PLL. See section 6.9.
8
_________________________________________________________________________________________________ MAX24287
Table 5-3. Detailed Pin Descriptions – MDIO Interface (2 Pins)
Pin Name
PIN # Type
Pin Description
MDC
41
I
MDIO Clock.
MDC is the clock signal of the 2-wire MDIO interface. It can be any frequency up
to 12.5MHz. See section 6.4.
MDIO
42
IOz
MDIO Data.
This is the bidirectional, half-duplex data signal of the MDIO interface. It is
sampled and updated on positive edges of MDC. IEEE 802.3 requires a 2kΩ±5%
pulldown resistor on this signal at the MAC. See section 6.4.
Table 5-4. Detailed Pin Descriptions – JTAG Interface (5 pins)
Pin Name
PIN # Type
Pin Description
JTRST_N
43
I
JTAG Test Reset (active low).
Asynchronously resets the test access port (TAP) controller. If not used, connect
to DVDD33 or DVSS. See section 8.
JTCLK
21
I
JTAG Test Clock.
This clock signal can be any frequency up to 10MHz. JTDI and JTMS are
sampled on the rising edge of JTCLK, and JTDO is updated on the falling edge
of JTCLK. If not used, connect to DVDD33 or DVSS. See section 8.
JTMS
22
I
JTAG Test Mode Select.
Sampled on the rising edge of JTCLK. Used to place the port into the various
defined IEEE 1149.1 states. If not used, connect to DVDD33. See section 8.
JTDI
23
I
JTAG Test Data Input.
Test instructions and data are clocked in on this pin on the rising edge of JTCLK.
If not used, connect to DVDD33. See section 8.
JTDO
44
Oz
JTAG Test Data Output.
Test instructions and data are clocked out on this pin on the falling edge of
JTCLK. If not used leave unconnected. See section 8.
Table 5-5. Detailed Pin Descriptions – GPIO signals (5 dedicated pins, 4 shared pins)
Pin Name
PIN # Type
Pin Description
GPO1
24
IOr
General Purpose Output 1.
After reset, this pin can either be high impedance (TBI or RTBI mode) or an
output that indicates link status, 0=link down, 1=link up.
The function can be changed after reset. See section 6.2.
GPO2
25
IOr
General Purpose Output 2.
After reset, this pin can either be high impedance (TBI or RTBI mode) or an
output that indicates CRS (carrier sense).
The function can be changed after reset. See section 6.2.
GPIO1
61
IOz
General Purpose Input or Output 1.
After reset this pin can be either high impedance or generating a 125MHz
clock signal.
GPO1=0 at reset: After reset, GPIO1 is high impedance.
GPO1=1 at reset: After reset, GPIO1 is 125MHz clock out
The function can be changed after reset. See section 6.2.
GPIO2
60
IOz
General Purpose Input or Output 2.
After reset this pin is high impedance. The function can be changed after
reset. See section 6.2.
GPIO3
59
IOz
General Purpose Input or Output 3.
After reset this pin is high impedance. The function can be changed after
reset. See section 6.2.
9
_________________________________________________________________________________________________ MAX24287
Pin Name
GPIO4/TXD[4]
PIN #
52
Type
IOz
GPIO5/TXD[5]
53
IOz
GPIO6/TXD[6]
54
IOz
GPIO7/TXD[7]
55
IOz
Pin Description
General Purpose Input or Output 4.
Available for use as a GPIO pin when the parallel interface is configured for
MII, RGMII or RTBI modes.
After reset this pin is high impedance. The function can be changed after
reset. See section 6.2.
General Purpose Input or Output 5.
Available for use as a GPIO pin when the parallel interface is configured for
MII, RGMII or RTBI modes.
After reset this pin is high impedance. The function can be changed after
reset. See section 6.2.
General Purpose Input or Output 6.
Available for use as a GPIO pin when the parallel interface is configured for
MII, RGMII or RTBI modes.
After reset this pin is high impedance. The function can be changed after
reset. See section 6.2.
General Purpose Input or Output 7.
Available for use as a GPIO pin when the parallel interface is configured for
MII, RGMII or RTBI modes.
After reset this pin is high impedance. The function can be changed after
reset. See section 6.2.
Table 5-6. Detailed Pin Descriptions – SGMII/1000BASE-X Serial Interface (7 pins)
Pin Name
PIN # Type
Pin Description
TDP,
9
Odiff Transmit Data Output
TDN
8
These pins form a differential CML output for the 1.25Gbaud SGMII transmit
signal to a neighboring 1000BASE-X optical module (SFP, etc.) or PHY with
SGMII interface. See section 6.5.
TCLKP,
6
Odiff Transmit Clock Output
TCLKN
5
These pins form a differential CML output for an optional 625MHz clock for
the SGMII transmit signal on TDP/TDN. This output is disabled at reset but is
enabled by setting CR.TCLK_EN=1. See section 6.5.
RDP,
13
Idiff
Receive Data Input
RDN
14
These pins form a differential input for the 1.25Gbaud SGMII receive signal
from a neighboring 1000BASE-X optical module (SFP, etc.) or PHY with
SGMII interface. A receive clock signal is not necessary because the device
uses a built-in CDR to recover the receive clock from the signal on RDP/RDN.
See section 6.5.
ALOS
19
I
Analog Loss of Signal
This pin receives analog loss-of-signal from a neighboring optical transceiver
module. If the optical module does not have an ALOS output, this pin should
be connected to DVSS for proper operation. See section 6.5.
0 = ALOS not detected or not required, normal operation
1 = ALOS detected, loss of signal
10
_________________________________________________________________________________________________ MAX24287
Table 5-7. Detailed Pin Descriptions – Parallel Interface (25 pins)
Pin Name
RXCLK
PIN #
Type
40
IO
Pin Description
Receive Clock
In all modes the frequency tolerance is ± 100 ppm.
GMII Mode: RXCLK is the 125MHz receive clock.
RGMII Modes: RXCLK is the 125MHz (RGMII-1000), 25MHz (RGMII-100) or
2.5MHz (RGMII-10) receive clock (DDR).
TBI Mode: In normal TBI mode (GMIICR.TBI_RATE=1 or RX_DV=1 at
reset), RXCLK is the 62.5MHz receive clock for odd code groups and
TXCLK/RCXCLK1 is the 62.5MHz receive clock for even code groups.
In one-clock TBI mode (GMIICR.TBI_RATE=0 or RX_DV=0 at reset),
RXCLK is the 125MHz receive clock.
RTBI Mode: RXCLK is the 125MHz receive clock (DDR).
RXD[0]
38
IOr
RXD[1]
37
IOr
RXD[2]
36
IOr
RXD[3]
35
IOr
RXD[4]
34
IOr
RXD[5]
33
IOr
RXD[6]
32
IOr
RXD[7]
31
IOr
MII Mode: RXCLK is the 25MHz (100Mbps MII) or 2.5MHz (10Mbps MII)
receive clock.
In DTE mode (DCE_DTE)=1, RXCLK is an input.
In DCE mode (DCE_DTE)=0, RXCLK is an output.
Receive Data Outputs
During reset these pins are configuration inputs. See section 6.1. After reset
they are driven as outputs.
GMII Mode: receive_data[7:0] is output on RXD[7:0] on the rising edge of
RXCLK.
MII, RGMII-10 and RGMII-100 Modes: receive_data[3:0] is output on
RXD[3:0] on the rising edge of RXCLK. RXD[7:4] are high impedance.
RGMII-1000 Mode: receive_data[3:0] is output on RXD[3:0] on the rising edge
of RXCLK, and receive_data[7:4] is output on the falling edge of RXCLK.
RXD[7:4] are high impedance.
TBI Mode: In normal TBI mode (GMIICR.TBI_RATE=1 or RX_DV=1 at reset),
receive_data[7:0] is output on RXD[7:0], receive_data[8] is output on RX_DV,
and receive_data[9] is output on RX_ER on the rising edge of RXCLK and the
rising edge of RXCLK1 (both 62.5MHz, 180 degrees out of phase).
In one-clock TBI mode (GMIICR.TBI_RATE=0 or RX_DV=0 at reset), these
same signals are output on the rising edge of RXCLK (125MHz).
RTBI Mode: Receive_data[3:0] is output on RXD[3:0] and
Receive_data[4] is output on RX_DV on the rising edge of RXCLK.
Receive_data[8:5] is output on RXD[3:0] and receive_data[9] is output on
RX_DV on the falling edge of RXCLK. RXD[7:4] are high impedance.
11
_________________________________________________________________________________________________ MAX24287
Pin Name
RX_DV
PIN #
Type
29
IOr
Pin Description
Receive Data Valid
During reset this pin is a configuration input. See section 6.1. After reset it is
driven as an output.
MII Mode and GMII Mode: RX_DV is output on the rising edge of RXCLK.
RGMII Modes: The RX_CTL signal is output on RX_DV on both edges of
RXCLK.
TBI Mode: In normal TBI mode (GMIICR.TBI_RATE=1 or RX_DV=1 at reset),
receive_data[8] is output on RX_DV on the rising edge of RXCLK and the
rising edge of RXCLK1 (both 62.5MHz, 180 degrees out of phase).
In one-clock TBI mode (GMIICR.TBI_RATE=0 or RX_DV=0 at reset),
receive_data[8] is output on RX_DV on the rising edge of RXCLK (125MHz).
RX_ER
28
IOr
RTBI Mode: Receive_data[4} is output on RX_DV on the rising edge of
RXCLK. Receive_data[9] is output on RX_DV on the falling edge of RXCLK.
Receive Error
During reset this pin is a configuration input. See section 6.1. After reset it is
driven as an output.
MII Mode and GMII Mode: RX_ER is output on the rising edge of RXCLK.
RGMII Mode and RTBI Mode: RX_ER pin is high impedance.
COL
27
IOr
TBI Mode: In normal TBI mode (GMIICR.TBI_RATE=1 or RX_DV=1 at reset),
receive_data[9] is output on RX_ER on the rising edge of RXCLK and the
rising edge of RXCLK1 (both 62.5MHz, 180 degrees out of phase).
In one-clock TBI mode (GMIICR.TBI_RATE=0 or RX_DV=0 at reset),
receive_data[9] is output on the rising edge of RXCLK (125MHz).
Collision Detect
During reset this pin is a configuration input. See section 6.1. After reset it is
driven as an output.
MII Mode. GMII Mode and RGMII Modes: COL indicates that a Tx/Rx collision
is occurring. It is meaningful only in half duplex operation. It is asynchronous
to any of the clocks. COL is driven low at all times when BMCR.DLB=1 and
BMCR.COL_TEST=0. When BMCR.DLB=1 and BMCR.COL_TEST=1, COL
behaves as described in the COL_TEST bit description.
1 = Collision is occurring
0 = Collision is not occurring
TBI Mode and RTBI Mode: This pin is high impedance.
12
_________________________________________________________________________________________________ MAX24287
Pin Name
PIN #
Type
CRS/COMMA
26
IOr
Pin Description
Carrier Sense / Comma Detect
During reset this pin is a configuration input. See section 6.1. After reset it is
driven as an output.
MII Mode. GMII Mode and RGMII Modes: CRS is asserted by the device
when either the transmit data path or the receive data path is active. This
signal is asynchronous to any of the clocks.
TXCLK/
RXCLK1
46
IO
TBI Mode and RTBI Mode: COMMA is asserted by the device when a comma
pattern is detected in the receive data stream. In normal TBI mode
(GMIICR.TBI_RATE=1 or RX_DV=1 at reset), COMMA is updated on the
rising edge of RXCLK and the rising edge of RXCLK1 (both 62.5MHz, 180
degrees out of phase). In one-clock TBI mode (GMIICR.TBI_RATE=0 or
RX_DV=0 at reset) and RTBI mode, COMMA is updated on the rising edge of
RXCLK (125MHz).
MII Transmit Clock
When TXCLK is an input, frequency tolerance is ±100ppm.
MII Mode: TXCLK is the 25MHz (100Mbps MII) or 2.5MHz 10Mbps MII)
transmit clock.
In DTE mode (DCE_DTE)=1, TXCLK is an input.
In DCE mode (DCE_DTE)=0, TXCLK is an output.
GMII Mode, RGMII Mode and RTBI Mode: TXCLK can output a 125MHz
clock for use by neighboring components (e.g. a MAC) when
GMIICR.TXCLK_EN=1 (or TXCLK=1 at reset).
GTXCLK
66
I
TBI Mode: In normal TBI mode (GMIICR.TBI_RATE=1 or RX_DV=1 at
reset), this pin becomes the 62.5MHz RXCLK1 output for even code groups.
In one-clock TBI mode (GMIICR.TBI_RATE=0 or RX_DV=0 at reset), TXCLK
can output a 125MHz clock for use by neighboring components (e.g. a MAC)
when GMIICR.TXCLK_EN=1 (or TXCLK=1 at reset).
GMII/RGMII Transmit Clock
In all modes the frequency tolerance is ± 100ppm.
GMII Mode: GTXCLK is the 125MHz transmit clock.
RGMII Modes: GTXCLK is the 125MHz (RGMII-1000), 25MHz (RGMII-100)
or 2.5MHz (RGMII-10) transmit clock (DDR).
TBI Mode: GTXCLK is the 125MHz transmit clock.
RTBI Mode: GTXCLK is the 125MHz transmit clock (DDR).
MII Mode: This pin is not used and should be pulled low. See the TXCLK pin
description.
13
_________________________________________________________________________________________________ MAX24287
Pin Name
PIN #
Type
TXD[0]
48
I
TXD[1]
49
I
TXD[2]
50
I
TXD[3]
51
I
TXD[4]/GPIO4
52
IOz
TXD[5]/GPIO5
53
IOz
TXD[6]/GPIO6
54
IOz
TXD[7]/GPIO7
55
IOz
Pin Description
Transmit Data Inputs
Depending on the parallel MII interface mode, four or eight of these pins are
used to accept transmit data from a neighboring component.
GMII Mode: The rising edge of GTXCLK latches transmit_data[7:0] from
TXD[7:0].
MII, RGMII-10 and RGMII-100 Modes: The rising edge of TXCLK (MII) or
GTXCLK (RGMII) latches transmit_data[3:0] from TXD[3:0].
TXD[7:4] become GPIO7 – GPIO4.
RGMII-1000 Mode: The rising edge of GTXCLK latches transmit_data[3:0]
from TXD[3:0]. The falling edge of GTXCLK latches transmit_data[7:4] from
TXD[3:0].
TXD[7:4] become GPIO7 – GPIO4.
TBI Mode: The rising edge of GTXCLK latches transmit_data[7:0] from
TXD[7:0], transmit_data[8] from TX_EN and transmit_data[9] from TX_ER.
TX_EN
57
I
RTBI Mode: The rising edge of GTXCLK latches transmit_data[3:0] from
TXD[3:0] and transmit_data[4] from TX_EN. The falling edge of GTXCLK
latches transmit_data[8:5] from TXD[3:0] and transmit data[9] from TX_EN.
TXD[7:4] become GPIO7 – GPIO4.
Transmit Enable
MII Mode and GMII Mode: The rising edge of TXCLK (MII) or GTXCLK (GMII)
latches the TX_EN signal from this pin.
RGMII Modes: Both edges of GTXCLK latch the TX_CTL signal from this pin.
TBI Mode: The rising edge of GTXCLK latches transmit_data[7:0] from
TXD[7:0], transmit_data[8] from TX_EN and transmit_data[9] from TX_ER.
TX_ER
58
I
RTBI Mode: The rising edge of GTXCLK latches transmit_data[3:0] from
TXD[3:0] and transmit_data[4] from TX_EN. The falling edge of GTXCLK
latches transmit_data[8:5] from TXD[3:0] and transmit data[9] from TX_EN.
Transmit Error
MII Mode and GMII Mode: The rising edge of TXCLK (MII) or GTXCLK (GMII)
latches the TX_ER signal from this pin.
RGMII Modes: This pin is not used.
TBI Mode: The rising edge of GTXCLK latches transmit_data[7:0] from
TXD[7:0], transmit_data[8] from TX_EN and transmit_data[9] from TX_ER.
RTBI Mode: This pin is not used.
14
_________________________________________________________________________________________________ MAX24287
Table 5-8. Detailed Pin Descriptions – Power and Ground Pins (17 pins)
Pin Name
PIN #
Pin Description
DVDD12
30, 56
Digital Power Supply, 1.2V (2 pins)
DVDD33
20, 39, 65 Digital Power Supply, 3.3V
DVSS
47
Return for DVDD12 and DVDD33
RVDD12
16
1.25G Receiver Analog Power Supply, 1.2V
RVDD33
12
1.25G Receiver Analog Power Supply, 3.3V
RVSS
15
Return for RVDD12 and RVDD33
TVDD12
11
1.25G Transmitter Analog Power Supply, 1.2V
TVDD33
7
1.25G Transmitter Analog Power Supply, 3.3V
TVSS
10
Return for TVDD12 and TVDD33
CVDD12
3
TX PLL Analog Power Supply, 1.2V
CVDD33
2
TX PLL Analog Power Supply, 3.3V
CVSS
4
Return for CVDD12 and CVDD33
GVDD12
18
Analog Power Supply, 1.2V
GVSS
1
Return for GVDD12.
Exposed pad (die paddle). Connect to ground plane. EP also functions as a
Exposed Pad
EP
heatsink. Solder to the circuit-board ground plane to maximize thermal
dissipation.
15
_________________________________________________________________________________________________ MAX24287
6. Functional Description
6.1
Pin Configuration During Reset
The MAX24287 initial configuration is determined by pins that are sampled at reset. The values on these pins are
used to set the reset values of several register bits.
The pins that are sampled at reset to pin-configure the device are listed described in Table 6-1. During reset these
pins are high-impedance inputs and require 10kΩ pullup or pulldown resistors to set pin-configuration values. After
reset, the pins can become outputs if configured to do so and operate as configured. There are two pin
configuration modes: 15-pin mode and 3-pin mode.
In 15-pin mode (COL=0 during reset, see Table 6-1) all major settings associated with the PCS block are
configurable. In addition, the input reference clock frequency on the REFCLK pin is configured during reset using
the RXD[3:2] pins.
Table 6-1. Reset Configuration Pins, 15-Pin Mode (COL=0)
Pin
CRS
Function
Double Date Rate
Register Bit Affected
GMIICR:DDR=CRS
GPO2
10/100 MII: DTE or
DCE
10/100 MII: GMIICR:DTE_DCE
Other: Serial Interface
Other: PCSCR:BASEX
GPO1
GPIO1 Configuration
GPIOCR1.GPIO1_SEL[2]
RXD[1:0]
Parallel Interface
Speed
GMIICR:SPD[1:0]
RXD[3:2]
REFCLK Frequency
None
RXD[7:4]
MDIO PHYAD[3:0].
RX_ER
MDIO PHYAD[4].
Internal MDIO PHYAD register
(device address on MDIO bus).
TBI Mode
GMIICR:TBI_RATE
Other: Auto-negotiation
BMCR:AN_EN
TXCLK Enable
GMIICR:TXCLK_EN
RX_DV
TXCLK
Table 6-2. Parallel Interface Configuration
SPD[1] SPD[0]
Speed
DDR=0
0
0
10Mbps
MII
0
1
100Mbps
MII
1
0
1000Mbps
GMII
1
1
1000Mbps
TBI
Notes
See Table 6-2.
0=DCE, 1=DTE
(serial interface is configured for
SGMII mode, PCSCR:BASEX=0)
0=SGMII, 1=1000BASE=X
0=high impedance
1=125MHz from TX PLL
See Table 6-2.
00=10MHz, 01=12.8MHz,
10=25MHz, 11=125MHz
Note: PHYAD[4:0]=11111
enables factory test mode. Do not
use.
0=one-clock mode (125MHz)
1=normal mode (62.5MHz x 2)
0=Disable, 1=Enable
0=high impedance
1=125MHz from TX PLL
Ignored in MII mode and TBI with
two 62.5MHz Rx clocks
DDR=1
RGMII-10
RGMII-100
RGMII-1000
RTBI
In 3-pin mode (COL=1 during reset, see Table 6-3) the device is configured for a 1000Mbps RGMII or GMII parallel
interface. This mode is targeted to the application of connecting an ASIC, FPGA or processor with an RGMII or
GMII interface to a switch device with an SGMII interface or to a 1000BASE-X optical interface. In 3-pin mode, the
REFCLK pin is configured for 25MHz, the PHY address is set to 0x04, 1000BASE-X auto-negotiation (or automatic
transmission of SGMII control information) is enabled, TXCLK is configured to output a 125MHz clock, and the
TCLKP/TCLKN differential pair is disabled.
16
_________________________________________________________________________________________________ MAX24287
Table 6-3. Reset Configuration Pins, 3-Pin Mode (COL=1)
Pin
CRS
GPO2
Function
Double Date Rate
Serial Interface
Register Bit Affected
GMIICR:DDR=CRS
PCSCR:BASEX
Notes
0=GMII, 1=RGMII
0=SGMII, 1=1000BASE=X
Note: In 3-pin mode register fields are automatically set as follows: REFCLK clock rate to 25MHz, GMIICR:SPD[1:0]=10, MDIO PHYAD is set to
0x04, BMCR:AN_EN=1, GMIICR:TXCLK_EN=1, GPIOCR1=0 and GPIOCR2=0. All other registers are reset to normal defaults listed in the
register descriptions.
6.2
General-Purpose I/O
The MAX24287 has two general-purpose output pins, GPO1, GPO2, and seven general-purpose input/output pins,
GPIO1 through GPIO7. Each pin can be configured to drive low or high or be in a high-impedance state. Other
uses for the GPO and GPIO pins are listed in Table 6-4 through Table 6-6. The GPO and GPIO pins are each
configured using a GPxx_SEL field in registers GPIOCR1 or GPIOCR2 with values as indicated in the tables
below.
When a GPIO pin is configured as high impedance it can be used as an input. The real-time state of GPIOx can be
read from GPIOSR.GPIOx. In addition, a latched status bit GPIOSR.GPIOxL is available for each GPIO pin. This
latched status bit is set when the transition specified by GPIOCR2.GPIO13_LSC (for GPIO1 through GPIO3) or by
GPIOCR2.GPIO47_LSC (for GPIO4 through GPIO7) occurs on the pin.
Note that GPIO4 through GPIO7 are alternate pin functions to TXD[7:4] and therefore are only available when the
parallel MII is configured for MII, RGMII or RTBI.
Table 6-4. GPO1, GPIO1 and GPIO3 Configuration Options
GPxx_SEL
Description
000
High impedance, not driven, can be an used as an input
001
Drive logic 0
010
Drive logic 1
011
Interrupt output, active low. GPO1 drives low and high, GPIO1 and GPIO3 are open-drain.
100
Output 125MHz from the TX PLL
101
Output 25MHz or 125MHz from receive clock recovery PLL. Not squelched. Frequency specified
by CR.RCFREQ.
110
Output real-time link status, 0=link down, 1=link up
111
reserved value, do not use
Table 6-5. GPO2 and GPIO2 Configuration Options
GPxx_SEL
Description
000
High impedance, not driven, can be an used as an input
001
Drive logic 0
010
Drive logic 1
011
reserved value, do not use
100
Output 125MHz from TX PLL
101
Output 25MHz or 125MHz from receive clock recovery PLL. The frequency is specified by
CR.RCFREQ. Signal is automatically squelched (driven low) when CR.RCSQL=1 and any of
several conditions occur. See section 6.2.1.
110
Output CRS (carrier sense) status
111
reserved value, do not use
17
_________________________________________________________________________________________________ MAX24287
Table 6-6. GPIO4, GPIO5, GPIO6 and GPIO7 Configuration Options
GPxx_SEL
Description
000
High impedance, not driven, can be an used as an input
001
Drive logic 0
010
Drive logic 1
011
reserved value, do not use
100
Output 125MHz from TX PLL
101
Output 25MHz or 125MHz from receive clock recovery PLL. The frequency is specified by
CR.RCFREQ. Signal is automatically squelched (driven low) when CR.RCSQL=1 and any of
several conditions occur. See section 6.2.1.
110
reserved value, do not use
111
reserved value, do not use
6.2.1 Receive Recovered Clock Squelch Criteria
A 25MHz or 125MHz clock from the receive clock recovery PLL can be output on any of GPO2, GPIO2 and
GPIO4-7. When CR.RCSQL=1, this clock is squelched (driven low) when any of the following conditions occur:
•
•
•
•
IR.ALOS=1 (analog loss-of-signal occurred)
IR.RLOS=1 (CDR loss-of-signal occurred))
IR.RLOL=1 (CDR PLL loss-of-lock occurred)
IR.LINK_ST=0 (auto-negotiation link down occurred, latched low)
Since each of these criteria is a latched status bit, the output clock signal remains squelched until all of these
latched status bits go inactive (as described in section 7.2).
6.3
Reset and Processor Interrupt
6.3.1 Reset
The following reset functions are available in the device:
1. Hardware reset pin (RST_N): This pin asynchronously resets all logic, state machines and registers in the
device except the JTAG logic. When the RST_N pin is low, all internal registers are reset to their default
values. Pin states are sampled and used to set the default values of several register fields as described in
section 6.1. RST_N should be asserted for at least 100µs.
2. Global reset bit, GPIOCR1.RST: Setting this bit is equivalent to asserting the RST_N pin. This bit is selfclearing.
3. Datapath reset bit, BMCR.DP_RST. This bit resets the entire datapath from parallel MII interface through PCS
encoder and decoder. It also resets the deserializer. It does not reset any registers, GPIO logic, or the TX PLL.
The DP_RST bit is self-clearing.
4. JTAG reset pin JTRST_N. This pin resets the JTAG logic. See section 8 for details about JTAG operation.
6.3.2 Processor Interrupts
Any of pins GPO1, GPIO1 and GPIO3 can be configured as an active low interrupt output by setting the
appropriate field in GPIOCR1 to 011. GPO1 drives high and low while GPIO1 and GPIO3 are open-drain and
require pullup resistors.
Status bits than can cause an interrupt are located in the IR register. The corresponding interrupt enable bits are
also located in the IR register. The PAGESEL register has a top-level IR status bit to indicate the presence of
18
_________________________________________________________________________________________________ MAX24287
active interrupt sources. The PAGESEL register is available on all pages through the MDIO interface, allowing the
interrupt routine to read the register without changing the MDIO page.
6.4
MDIO Interface
6.4.1 MDIO Overview
The MAX24287's MDIO interface is compliant to IEEE 802.3 clause 22. MAX24287 always behaves as a PHY on
the MDIO bus. Because MAX24287 is not a complete PHY but rather a device that sits between a MAC and a
PHY, it implements only a subset of the registers and register fields specified in 802.3 clause 22 as shown in the
table below.
MDIO
Address
0
1
2, 3
4
5
6
15
MAX24287 Name
802.3 Name
Control
Status
PHY Identifier
Auto-Negotiation Advertisement
Auto-Negotiation Link Partner Base Page Ability
Auto-Negotiation Expansion
Extended Status
BMCR
BMSR
ID1, ID2
AN_ADV
AN_RX
AN_EXP
EXT_STAT
The MDIO consists of a bidirectional, half-duplex serial data signal (MDIO) and a ≤12.5MHz clock signal (MDC)
driven by a bus master, usually a MAC. The format of management frames transmitted over the MDIO interface is
shown below (see IEEE 802.3 clause 22.2.4.5 for more information). MDIO DC electrical characteristics are listed
in section 9.2.1. AC electrical characteristics are listed in section 9.3.6. The MAX24287's MDIO slave state
machine is shown in Figure 6-1.
READ Command
WRITE Command
PRE
32 ‘1’s
32 ‘1’s
ST
01
01
Management Frame Fields
OP PHYAD REGAD TA
10 AAAAA RRRRR Z0
01 AAAAA RRRRR 10
DATA
16-bit
16-bit
IDLE
Z
Z
The transmission and reception bit order is MSB first for the PHYAD, REGAD and DATA fields
MAX24287 supports preamble suppression. This allows quicker bursts of read and write transfers to occur by
shortening the minimum transfer cycle time from 65 clock periods to 33 clock periods. There must be at least a
32-bit preamble on the first transfer after reset, but on subsequent transfers the preamble can be suppressed or
shortened. When the preamble is completely suppressed the 0 in the ST symbol follows the single IDLE Z, which is
one clock period duration.
Like any MDIO slave, MAX24287 only performs the read or write operation specified if the PHYAD bits of the MDIO
command match the device PHY address. The device PHY address is latched during device reset from the
RXD[7:4] and RX_ER pins. See section 6.1.
The MAX24287 does not support the 802.3 clause 45 MDIO extensions. Management frames with ST bits other
than 01 or OP bits other than 01 or 10 are ignored and put the device in a state where it ignores the MDIO traffic
until it sees a full preamble (32 ones). If Clause 45 ICs and the MAX24287 are connected to the same MDIO
management interface, the station management entity must put a full preamble on the bus after communicating
with clause 45 ICs before communicating with the MAX24287.
19
_________________________________________________________________________________________________ MAX24287
Figure 6-1. MDIO Slave State Machine
HW RESET
PREAMBLE
INIT
MDIO=Z
32 consecutive 1s
PREAMBLE
/ IDLE
MDIO=Z
0
0
1
ST 2nd bit
MDIO=Z
1
00 or 11
OP 2 bits
MDIO=Z
24 clocks
01 or 10
PHYAD 5 bits
MDIO=Z
No match
match
REGAD 5 bits
MDIO=Z
OP=10 (read)
NOT PHY
MDIO=Z
19 clocks
No match
NOT REG
MDIO=Z
OP=01 (write)
TA-Z
MDIO=Z
TA 2 bits
MDIO=Z
TA-0
MDIO=0
DATA 16 bits
MDIO=Z
16 clocks
DATA 16 bits
MDIO=D[15:0]
16 clocks
IDLE
MDIO=Z
20
_________________________________________________________________________________________________ MAX24287
6.4.2 Examples of MAX24287 and PHY Management Using MDIO
The MDIO interface is typically provided by the MAC function within a neighboring processor, ASIC or FPGA
component. It can be used to configure the registers in the MAX24287 and/or the registers in a PHY or switch chip
connected to the MAX24287 via the SGMII interface.
Case 1 in Figure 6-2 shows a typical application where the MAX24287 connects a MAC with a 3-speed RGMII
interface to a 3-speed PHY with an SGMII interface. Through the MDIO interface, system software configures the
MAX24287 and optionally the PHY. (The PHY may not need to be configured if it is operating in a hardware-only
auto-negotiation 1000BASE-T mode). After initial configuration and after the PHY auto-negotiates link details with
its 1000BASE-T link partner, the speed and mode are transferred to the MAX24287 over the SGMII interface as
specified in the SGMII specification and are available in the MAX24287 AN_RX register. The processor reads this
information and configures the MAC and the MAX24287 to match the mode the PHY is in.
Figure 6-2. Management Information Flow Options, Case 1,Tri-Mode PHY
RGMII
Transfer Speed Control
Acknowledge Speed contol
SGMII
RXD[3:0]
MAC
(RGMII)
RX_CLK
2.5/25/125MHz
TXD[3:0]
CDR
MAX24287
RD
TD
TCLK
625 MHz
GTX_CLK
2.5/25/125MHz
10BASE-T
100BASE-T
1000BASE-T
PHY
MDIO
Case 2 in Figure 6-3 shows a typical application where the MAX24287 connects a MAC with a GMII interface to an
SGMII switch chip. Through the MDIO interface, system software configures the MAX24287 to match the MAC
mode and writes the MAX24287's AN_ADV register to also match the MAC mode. The MAX24287 then transfers
the speed and mode over the SGMII interface as specified in the SGMII specification. The switch chip receives this
information and configures its port to match.
Figure 6-3. Management Information Flow Options, Case 2, SGMII Switch Chip
GMII
Transfer Speed Control
Acknowledge Speed contol
SGMII
RXD[7:0]
MAC
(GMII)
RX_CLK
125MHz
TXD[7:0]
CDR
MAX24287
RD
TD
Switch
Chip
GTX_CLK
125MHz
MDIO
Case 3 in Figure 6-4 shows a typical application where the MAX24287 connects a MAC with a GMII interface to an
optical interface. In this case the MAX24287 provides the 1000BASE-X PCS and PMA functions for the optical
interface. Through the MDIO interface, system software configures the MAX24287 to match the MAC mode, both
of which need to be 1000 Mbps speed. The MAX24287 then auto-negotiates with its link partner. This 1000BASEX auto-negotiation is primarily to establish the pause functionality of the link. The MAX24287's auto-negotiation
support is described in section 6.7.
21
_________________________________________________________________________________________________ MAX24287
Figure 6-4. Management Information Flow Options, Case 3, 1000BASE-X Interface
1000BASE-X Auto-negotiation
GMII
1000BASE-X
RXD[7:0]
MAC
(GMII)
RX_CLK
125MHz
TXD[7:0]
GTX_CLK
125MHz
CDR
MAX24287
RD
TD
Optical
Interface
(e.g. SFP Module)
MDIO
22
_________________________________________________________________________________________________ MAX24287
6.5
Serial Interface – 1000BASE-X or SGMII
The high-speed serial interface is compatible with the specification of the 1000BASE-CX PMD service interface
TP1 as defined in 802.3 clause 39. It is also compatible with the specification of the SGMII interface and can
connect to optical PMD modules in 1000BASE-SX/LX interfaces.
On this interface the MAX24287 transmits a 1250Mbaud differential signal on the TDP/TDN output pins. DDR
clocking is used, and the transmit interface outputs a 625MHz differential clock signal on the TCLKP/TCLKN output
pins. In the receive direction the clock and data recovery (CDR) block recovers both clock and data from the
incoming 1250Mbaud signal on RDP/RDN. A separate receive clock signal is not needed.
Signal Format, Coupling, Termination. The serial interface passes data at 1.25 Gbaud using a CML differential
output and an any-format differential input. The CML TDP/TDN outputs have internal 50Ω pullup resistors to
TVDD33. The differential input RDP/RDN does not have internal termination, and an external 100Ω termination
resistor between RDP and RDN is recommended. The high-speed serial interface pins are typically connected with
neighboring components using AC coupling as shown in Figure 6-5.
Figure 6-5. Recommended External Components for High-Speed Serial Interface
50Ω
10
0 Ω
Signal
Source
10k
50Ω
Signal
Destination
MAX24287
+
50Ω
10
0 Ω
Receiver
-
40k
50Ω
40k
CML
Driver
RVDD33
10k
50Ω
50Ω
MAX24287 TVDD33
16mA
Receive Loss-of-Signal. The device's receiver logic has an ALOS input pin through which analog loss-of-signal
(ALOS) can be received from a neighboring optical transceiver module, if the high-speed serial signal is
transmitted/received optically. The IR.ALOS bit is set when the ALOS pin goes high. ALOS can cause an interrupt
if enabled by IR.ALOS_IE.
In addition, the clock-and-data recovery block (CDR) indicates loss-of-signal when it does not detect any transitions
in 24 bit times. The IR.RLOS latched status bit is set when the CDR indicates loss-of-signal. RLOS can cause an
interrupt if enabled by IR.RLOS_IE.
Receive Loss-of-Lock. The receive clock PLL in the CDR locks to the recovered clock from the RDP/RDN pins
and produces several receive-side clock signals. If the receive clock PLL loses lock, it sets IR.RLOL, which can
cause an interrupt if enabled by IR.RLOL_IE.
Transmit Clock. The TCLKP/TCLKN differential output can be enabled and disabled using CR.TCLK_EN.
Disabled means the output drivers for TCLKP and TCLKN are disabled (high impedance) and the internal 50Ω
termination resistors pull both TCLKP and TCLKN up to 3.3V.
DC Electrical Characteristics. See section 9.2.2.
AC Electrical Characteristics. See section 9.3.3.
23
_________________________________________________________________________________________________ MAX24287
6.6
Parallel Interface – GMII, RGMII, TBI, RTBI, MII
The parallel interface can be configured as GMII, MII or TBI compliant to IEEE 802.3 clauses 35, 22 and 36,
respectively. It can also be configured as reduced pin count RGMII or RTBI compliant to the HP document RGMII
Version 1.3 12/10/2000. A summary of the parallel interface modes is show in Table 6-7 below.
Table 6-7. Parallel Interface Modes
Mode
TBI, normal
TBI, 1 Rx clock
RTBI
GMII
RGMII-1000
RGMII-100
RGMII-10
MII-100 DCE
MII-10 DCE
MII-100 DTE
MII-10 DTE
Baud Rate,
Mbps
1250
1250
1250
1000
1000
100
10
100
10
100
10
Data Transfer Per Cycle,
# of Wires Per Direction
10-bit codes, 10 wires
10-bit codes, 10 wires
10-bit codes, 5 wires, DDR
8-bit data, 8 wires
8-bit data, 4 wires, DDR
4-bit data, 4 wires
4-bit data, 4 wires
4-bit data, 4 wires
4-bit data, 4 wires
4-bit data, 4 wires
4-bit data, 4 wires
Transmit Clock
Input, 125MHz
Input, 125MHz
Input, 125MHz
Input, 125MHz
Input, 125MHz
Input, 25MHz
Input, 2.5MHz
Output, 25MHz
Output, 2.5MHz
Input, 25MHz
Input ,2.5MHz
Receive Clock
Output, 2 62.5MHz
Output, 1 125MHz
Output, 125MHz
Output, 125MHz
Output, 125MHz
Output 25MHz
Output, 2.5MHz
Output, 25MHz
Output, 2.5MHz
Input, 25MHz
Input, 2.5MHz
Full
Duplex
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Half
Duplex
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
The parallel interface mode is controlled by GMIICR.SPD[1:0]. TBI and MII options are specified by
GMIICR.TBI_RATE and GMIICR.DTE_DCE, respectively.
6.6.1 GMII Mode
The MAX24287's GMII interface is compliant to IEEE 802.3 clause 35 but only operates full duplex. Half duplex
operation is not supported, and the TX_ER pin is ignored. The PHY therefore does not receive the following from
the MAC: carrier extend, carrier extend error, and transmit error propagation as described in 802.3 section
35.2.1.6, section 35.2.2.5 and Table 35-1. These features are not needed for full duplex operation.
The parallel interface can be configured for GMII mode using software configuration or pin configuration at reset.
For pin configuration (see section 6.1) one of the following combinations of pin states must be present during
device reset:
•
•
COL=0, RXD[1:0]=10, CRS=0
COL=1, CRS=0
For software configuration, the following register fields must be set: GMIICR.SPD[1:0]=10 and GMIICR.DDR=0.
See IEEE 802.3 clause 35 for functional timing diagrams. GMII DC electrical characteristics are listed in section
9.2.1. AC electrical characteristics are listed in section 9.3.4 and 9.3.5.
Table 6-8. GMII Parallel Bus Pin Naming
Pin Name
802.3 Pin Name
Function
RXCLK
RX_CLK
Receive 125MHz clock output
RXD[7:0]
RXD[7:0]
Receive data output
RX_DV
RX_DV
Receive data valid output
RX_ER
RX_ER
Receive data error output
CRS
CRS
Receive carrier sense
COL
COL
Receive collision (held low in GMII mode)
TXCLK
--Outputs 125MHz from the TX PLL for MAC when GMIICR.TXCLK_EN=1.
GTXCLK
GTX_CLK
Transmit 125MHz clock input
TXD[7:0]
TXD[7:0]
Transmit data input
TX_EN
TX_EN
Transmit data enable input
TX_ER
TX_ER
Transmit data error input (not used - ignored)
24
_________________________________________________________________________________________________ MAX24287
6.6.2 TBI Mode
6.6.2.1 Configuration
The TBI and RTBI interfaces are used when a neighboring component implements the 802.3 PCS layer and
therefore transmits and receives 10-bit 8B/10B-encoded data. The parallel interface can be configured for TBI
mode using software configuration or pin configuration at reset. For pin configuration (see section 6.1) device pins
must be set as follows during device reset: COL=0, RXD[1:0]=11, CRS=0. For software configuration, the following
register fields must be set: GMIICR.SPD[1:0]=11 and GMIICR.DDR=0. When the parallel interface is in TBI mode,
the MAX24287 does not perform 8B/10B encoding or decoding or any auto-negotiation functions.
6.6.2.2 Normal TBI with Two 62.5MHz Receive Clocks
The normal TBI interface specified in IEEE 802.3 section 36.3.3 has a 10-bit data bus in each direction, a 125MHz
transmit clock (GTXCLK), two 62.5MHz receive clocks (RXCLK and RXCLK1) and a receive COMMA signal. See
Table 6-9. In the transmit path the MAX24287 samples tx_code_group[9:0] on rising edges of GTXCLK. In the
receive path, RXCLK and RXCLK1 are 180 degrees out of phase from each other (i.e. inverted) and together
provide rising edges every 8 ns. The MAX24287 updates the rx_code_group[9:0] and COMMA signals before
every RXCLK rising edge and every RXCLK1 rising edge. The neighboring component then samples
rx_code_group[9:0] and COMMA every RXCLK rising edge and every RXCLK1 rising edge. The normal TBI
interface is selected in hardware by setting RX_DV=1 during device reset or in software by setting
GMIICR:TBI_RATE=1. See IEEE 802.3 section 36.3.3 for functional timing diagrams. TBI DC electrical
characteristics are listed in section 9.2.1. AC electrical characteristics are listed in section 9.3.4 and 9.3.5.
Table 6-9. TBI Parallel Bus Pin Naming (Normal Mode}
Pin Name
802.3 Pin Name
Function
RXCLK
PMA_RX_CLK0
Receive 62.5MHz clock output phase 0, odd numbered code-groups
RXD[7:0]
rx_code_group[7:0] Receive data bits 7 to 0 output
RX_DV
rx_code_group[8]
Receive data bit 8 output
RX_ER
rx_code_group[9]
Receive data bit 9 output
CRS
COM_DET
Comma detection output
COL
--Not used
TXCLK/RXCLK1 PMA_RX_CLK1
Receive 62.5MHz clock output phase 1, even numbered code-groups
GTXCLK
PMA_TX_CLK
Transmit 125MHz clock input
TXD[7:0]
tx_code_group[7:0] Transmit data bits 7 to 0 input
TX_EN
tx_code_group[8]
Transmit data bit 8 input
TX_ER
tx_code_group[9]
Transmit data bit 9 input
6.6.2.3 One-Clock TBI Mode
An alternate TBI receive clocking scheme is also available in which the two 62.5MHz receive clocks are replaced
by a single 125MHz receive clock on the RXCLK pin. See Table 6-10. In this mode a neighboring component uses
rising edges of the RXCLK signal to sample rx_code_group[9:0]. The alternate TBI receive clocking scheme is
selected in hardware by setting RX_DV=0 during device reset or in software by setting GMIICR:TBI_RATE=0.
Table 6-10. TBI Parallel Bus Pin Naming (One-Clock Mode)
Pin Name
802.3 Pin Name
Function
RXCLK
--Receive 125MHz clock output
RXD[7:0]
rx_code_group[7:0] Receive data bits 7 to 0 output
RX_DV
rx_code_group[8]
Receive data bit 8 output
RX_ER
rx_code_group[9]
Receive data bit 9 output
CRS
COM_DET
Comma detection output
COL
--Not used
TXCLK
--Outputs 125MHz from the TX PLL for use by the MAC when
GMIICR.TXCLK_EN=1.
GTXCLK
PMA_TX_CLK
Transmit 125MHz clock input
25
_________________________________________________________________________________________________ MAX24287
Pin Name
TXD[7:0]
TX_EN
TX_ER
802.3 Pin Name
tx_code_group[7:0]
tx_code_group[8]
tx_code_group[9]
Function
Transmit data bits 7 to 0 input
Transmit data bit 8 input
Transmit data bit 9 input
6.6.2.4 Frequency-Locked Through Clocking, No Buffers
The REFCLK signal is internally multiplied to produce the 1250MHz clock used to transmit data on the serial
interface TDP/TDN pins. This 1250MHz clock is also used to create the 625MHz clock on the serial interface
TCLKP/TCLKN pins. The REFCLK signal must therefore be ±100ppm and low jitter (<5ps rms measured using a
12kHz to 2MHz bandpass filter). The RXCLK and RXCLK1 signals (normal TBI mode) or only the RXCLK signal
(one-clock TBI mode) are divided down from the 1250MHz clock recovered from the serial data stream on the
RDP/RDN pins.
For proper operation in TBI mode, the signal on the GTXCLK pin must be frequency locked to the signal on the
REFCLK pin. One easy way to achieve this is to configure the MAX24287 to output on a GPIO pin a 125MHz
signal from the TX PLL (which is locked to the signal on the REFCLK pin). See section 6.2. This 125MHz signal is
then wired to a clock input on the neighboring MAC/PCS component. The neighboring component then uses that
signal as GTXCLK.
6.6.2.5 Comma Detection and Code-Group Alignment
In the receive path, if PCSCR.EN_CDET=1 then code-group alignment is performed based on comma detection.
When a comma+ pattern (0011111xxx) or a comma– (1100000xxx) occurs in the serial bit stream in a K28.1 or
K28.5 code-group, three things happen: (1) the code-group containing the comma is output on rx_code_group[9:0]
with the alignment shown in 802.3 Figure 36-3, (2) the COMMA pin is driven high, and (3) the PMA_RX clocks are
stretched as needed so that both rx_code_group[9:0] and COMMA are setup to be sampled by the neighboring
component on the rising edge of RXCLK1 (normal TBI mode) or RXCLK (one-clock TBI mode). Commas in K28.7
code-groups are ignored.
When PCSCR.EN_CDET=0, the receive path does not perform any comma detection or code-group alignment,
and the COMMA signal is held low.
6.6.2.6 TBI Control Pins
The MAX24287 TBI interface does not have the TBI EN_CDET pin mentioned in 802.3 section 36.3.3. Comma
detection is enabled/disabled by the PCSCR.EN_CDET register bit instead.
The MAX24287 TBI interface does not have the EWRAP pin mentioned in 802.3 section 36.3.3. Control for this
loopback is handled by the PCSCR.TLB register bit. See section 6.10.
The MAX24287 TBI interface also does not have the –LCK_REF pin because such a control is not needed by the
receive clock and data recovery block.
6.6.3 RGMII Mode
The RGMII interface has three modes of operation to support three Ethernet speeds: 10, 100 and 1000Mbps. This
document refers to these three modes as RGMII-1000 for 1000Mbps operation, RGMII-100 for 100Mbps operation
and RGMII-10 for 10Mbps operation. RGMII is specified to support speed changes among the three rates as
needed. The RGMII specification document can be downloaded from http://www.hp.com/rnd/pdfs/RGMIIv1_3.pdf
or can be found by a web search for "RGMII 1.3". This document also specifies the RTBI interface discussed in
section 6.6.4.
The parallel interface can be configured for RGMII modes using software configuration or pin configuration at reset.
For pin configuration (see section 6.1) one of the following combinations of pin states must be present during
device reset:
26
_________________________________________________________________________________________________ MAX24287
•
•
COL=0, RXD[1:0]=xx, CRS=1 (xx=00 for RGMII-10, xx=01 for RGMII-100, xx=10 for RGMII-1000)
COL=1, CRS=1
(RGMII-1000 only)
For software configuration, the following register fields must be set: GMIICR.SPD[1:0]=xx and GMIICR.DDR=1
(where xx values are the same as shown above for RXD[1:0]).
On the receive RGMII interface the MAX24287 does not report in-band status for link state, clock speed and duplex
during normal inter-frame. This status indication is defined as optional in the RGMII specification.
Table 6-11. RGMII Parallel Bus Pin Naming
Pin Name
RGMII Pin Name
Function
RXCLK
RXC
Receive 125MHz clock output
RXD[3:0]
RD[3:0]
Receive data bits 3 to 0 and 7 to 4 output
RX_DV
RX_CTL
Receive data valid output
RX_ER
--Not used
CRS
--Outputs carrier sense signal
COL
--Outputs collision signal
TXCLK
--Outputs 125MHz from the TX PLL for use by the MAC when
GMIICR.TXCLK_EN=1.
GTXCLK
TXC
Transmit 125MHz clock input
TXD[3:0]
TD[3:0]
Transmit data bits 3 to 0 and 7 to 4 input
TX_EN
TX_CTL
Transmit data enable input
TX_ER
--Not used
6.6.3.1 RGMII-1000 Mode
RGMII-1000 is a reduced pin count alternative to the GMII interface. Pin count is reduced by sampling and
updating data and control signals on both clock edges. For data, only four data lines are used, as shown in Table
6-11. Data bits 3:0 are latched on the rising edge of the clock, and data bits 7:4 are latched on the falling edge. The
transmit control signals TX_EN and TX_ER are multiplexed onto a single TX_CTL signal. TX_EN is latched on the
rising edge of the transmit clock TXC while a modified TX_ER signal is latched on the falling edge of TXC. The
receive control signals RX_DV and RX_ER are multiplexed onto a single RX_CTL signal. RX_DV is latched on the
rising edge of the receive clock RXC while a modified RX_ER signal is latched on the falling edge of RXC.
The modified TX_ER signal = (GMII TX_ER) XOR (GMII TX_EN). The modified RX_ER signal = (GMII_RX_ER)
XOR (GMII_RX_DV). These modifications are done to reduce power by eliminating control signal toggling at
125MHz during normal data transmission and during idle.
On the transmit side of the parallel interface the MAX24287 ignores the TX_ER component of the TX_CTL signal,
as it does in all 1000Mbps interface modes, since it only operates full-duplex at 1000Mbps. Therefore the 0,1
TX_CTL encoding is interpreted as 0,0 (idle, normal interframe). Similarly, the 1,0 TX_CTL encoding is interpreted
as 1,1 (normal data transmission).
See the RGMII v1.3 specification document for functional timing diagrams. DC electrical characteristics are listed in
section 9.2.1. AC electrical characteristics are listed in section 9.3.4 and 9.3.5.
6.6.3.2 RGMII-10 and RGMII-100 Modes
The RGMII interface can be used to convey 10 and 100Mbps Ethernet data. The theory of operation at these lower
speeds is similar to RGMII-1000 mode as described above but with a 2.5MHz clock for 10Mbps operation, a
25MHz clock for 100Mbps operation, and data latched and updated only on the rising edge of the clock. The
RXD[3:0] pins maintain their values during the negative edge of RXCLK. The control signals are conveyed on both
clock edges exactly as described for RGMII-1000. See the RGMII v1.3 specification document for functional timing
diagrams. DC electrical characteristics are listed in section 9.2.1. AC characteristics are listed in section 9.3.4 and
9.3.5.
27
_________________________________________________________________________________________________ MAX24287
6.6.3.3 Clocks
The RXCLK clock output is 125MHz, 25MHz or 2.5MHz, depending on RGMII mode. It is derived from the
recovered clock from the receive serial data.
The GTXCLK clock input must be 125MHz, 25MHz or 2.5MHz ±100 ppm. The GTXCLK clock is not used as the
source of the serial data transmit clock.
6.6.4 RTBI Mode
The RGMII v1.3 specification document also specifies a reduced pin-count TBI interface called RTBI. This interface
behaves similarly to the RGMII-1000 interface specified in section 6.6.3.1, but conveys 10-bit data and no control
information. (TBI control signals such as EWRAP and EN_CDET are handled by control register settings.) The
TX_EN (TX_CTL) and RX_DV (RX_CTL) pins behave as additional data pins in this mode, as shown in Table 6-12.
Data is sampled and updated on both clock edges as is done in RGMII-1000 mode. On the positive clock edge
RXD[3:0] = rx_code_group[3:0], RX_DV = rx_code_group[4], TXD[3:0] = tx_code_group[3:0] and TX_EN =
tx_code_group[4]. On the negative clock edge RXD[3:0] = rx_code_group[5:8], RX_DV = rx_code_group[9],
TXD[3:0] = tx_code_group[5:8] and TX_EN = tx_code_group[9].
Unlike the normal TBI interface, which has two 62.5MHz receive clocks, RTBI has a single 125MHz clock signal in
each direction.
The parallel interface can be configured for RTBI mode using software configuration or pin configuration at reset.
For pin configuration (see section 6.1) device pins must be set as follows during device reset: COL=0,
RXD[1:0]=11, CRS=1. For software configuration, the following register fields must be set: GMIICR.SPD[1:0]=11
and GMIICR.DDR=1. When the parallel interface is in RTBI mode, the MAX24287 does not perform 8B/10B
encoding or decoding or any auto-negotiation functions.
For proper operation in RTBI mode, the signal on the GTXCLK pin must be frequency locked to the signal on the
REFCLK pin. One easy way to achieve this is to configure the MAX24287 to output on a GPIO pin a 125MHz
signal from the TX PLL (which is locked to the signal on the REFCLK pin). See section 6.2. This 125MHz signal is
then wired to a clock input on the neighboring MAC/PCS component. The neighboring component then uses that
signal as GTXCLK.
See the RGMII v1.3 specification document for functional timing diagrams. RGMII DC electrical characteristics are
listed in section 9.2.1. AC electrical characteristics are listed in section 9.3.4 and 9.3.5.
Table 6-12. RTBI Parallel Bus Pin Naming
Pin Name
Spec Pin Name
Function
RXCLK
RXC
Receive 125MHz clock output
RXD[3:0]
RD[3:0]
Receive data bits 3 to 0 and 8 to 5 output
RX_DV
RX_CTL
Receive data bits 4 and 9 output
RX_ER
--Not used
CRS
COM_DET
Comma detection output
COL
--Not used
TXCLK
--Outputs 125MHz from the TX PLL for use by the MAC when
GMIICR.TXCLK_EN=1.
GTXCLK
TXC
Transmit 125MHz clock input
TXD[3:0]
TD[3:0]
Transmit data bits 3 to 0 and 8 to 5 input
TX_EN
TX_CTL
Transmit data bits 4 and 9 input
TX_ER
--Not used
28
_________________________________________________________________________________________________ MAX24287
6.6.5 MII Mode
The MAX24287's MII interface is compliant to IEEE 802.3 clause 22 except that TX_ER is ignored (and therefore
the MAX24287 does not receive transmit error propagation from the MAC).
The parallel interface can be configured for MII mode using software configuration or pin configuration at reset. For
pin configuration (see section 6.1) device pins must be set as follows during device reset: COL=0, RXD[1:0]=0x,
CRS=0 (x=0 for 10Mbps, x=1 for 100Mbps). For software configuration, the following register fields must be set:
GMIICR.SPD[1:0]=0x and GMIICR.DDR=0.
Since the MAX24287 can be used in a variety of applications, it can be configured to source the TXCLK and
RXCLK as a PHY normally does or to accept TXCLK and RXCLK from a neighboring component. The former case
is called DCE mode; the latter is called DTE mode. DTE/DCE selection is controlled by the GMIICR.DTE_DCE
register bit.
In DTE mode the MAX24287 is configured for operation on the MAC side of the MII. Both TXCLK and RXCLK are
inputs at 2.5MHz (10Mbps MII) or 25MHz (100Mbps MII) ±100 ppm. TXCLK is not used as the serial data transmit
clock (which is derived from the REFCLK input instead).
In DCE mode the MAX24287 is configured for operation on the PHY side of the MII. Both TXCLK and RXCLK are
outputs at 2.5MHz or 25MHz. The TXCLK output clock is derived from the REFCLK input. The RXCLK output clock
is derived from the recovered clock from the receive serial data when a receive signal is present or from REFCLK
when no receive signal is present.
See 802.3 clause 22 for functional timing diagrams. MII DC electrical characteristics are listed in section 9.2.1. AC
electrical characteristics are listed in section 9.3.4 and 9.3.5.
On the transmit MII interface the MAX24287 requires that the preamble including the SFD must be an even number
of nibbles (i.e. number of nibbles divided by 2 is an integer). On the receive MII interface the MAX24287 always
outputs an even number of nibbles of preamble.
Table 6-13. MII Parallel Bus Pin Naming
Pin Name
802.3 Pin Name
Function
RXCLK
RX_CLK
Receive 2.5 or 25MHz clock, can be input or output
RXD[3:0]
RXD[3L0]
Receive data nibble output
RX_DV
RX_DV
Receive data valid output
RX_ER
RX_ER
Receive data error output
CRS
CRS
Receive carrier sense
COL
COL
Receive collision
TXCLK
TX_CLK
Transmit 2.5 or 25MHz clock, can be input or output
GTXCLK
--Not used
TXD[3:0]
TXD[3:0]
Transmit data nibble input
TX_EN
TX_EN
Transmit data enable input
TX_ER
TX_ER
Transmit data error input (not used - ignored)
29
_________________________________________________________________________________________________ MAX24287
6.7
Auto-Negotiation (AN)
In the MAX24287 the auto-negotiation mechanism described in IEEE 802.3 Clause 37 is used for auto-negotiation
between IEEE 802.3 1000BASE-X link partners as well as the transfer of SGMII PHY status to a neighboring MAC
as described in the Cisco Serial-SGMII document ENG-46158. The 802.3 1000BASE-X next page functionality is
not supported. The PCSCR.BASEX register bit controls the link timer time-out mode of the auto-negotiation
protocol.
The auto-negotiation mechanism between link partners uses a special code set that passes a 16-bit value called
tx_Config_Reg[15:0] as defined in IEEE 802.3. The auto-negotiation transfer starts when BMCR.AN_START is set
(self clearing) and BMCR.AN_EN is set. The tx_Config_Reg value is continuously sent with the ACK bit (bit 14)
clear and the other bits sourced from the AN_ADV register. When the device receives a non-zero rx_Config_Reg
value it sets the ACK bit in the tx_Config_Reg, saves the rx_Config_Reg bits to the AN_RX register, and sets the
AN_EXP.PAGE and IR.PAGE bits to tell system software that a new page has arrived. The tx_Config_Reg
transmission stops when the link timer times out after 10ms in 1000BASE-X mode or after 1.6ms in SGMII mode.
System software must complete the auto-negotiation function by processing the AN_RX register and configuring
the hardware appropriately.
The fields of the auto-negotiation registers AN_ADV and AN_RX have different meanings when used in
1000BASE-X or SGMII mode. See section 6.7.1 for 1000BASE-X and section 6.7.2. for SGMII.
By default, an internal watchdog timer monitors the auto-negotiation process. If the link is not up within 5 seconds
after auto-negotiation was started, the watchdog timer restarts the auto-negotiation. This watchdog timer can be
disabled by setting PCSCR.WD_DIS=1.
6.7.1 1000BASE-X Auto-Negotiation
In 1000BASE-X auto-negotiation, two link partners send their specific capabilities to each other. Each link partner
compares the capabilities that it advertises in its AN_ADV register against its link partner's advertised abilities,
which are stored in the AN_RX register when received. Each link partner uses the same arbitration algorithm
specified in IEEE 802.3 clause 37.2 to determine how it should configure its hardware, and, therefore, the two link
partners' configurations should match. However, if there is no overlap of capabilities between the link partners, the
RF bits (Remote Fault, see Table 6-14) are set to 11, and the auto-negotiation process is started again. An external
processor configures the advertised abilities, reads the link partner’s abilities, performs the arbitration algorithm,
and sets the RF bits as needed.
The MAX24287 AN block implements the auto-negotiation state machine shown in IEEE 802.3 Figure 37-6. It also
generates an internal link-down status signal whenever the AN state machine is in any state other than
AN_DISABLE_LINK_OK or LINK_OK. This link-down signal is used to clear the active-low BMSR.LINK_ST bit and
is used to squelch output clock signals on GPIO pins when CR.RCSQL=1.
System software can configure the MAX24287 for 1000BASE-X auto-negotiation by setting PCSCR.BASEX=1 and
BMCR.AN_EN=1.
The MAX24287 can also be configured for 1000BASE-X auto-negotiation by pin settings at reset without software
configuration. In 15-pin configuration mode (COL=0 at reset), if RXD[1:0]=10 and GPO2=1 and RX_DV=1 at reset
then PCSCR:BASEX is set to 1 to indicate 1000BASE-X mode and BMCR.AN_EN is set to 1 to enable autonegotiation. In 3-pin configuration (COL=1 at reset), if GPO2=1 then PCSCR:BASEX is set to 1 to indicate
1000BASE-X mode and auto-negotiation is automatically enabled. In both pin configuration modes the AN_ADV
register's reset-default value causes device capabilities to be advertised as follows: full-duplex only, no pause
support, no remote fault. See section 6.1 for details about pin configuration at reset.
30
_________________________________________________________________________________________________ MAX24287
Figure 6-6. Auto-Negotiation with a Link Partner over 1000BASE-X
<GMII>
1000BASE-SX/LX
RXD[7:0]
RX_CLK
125 MHz
TXD[7:0]
CDR
MAX
24287
TX_CLK
125 MHz
TD
RD
Optical
Module
Optical
Module
Link
Partner
RD
TD
BASEX=1
CDR
AN Advertisement
AN Acknowledgement
AN Advertisement
AN Acknowledgement
The tx_Config_Reg and rx_Config_Reg format for 1000BASE-X auto-negotiation is shown in Figure 6-7. All
reserved bits are set to 0. The ACK bit is set and detected by the PCS auto-negotiation hardware.
Figure 6-7. 1000BASE-X Auto-Negotiation tx_Config_Reg and rx_Config_Reg Fields
lsb
D0 D1
D2 D3 D4
rsvd rsvd rsvd rsvd rsvd
msb
D8 D9 D10 D11 D12 D13 D14 D15
D5 D6
D7
FD
PS1 PS2 rsvd rsvd rsvd RF1 RF2 Ack
HD
NP
The AN_ADV register is the source of tx_Config_Reg. The received rx_Config_Reg is written to the AN_RX
register. The auto-negotiation fields for AN_ADV and AN_RX are described in Table 6-14 and Table 6-15.
Table 6-14. AN_ADV 1000BASE-X Auto-Negotiation Ability Advertisement Register (MDIO 4)
Bit(s)
Name
15
NP
14
13:12
Reserved
RF
11:9
8:7
ZERO1
PS
6
HD
5
FD
Description
R/W
Reset
Next Page capability is not supported. This bit should always
be set to 0.
Ignore on Read
Remote Fault. Used to indicate to the link partner that a
remote fault condition has been detected:
00 = No Error, Link OK
01 = Link Failure
10 = Off Line
11 = Auto-Negotiation Error
Always write 000
Pause. Used to indicate pause capabilities to the link
partner.
00 = No Pause
01 = Symmetric Pause
10 = Asymmetric Pause
11 = Both Symmetric and Asymmetric Pause
Used to indicate ability to support half duplex to link partner.
Since half duplex is not supported always write 0.
Used to indicate ability to support full duplex to link partner.
0 = Do not advertise full duplex capability
1 = Advertise full duplex capability
RW
0
RO
RW
0
00
RW
RW
0
00
RW
0
RW
1
31
_________________________________________________________________________________________________ MAX24287
Bit(s)
4:0
Name
ZERO2
Description
R/W
Reset
RW
00000
Description
R/W
Reset
Next Page. Used by link partner to indicate its PCS has a
Next Page to exchange.
0 = No Next Page exchange request
1 = Next Page exchange request
Indicates link partner successfully received the previously
transmitted base page.
Remote Fault. Link partner uses this field to indicate a
remote fault condition has been detected.
00 = No Error, Link OK
01 = Link Failure
10 = Off Line
11 = Auto-Negotiation Error
Ignore on Read
Pause. Used by link partner to indicate its pause capabilities.
00 = No Pause
01 = Symmetric Pause
10 = Asymmetric Pause
11 = Both Symmetric and Asymmetric Pause
Used by link partner to indicate ability to support half duplex.
0 = Not able to support half duplex
1 = Able to support half duplex
Used by link partner to indicate ability to support full duplex.
0 = Not able to support full duplex
1 = Able to support full duplex
Ignore on Read
RO
0
RO
0
RO
0
RO
RO
0
0
RO
0
RO
0
RO
0
Always write 00000
Table 6-15. AN_RX 1000BASE-X Auto-negotiation Ability Receive Register (MDIO 5)
Bit(s)
Name
15
NP
14
Acknowledge
13:12
RF
11:9
8:7
Reserved
PS
6
HD
5
FD
4:0
Reserved
6.7.2 SGMII Control Information Transfer
SGMII control information transfer mode is enabled by setting PCSCR.BASEX=0. According the SGMII
specification, a PHY sends control information to the neighboring MAC using the same facilities used for
1000BASE-X auto-negotiation (AN_ADV, AN_RX, tx_Config_Reg, rx_Config_Reg, see section 6.7.1). Since the
MAX24287 sits between a PHY and a MAC it can behave as the transmitter or receiver in the control information
transfer process depending on how it is connected to neighboring components.
When the MAX24287 is connected to a 1000BASE-T PHY, for example, the PHY transfers control information to
the MAX24287, which then acknowledges the information transfer. System software then reads the control
information from the MAX24287 and configures the MAX24287 to match the PHY. This situation is shown in case
(a) of Figure 6-8.
In other scenarios, such as when the MAX24287 is connected by SGMII to a switch IC, shown in case (b) of Figure
6-8, the MAX24287 transfers control information to the neighboring component, which then acknowledges the
information transfer. System software then reads the control information from the neighboring component and
configures that component to match the MAX24287.
The MAX24287 AN block implements the auto-negotiation state machine shown in IEEE 802.3 Figure 37-6. It also
generates an internal link-down status signal whenever the AN state machine is in any state other than
AN_DISABLE_LINK_OK or LINK_OK. This link-down signal is used to clear the active-low BMSR.LINK_ST bit and
is used to squelch output clock signals on GPIO pins when CR.RCSQL=1.
32
_________________________________________________________________________________________________ MAX24287
Figure 6-8. SGMII Control Information Generation, Reception and Acknowledgement
Speed Control - (a) PHY Initiated
<SGMII>
ETH
Peripherial
RXD[7:0]
CDR
RX_CLK
125 MHz
MAC
MAX24287
TXD[7:0]
<GMII/MII>
RD
CAT5
Media
PHY
TD
TX_CLK
125 MHz
TCLK
625 MHz
MDIO
Initiate Speed Control
Acknowledge Speed contol
Speed Control - (b) Device Initiated
(to allow Switch to connect to slower peripheral MAC devices)
<SGMII>
ETH
Peripherial
RXD[3:0]
MAC
CDR
RX_CLK
25 MHz
MAX24287
TXD[3:0]
SDH/PDH
Mapper
<MII>
TX_CLK
25 MHz
RD
TD
M
A
C
Switch
TCLK
625 MHz
MDIO
Initiate Speed Control
Acknowledge Speed contol
The control information fields carried on the SGMII are: link status (up/down), link speed (1000/100/10Mbps) and
duplex mode (full/half). The tx_Config_Reg and rx_Config_Reg format for SGMII control information transfer is
shown in Figure 6-9. All reserved bits are set to 0. The ACK bit is set and detected by the PCS hardware.
Figure 6-9. SGMII tx_Config_Reg and rx_Config_Reg Fields
lsb
D0 D1
1
D2 D3 D4
D5 D6
D7
msb
D8 D9 D10 D11 D12 D13 D14 D15
rsvd rsvd rsvd rsvd rsvd rsvd rsvd rsvd rsvd Spd Spd dplx rsvd Ack
LK
When the MAX24287 is the control information receiver, its AN_ADV register must be set to 0x0001. The received
control information is automatically stored in the AN_RX register.
When the MAX24287 is the control information transmitter, the information is sourced from its AN_ADV register.
The MAX24287 can be configured to automatically send SGMII control information by pin settings at reset without
software configuration. In 15-pin configuration mode (COL=0 at reset), if RXD[1:0]=10 and GPO2=0 and RX_DV=1
at reset then PCSCR:BASEX is set to 0 to indicate SGMII mode, BMCR.AN_EN is set to 1 to enable autonegotiation, and the AN_ADV SPD[1:0] bits are set by the reset values of the RXD[1:0] pins. In 3-pin configuration
(COL=1 at reset), if GPO2=0 then PCSCR:BASEX is set to 0 to indicate SGMII mode, auto-negotiation is
automatically enabled, and the AN_ADV SPD[1:0] bits are set to 10 (1000Mbps). In both pin configuration modes
the AN_ADV register's reset-default value causes device capabilities to be advertised as follows: full-duplex only,
link up. See section 6.1 for details about pin configuration at reset.
The AN_ADV register is the source of tx_Config_Reg value. The received rx_Config_Reg value is written to the
AN_RX register. These meanings are described in Table 6-16 and Table 6-17.
33
_________________________________________________________________________________________________ MAX24287
Table 6-16. AN_ADV SGMII Configuration Information Register (MDIO 4)
Bit(s)
Name
15
LK
14
13
12
Reserved
ZERO1
DPLX
11:10
SPD[1:0]
9:1
0
ZERO2
ONE
Description
Link Status.
0 = Link down
1 = Link up
Ignore on Read
Always write 0
Duplex mode
0 = Half duplex
1 = Full duplex
Link speed
00 = 10Mbps
01 = 100Mbps
10 = 1000Mbps
11 = Reserved
Always write 000000000
Always write 1
R/W
Reset
RW
Note 1
RO
RW
RW
0
0
1
RW
Note 1
RW
RW
0
1
R/W
Reset
RO
0
RO
RO
0
0
RO
0
RO
0
Note 1: See the AN_ADV register description.
Table 6-17. AN_RX SGMII Configuration Information Receive Register (MDIO 5)
Bit(s)
Name
15
LK
14:13
12
Reserved
DPLX
11:10
SPD
9:0
Reserved
Description
Link partner link status.
0 = Link down
1 = Link up
Ignore on read
Link partner duplex mode
0 = Half duplex
1 = Full duplex
Link partner link speed
00 = 10Mbps
01 = 100Mbps
10 = 1000Mbps
11 = Reserved
Ignore on read
34
_________________________________________________________________________________________________ MAX24287
6.8
Data Paths
The MAX24287 data paths perform bidirectional conversion between a parallel interface (GMII, RGMII, TBI, RTBI
or MII) and a 1.25Gbps serial interface (1000BASE-X or SGMII).
In GMII, RGMII and MII modes, the data paths implement the 802.3 PCS and PMA sublayers including autonegotiation. The parallel interface data is 8 bits wide. The PCS logic performs 8B/10B encoding and decoding. The
PMA logic performs 10:1 serialization and deserialization.
In TBI and RTBI modes, the MAX24287's PCS and auto-negotiation blocks are not used, and the data paths
implements only the PMA sublayer. The parallel interface data is 10 bits wide, and the PMA logic performs 10:1
serialization and deserialization.
6.8.1 GMII, RGMII and MII Serial to Parallel Conversion and Decoding
Refer to the block diagram in Figure 2-1. Clock and data are recovered from the incoming 1.25Gbps serial signal
on RDP/RDN. The serial data is then converted to 10-bit parallel data with 10-bit alignment determined by
detecting commas. The 10-bit code groups are then 8B/10B decoded by the PCS decoder as specified in 802.3
clause 36. After passing through a rate adaption buffer that accounts for phase and/or frequency differences
between recovered clock and MII clock, the 8-bit data is clocked out of the device to a neighboring MAC either 4
bits or 8 bits at a time. Half duplex is supported in 10 and 100Mbps modes but not in 1000Mbps modes. Carrier
extend is not supported in 1000Mbps modes.
6.8.2 GMII, RGMII and MII Parallel to Serial Conversion and Encoding
Refer to the block diagram in Figure 2-1. Parallel data is received from the MAC clocked by a 125MHz, 25MHz or
2.5MHz clock, either 4 bits or 8 bits at a time. The data then passes through a rate adaption buffer that accounts for
phase and/or frequency differences between MII clock and transmit clock. The 8-bit data is then 8B/10B encoded
by the PCS encoder as specified in 802.3 clause 36. The 10-bit code-groups are then serialized. The resulting
1.25Gbps serial data is transmitted to a neighboring 1000BASE-X optical module or SGMII-interface copper PHY.
Half duplex is supported in 10 and 100 Mbps modes but not in 1000 Mbps modes. Carrier extend is not supported
in 1000 Mbps modes.
6.8.3 TBI, RTBI Serial to Parallel Conversion and Decoding
In the block diagram in Figure 2-1, the PCS decoder is disabled because 8B/10B decoding is not done by the
MAX24287 in these modes. Clock and data are recovered from the incoming 1.25Gbps serial signal. The serial
data is then converted to 10-bit parallel data with 10-bit alignment set by detecting commas (PCSCR.EN_CDET=1)
or with no 10-bit alignment (EN_CDET=0, simple 10-bit SERDES mode). Data is clocked out of the device to a
neighboring component either 5 bits or 10 bits at a time.
6.8.4 TBI Parallel to Serial Conversion and Encoding
In the block diagram in Figure 2-1, the PCS encoder is disabled because 8B/10B encoding is not done by the
MAX24287 in these modes. Parallel data is received from the MAC clocked by a 125MHz clock, either 5 bits or 10
bits at a time. The 10-bit code-groups are then serialized. The resulting 1.25Gbps serial data is transmitted to a
neighboring 1000BASE-X optical module or SGMII-interface copper PHY.
6.8.5 Rate Adaption Buffers, Jumbo Packets and Clock Frequency Differences
The MAX24287 can handle jumbo packets up to 9001 bytes long as long as the clock frequencies of each rate
adaption buffer’s write clock and the read clock are both within ±100ppm of nominal.
35
_________________________________________________________________________________________________ MAX24287
For example, in GMII mode the transmit rate adaption buffer is written by GTXCLK and read by a 125MHz clock
frequency locked to the REFCLK signal. If GTXCLK and REFCLK are both maintained within ±100ppm of nominal
frequency then jumbo packets up to 9001 bytes long can be accommodated by the transmit rate adaption buffer.
6.9
Timing Paths
Figure 6-10. Timing Path Diagram
RX
Rate
Adaption
Buffer
RXCLK
RX
PCS
Decoder
625M
Deserializer
(RX BUFF)
125, 62.5a,
25, 2.5 MHz
RX PLL
(CDR)
RDP/RDN
125, 62.5a, 62.5b, 25, 2.5 MHz
RLB
62.5b
(2 clk TBI)
DLB
125, 62.5a, 62.5b, 25, 2.5 MHz
GTXCLK
125, 62.5a, 62.5b, 25, 2.5 MHz
125, 25, 2.5 MHz
TXCLK
125, 62.5b, 25, 2.5 MHz
TX
Rate
Adaption
Buffer
TX
PCS
Encoder
625M
Serializer
(TX BUFF)
TX
PLL
TCLKP/N
REFCLK
125, 25, 12.8, 10M
Numbers in the tables below are clock frequencies in MHz.
Table 6-18. Timing Path Muxes – No Loopback
TX Rate
TXCLK
Mode
Buffer Mux
Mux/Driver
GMII
RGMII 1000
RGMII 100
RGMII 10
MII 100 - DCE
MII 100 - DTE
MII 10 - DCE
MII 10 - DTE
TBI half rate
TBI full rate
RTBI
GTXCLK 125
GTXCLK 125
GTXCLK 25
GTXCLK 2.5
TX PLL 25
TXCLK 25
TX PLL 2.5
TXCLK 2.5
GTXCLK 125
GTXCLK 125
GTXCLK 125
----TX PLL 25
--TX PLL 2.5
-RX PLL 62.5b
---
Table 6-19. Timing Path Muxes – DLB Loopback
TX Rate
TXCLK
Mode
Buffer Mux
Mux/Driver
GMII
RGMII 1000
RGMII 100
RGMII 10
MII 100 - DCE
MII 100 - DTE
GTXCLK 125
GTXCLK 125
GTXCLK 25
GTXCLK 2.5
TX PLL 25
TXCLK 25
----TX PLL 25
---
RX PCS
Mux
RX Rate
Buffer Mux
RXCLK
Driver
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 125
RX PLL 125
RX PLL 25
RX PLL 2.5
RX PLL 25
RXCLK 25
RX PLL 2.5
RXCLK 2.5
RX PLL 62.5a
RX PLL 125
RX PLL 125
RX PLL 125
RX PLL 125
RX PLL 25
RX PLL 2.5
RX PLL 25
--RX PLL 2.5
--RX PLL 62.5a
RX PLL 125
RX PLL 125
RX PCS
Mux
RX Rate
Buffer Mux
RXCLK
Driver
TX PLL 62.5
TX PLL 62.5
TX PLL 62.5
TX PLL 62.5
TX PLL 62.5
TX PLL 62.5
TX PLL 125
TX PLL 125
TX PLL 25
TX PLL 2.5
TX PLL 25
TXCLK 25
TX PLL 125
TX PLL 125
TX PLL 25
TX PLL 2.5
TX PLL 25
---
36
_________________________________________________________________________________________________ MAX24287
Mode
TX Rate
Buffer Mux
TXCLK
Mux/Driver
RX PCS
Mux
RX Rate
Buffer Mux
RXCLK
Driver
MII 10 - DCE
MII 10 - DTE
TBI half rate
TBI full rate
RTBI
TX PLL 2.5
TXCLK 2.5
GTXCLK 125
GTXCLK 125
GTXCLK 125
TX PLL 2.5
--TX PLL 62.5b
---
TX PLL 62.5
TX PLL 62.5
TX PLL 62.5
TX PLL 62.5
TX PLL 62.5
TX PLL 2.5
TXCLK 2.5
TX PLL 62.5a
TX PLL 125
TX PLL 125
TX PLL 2.5
--TX PLL 62.5a
TX PLL 125
TX PLL 125
RX PCS
Mux
RX Rate
Buffer Mux
RXCLK
Driver
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 62.5
RX PLL 125
RX PLL 125
RX PLL 25
RX PLL 2.5
RX PLL 25
RXCLK 25
RX PLL 2.5
RXCLK 2.5
RX PLL 125
RX PLL 125
RX PLL 25
RX PLL 2.5
RX PLL 25
--RX PLL 2.5
--
Table 6-20. Timing Path Muxes – RLB Loopback
TX Rate
TXCLK
Mode
Buffer Mux
Mux/Driver
GMII
RGMII 1000
RGMII 100
RGMII 10
MII 100 - DCE
MII 100 - DTE
MII 10 - DCE
MII 10 - DTE
RX PLL 125
RX PLL 125
RX PLL 25
RX PLL 2.5
RX PLL 25
RXCLK 25
RX PLL 2.5
RXCLK 2.5
----TX PLL 25
--TX PLL 2.5
--
6.9.1 RX PLL
The RX PLL is used to recover the clock from the RDP/RDN high-speed serial input signal. It generates 625MHz
for the de-serializer and 125MHz, 62.5MHz, 25MHz and 2.5MHz for the receive-side PCS decoder, rate adaption
buffer and parallel port logic. It also generates a loss of lock (RLOL) signal for the IR.RLOL latched status bit.
6.9.2 TX PLL
The TX PLL generates a low-jitter 625MHz clock signal for the serializer and the TCLKP/TCLKN differential output.
This clock signal meets the jitter requirements of IEEE802.3. It also generates 125MHz, 62.5MHz, 25MHz and
2.5MHz for the transmit-side PCS decoder, rate adaption buffer and parallel port logic.
The TX PLL locks to the REFCLK signal, which can be 125MHz, 25MHz, 12.8MHz or 10MHz as specified by the
RXD[3:2] pins during device reset. The 12.8MHz and 10MHz frequencies enable the device to share an oscillator
with any clock synchronization ICs that may be on the same board.
6.9.3 Input Jitter Tolerance
The input jitter tolerance is specified at the receive serial input RDP/RDN. The MAX24287 CDR block accepts data
with maximum total jitter up to 0.75 UI (or 600 ps) peak-to-peak as required by 802.3 Table 38-10 and as shown in
Table 9-8. Total jitter is composed of both deterministic and random components. The allowed random jitter equals
the allowed total jitter minus the actual deterministic jitter at RDP/RDN.
6.9.4
Output Jitter Generation
The output jitter generation limit is specified at the transmit serial output (TDP/TDN) of the serializer. According to
Table 38-10 of IEEE 802.3, the maxim total jitter generated must be less than 0.24 UI (192 ps) peak-to-peak and
the deterministic jitter should be less than 0.10 UI (80 ps) peak-to-peak. MAX24287 typical and maximum jitter
generation specifications are shown in Table 9-10. Actual output jitter performance is a function of REFCLK signal
jitter. Contact the factory for a tool to calculate output jitter from REFCLK phase noise.
6.9.5
TX PLL Jitter Transfer
The TX PLL has a bandwidth of approximately 200kHz and jitter transfer peaking of 0.1dB or less.
37
_________________________________________________________________________________________________ MAX24287
6.9.6
GPIO Pins as Clock Outputs
Reference Clock. A 125MHz clock from the TX PLL (locked to the REFCLK signal) can be output on one or more
GPIO pins. See section 6.2 for configuration details. One use for this 125MHz output is to provide a 125MHz
transmit clock to a MAC block on a neighboring component. The MAC then uses this signal to clock its transmit
parallel MII pins.
Recovered Clock. A 25MHz or 125MHz clock signal from the receive clock and data recovery PLL can be output
on one or more GPIO pins. This clock signal is typically used in synchronous Ethernet applications to send
recovered Ethernet line timing to the system's central timing function. See section 6.2 for configuration details.
These output clock signals do not glitch during internal switching between frequencies or sources or when being
squelched and unsquelched.
6.10 Loopbacks
Three loopbacks are available in the MAX24287. The loopback data paths are shown in the block diagram in
Figure 2-1. The clocking paths are shown in section 6.9.
6.10.1 Diagnostic Loopback
Diagnostic loopback is enabled by setting BMCR.DLB=1. When the parallel interface is GMII, RGMII or MII, the
PCS decoder in the receive path takes 10-bit codes from the PCS encoder in the transmit path rather than from the
deserializer. In these modes the rate adaption buffers are in the path, and therefore the receive clock can be
different than the transmit clock.
When the parallel interface is TBI or RTBI, 10-bit codes from the transmit side of the parallel interface are looped
back to the receive side of the parallel interface. In these modes the PCS encoder and decoder blocks perform a
simple pass-through function of 10-bit codes. The single 125MHz receive clock or dual 62.5MHz receive clocks are
derived from the signal on the GTXCLK pin.
During diagnostic loopback, if CR.DLBDO=0 the TDP/TDN output driver is placed in a high-impedance state and
the TDP/TDN pins are both pulled up to 3.3V by their internal 50Ω termination resistors. The TCLKP/TCLKN output
continues to toggle if enabled. If CR.DLBDO=1 then data is transmitted on TDP/TDN during diagnostic loopback
while also being looped back to the receiver.
During diagnostic loopback, the COL signal remains deasserted at all times, unless BMCR.COL_TEST is set, in
which case the COL signal behaves as described in 802.3 section 22.2.4.1.9.
6.10.2 Terminal Loopback
Terminal loopback is enabled by setting PCSCR.TLB=1. When this loopback is enabled, the receive CDR takes
serial data from the transmit driver rather than from the RDP/RDN pins. This loopback implements the EWRAP
function specified in 802.3 section 36.3.3 for the TBI interface.
During terminal loopback, if CR.TLBDO=0 the TDP/TDN output driver is placed in a high-impedance state, and the
TDP/TDN pins are both pulled up to 3.3V by their internal 50Ω termination resistors. The TCLKP/TCLKN output
continues to toggle if enabled. If CR.TLBDO=1 then data is transmitted on TDP/TDN during terminal loopback
while also being looped back to the receiver.
6.10.3 Remote Loopback
Remote loopback is enable by setting GMIICR.RLB=1. When this loopback is enabled, the transmit parallel
interface logic takes data from the receive parallel interface logic rather than from the transmit parallel interface
38
_________________________________________________________________________________________________ MAX24287
pins. During remote loopback the rate adaption buffers, PCS encoder and decoder, and PCS auto-negotiation
function all operate normally.
Loopback control bits BMCR.DLB and PCSCR.TLB must be set to zero for correct remote loopback operation. RLB
cannot be used in TBI or RTBI mode unless the receive signal on RDP/RDN is frequency locked to the REFCLK
signal. If the two signals are not frequency locked the rate adaption buffers will repeatedly overflow and reset
causing data errors.
During remote loopback, if CR.RLBDO=0 the receive parallel interface pins RXD, RX_DV, RX_ER, CRS and COL
are all driven low. If CR.RLBDO=1 then receive data and control information are output on these pins while also
being looped back to the transmitter.
6.11 Diagnostic and Test Functions
Transmit PCS Pattern Generator. The PCS encoder has a built-in pattern generator block. These patterns
provide different types of jitter in order to test the performance of a downstream PHY receiver. When
JIT_DIAG.JIT_EN=1, the PCS encoder outputs 10-bit codes from the jitter pattern generator rather than from the
8B/10B encoding logic. The pattern to be generated is specified by JIT_DIAG.JIT_PAT. Patterns include low-,
mixed- and high-frequency test patterns from 802.3 Annex 36A as well as a custom 10-bit pattern from the
JIT_DIAG.CUST_PAT register field.
When JIT_EN is set to 1, pattern generation starts and packet transmission stops immediately. This can cut off the
tail end of the packet currently being transmitted and can also cause a running disparity error. When JIT_EN is set
to 0, pattern generation stops and packet transmission starts immediately. This can result in the transmission of
only the tail end of a packet and can also cause a running disparity error.
6.12 Data Path Latencies
The MAX24287 data path latencies are shown in Table 6-21 below. These latencies exceed the full-duplex delay
constraints in 802.3 Table 36-9b. Therefore MAX24287 may not be compatible with PAUSE operation as specified
in 802.3 Clause 31.
Table 6-21. GMII Data Path Latencies
Event
TX_EN=1 sampled to 1st bit of /S/ on TDP/TDN
1st bit of /T/ on RDP/RDN to RX_DV deassert
Min, ns
119
211
Max, ns
121
216
802.3 Max,
ns (#bit times)
108.8 (136)
153.6 (192)
6.13 Board Design Recommendations
The receive CDR block requires a stable clock signal on the REFCLK pin. To prevent oscillator start-up noise
affecting the CDR, Maxim recommends that the REFCLK signal be held low during MAX24287 reset. When the
REFCLK signal comes from a local oscillator, the easiest way to achieve this is to wire the MAX24287 RST_N
signal to the enable pin on the oscillator as shown in Figure 6-11 below. If the oscillator does not have an enable
pin, then the output of the oscillator can be ANDed with the RST_N signal.
39
_________________________________________________________________________________________________ MAX24287
Figure 6-11. Recommended REFCLK Oscillator Wiring
MAX24287
RST_N
RST_N
REFCLK
Oscillator
EN
OUT
10k
40
_________________________________________________________________________________________________ MAX24287
7. Register Descriptions
The device registers can be accessed through the MDIO interface, which is part of the parallel MII interface.
Registers at addresses 16 to 30 are paged using the PAGESEL.PAGE register field. Register addresses 0 to 15
and 31 are not paged and remain the same regardless of the value of PAGESEL.PAGE. Nonexistent registers are
not writable and read back as high impedance.
7.1
Register Map
Table 7-1. Register Map
MDIO
Register
Register Name
Address
0
BMCR
1
BMSR
2
ID1
3
ID2
4
AN_ADV
5
AN_RX
6
AN_EXP
15
EXT_STAT
P0.16
JIT_DIAG
P0.17
PCSCR
P0.18
GMIICR
P0.19
CR
P0.20
IR
P1.16
ID
P1.17
GPIOCR1
P1.18
GPIOCR2
P1.19
GPIOSR
31
PAGESEL
7.2
R/W
RW
RO
RO
RO
RW
RO
RO
RO
RW
RW
RW
RW
RW
RO
RW
RW
RO
RW
Register Descriptions
The register operating type is described in the “R/W” column using the following codes:
Type
RW
RO
SC
LH-E
LL-E
LH-C
LL-C
Description
Read-Write. Register field can be written and read back.
Read Only. Register field can only be read; writing it has no effect. Write 0 for future compatibility.
Self Clearing. Register bit self clears to 0 after being written as 1
Latch High—Event. Bit latches high when the internal event occurs and returns low when it is read.
Latch Low—Event. Bit latches low when the internal event occurs and returns high when it is read.
Latch High—Condition. Bit latches high when the internal condition is present. If the condition is still
present when the bit is read then the bit stays high. If the condition is not present when the bit is read
then the bit returns low.
Latch Low—Condition. Bit latches low when the internal condition is present. If the condition is still
present when the bit is read then the bit stays low. If the condition is not present when the bit is read
then the bit returns high.
In the register definitions below, the register addresses are provided at the end of the table title, e.g. "(MDIO 0)" for
the BMCR register. Addresses 16 to 30 are bank-switched by the PAGESEL.PAGE field as shown in Table 7-1.
Addresses 0 to 15 and 31 are not bank-switched.
41
_________________________________________________________________________________________________ MAX24287
7.2.1 BMCR
Basic Mode Control Register (MDIO 0)
Bit(s)
Name
15
DP_RST
14
DLB
13
12
Reserved
AN_EN
11:10
9
Reserved
AN_START
8
7
Reserved
COL_TEST
6:0
Note 1:
Reserved
Description
R/W
Reset
Datapath Reset. This bit resets the entire datapath
from parallel MII through PCS. Self-clearing. See
section 6.3.1.
0 = normal operation
1 = reset
Diagnostic Loopback. Transmit data is looped
back to the receive path. See block diagram in
Figure 2-1 for the location of this loopback and see
section 6.10 for additional details.
0 = Disable diagnostic loopback (normal operation)
1 = Enable diagnostic loopback
Ignore on Read
Auto-negotiation enable. See section 6.7.
0 = Disable
1 = Enable
Ignore on Read
Setting this bit causes a restart of the Autonegotiation process. Self clears. See section 6.7.
Ignore on Read
Collision test. When this bit is set, MAX24287
asserts the COL signal within 64 parallel interface
transmit clock cycles after TX_EN is asserted and
deasserts the COL signal within one parallel
interface transmit clock cycle after TX_EN is
deasserted. See 802.3 section 22.2.4.1.9. See
section 6.10.1.
Ignore on Read
RW,
SC
0
RW
0
RO
RW
0
Note 1
RO
RW,
SC
RO
RW
0
0
RO
0
0
0
At reset when COL=1 or (RXD[1:0]!=11 and RX_DV=1) AN_EN is set to 1 else it is set to 0.
42
_________________________________________________________________________________________________ MAX24287
7.2.2 BMSR
Basic Mode Status Register (MDIO 1)
Bit(s)
Name
15
14
Reserved
SPD100FD
13
SPD100HD
12
SPD10FD
11
SPD10HD
10:9
8
Reserved
EXT_STAT
7
6
Reserved
MF_PRE
5
AN_COMP
4
RFAULT
3
AN_ABIL
2
LINK_ST
1
0
Reserved
EXT_CAP
Description
R/W
Reset
Ignore on read
100BASE-X Full Duplex capability.
Always indicates 1 = able to do 100BASE-X full duplex
100BASE-X Half Duplex capability
Always indicates 1 = able to do 100BASE-X half duplex
10Mb/s Full Duplex capability
Always indicates 1 = able to do 10Mb/s full duplex
10Mb/s Half Duplex capability
Always indicates 1 = able to do 10Mb/s half duplex
Ignore on read
Extended Status information available
Always indicates 1 = extended status information in
EXT_STAT register
Ignore on Read
Management preamble suppression supported
Always indicates 1 = MDIO preamble suppression is
supported.
Auto-negotiation Complete
0 = Auto-negotiation not completed or not in progress
1 = Auto-negotiation has completed
Remote Fault – Indicates presence of remote fault on link
partner. For SGMII, remote fault is latched high when the
ALOS input pin goes high or when the CDR indicates
receive loss-of-lock. For 1000BASE-X, remote fault is
RF≠00 in AN_RX. RFAULT is latched high when a remote
fault is detected. If no remote fault is detected when
RFAULT is read then RFAULT goes low. Otherwise
RFAULT remains unchanged. IR.RFAULT is a read-only
copy of this bit that can cause an interrupt when enabled.
0 = no remote fault has been detected since this bit was
last read
1 = remote fault has occurred since this bit was last read
Auto-negotiation Ability
Always indicates 1 = able to perform Auto-negotiation
Link Status – Indicates the status of the physical
connection to the link partner. LINK_ST is latched low
when the link goes down. If the PCS state machine is in
the link-up state when LINK_ST is read then LINK_ST
goes high. Otherwise LINK_ST remains unchanged.
IR.LINK_ST is a read-only copy of this bit that can cause
an interrupt when enabled.
0 = link down has occurred since this bit was last read
1 = link has been up continuously since this bit was last
read
Ignore on Read
Extended Register Capability
Always indicates 1 = the extended registers exist
RO
RO
0
1
RO
1
RO
1
RO
1
RO
RO
0
1
RO
RO
0
1
RO
0
RO,
LH-C
0
RO
1
RO,
LL-C
0
RO
RO
0
1
43
_________________________________________________________________________________________________ MAX24287
7.2.3 ID1 and ID2
Registers ID1 and ID2 are set to all zeroes as allowed by clause 22.2.4.3.1 of IEEE 802.3. The actual device ID
can be read from the ID register.
Device ID 1 Register (MDIO 2)
Bit(s)
15:0
Name
OUI_HI
Description
OUI[3:18]
R/W
Reset
RO
0
R/W
Reset
Device ID 2 Register (MDIO 3)
Bit(s)
Name
Description
15:10
OUI_LI
OUI[19:24]
RO
0
9:4
MODEL
MODEL[5:0] Model Number
RO
0
3:0
REV
REV[3:0] Revision Number
RO
0
44
_________________________________________________________________________________________________ MAX24287
7.2.4 AN_ADV
The register contents are transmitted to the link partner’s AN_RX register.
The fields of this register have different functions depending on whether the device is in 1000BASE-X autonegotiation mode or in SGMII control information transfer mode. See section 6.7 for details.
Auto-Negotiation Advertisement Register (MDIO 4)
Bit(s)
15
14
13:0
Name
Description
AN_ADV[15] (NP_LK)
AN_ADV[14]
AN_ADV[13:0]
See section 6.7 for details.
Ignore on read
See section 6.7 for details.
R/W
Reset
RW
RO
RW
Note 1
0
Note 1
Note 1: The reset value of the bits of this register depend on the values of configuration pins at reset, as shown below. See section 6.1.
Configuration Pin Settings at Reset
COL=0, RX_DV=0
COL=0, RX_DV=1, RXD[1]=0
COL=0, RX_DV=1, RXD[1]=1, GPO2=0
COL=0, RX_DV=1, RXD[1]=1, GPO2=1
COL=1, GPO2=0
COL=1, GPO2=1
Configuration Description
No auto-negotiation
15-pin config mode, SGMII 10 or 100Mbps
15-pin config mode, SGMII 1000Mbps
15-pin config mode, 1000BASE-X
3-pin config mode, SGMII 1000Mbps
3-pin config mode, 1000BASE-X
AN_ADV[15:0] Reset Value
0000 0000 0000 0000
1001 0R00 0000 0001 (R = RXD[0] pin value)
1001 1000 0000 0001
0000 0000 0010 0000
1001 1000 0000 0001
0000 0000 0010 0000
7.2.5 AN_RX
The rx_Config_Reg[15:0] value received from the link partner is stored in this register.
This fields of this register have different functions depending on whether the device is in 1000BASE-X autonegotiation mode or in SGMII control information transfer mode. See section 6.7 for details.
Auto-Negotiation Link Partner Ability Receive Register (MDIO 5)
Bit(s)
Name
15
14
NP
Acknowledge
13:0
ABILITY
Description
See section 6.7 for details
1= link partner successfully received the transmitted base
page.
See section 6.7 for details
R/W
Reset
RO
RO
0
0
RO
0
R/W
Reset
RO
RO
0
0
RO,
LH-E
0
RO
0
7.2.6 AN_EXP
This register is used to indicate that a new link partner abilities page has been received.
Auto-negotiation Extended Status Register (MDIO 6)
Bit(s)
Name
15:3
2
Reserved
NP
1
PAGE
0
Reserved
Description
Ignore on Read
Next Page capability - This device does not support next
pages, it always reads as 0.
Page received, clears when read. See section 6.7.
0 = No new AN_RX page from link partner
1 = New AN_RX page from Link partner is ready
Ignore on Read
45
_________________________________________________________________________________________________ MAX24287
7.2.7 EXT_STAT
Extended Status Register (MDIO 15)
Bit(s)
Name
15
1000X_FDX
14
1000X_HDX
13:0
Reserved
7.2.8
JIT_DIAG
Description
1000BASE-X Full Duplex capability.
Always indicates 1 = able to do 100BASE-X full duplex
1000BASE-X Half Duplex capability.
Always indicates 0 = not able to do 100BASE-X half duplex
Ignore on Read
R/W
Reset
RO
1
RO
0
RO
0
R/W
Reset
RW
0
RW
0
RO
RW
0
0
Jitter Diagnostics Register (MDIO 0.16)
Bit(s)
Name
15
JIT_EN
14:12
JIT_PAT
Description
Jitter Pattern Enable.
Enables jitter pattern to be transmitted instead of normal
data on TDP/TDN.
0 = Transmit normal data patterns from PCS encoder
1 = Transmit jitter test pattern specified by JIT_PAT
Jitter Pattern. Specifies the pattern to transmit. Includes
standard patterns specified in IEEE 802.3 Annex 36A.
JIT_PAT
000
001
010
011
100
101
110
111
11:10
9:0
Reserved
CUST_PAT
Pattern
Custom pattern defined in CUST_PAT[9:0]
802.3 Annex 36A.4 high frequency test pattern
1010101010…
802.3 Annex 36A.3 mixed frequency test
pattern
1111101011 0000010100…
Low frequency pattern
1111100000…
"Random" jitter pattern
0011111010 1001001100 1010011100
1100010101…
802.3 Annex 36A.2 low frequency test pattern
1111100000…
Reserved
Reserved
.
Write as 0, Ignore on Read
CUST_PAT[9:0] Custom 10-bit repeating pattern used when
JIT_PAT=000. The transmission order is LSB(0) to MSB(9).
46
_________________________________________________________________________________________________ MAX24287
7.2.9 PCSCR
PCS Control Register (MDIO 0.17)
Bit(s)
Name
15
14
Reserved
TIM_SHRT
13
DYRX_DIS
12
DYTX_DIS
11:7
6
Reserved
WD_DIS
5
4
Reserved
BASEX
3:2
1
Reserved
TLB
0
EN_CDET
Note 1:
Description
R/W
Reset
Ignore on read
When PCSCR.BASEX=1 (1000BASE-X mode), this bit can
be used to shorten the link timer timeout from 10ms to
1.6ms. The normal 10ms setting is called for in the 802.3
standard. When BASEX=0 this bit is ignored.
0 = PCS link timer has normal timeout
1 = PCS link timer has 1.6ms timeout
Disable Receive PCS Running Disparity.
0 = Enable PCS receive running disparity (normal)
1 = Disable PCS receive running disparity
Disable Transmit PCS Running Disparity.
0 = Enable PCS transmit running disparity (normal)
1 = Disable PCS transmit running disparity
Write as 0, Ignore on Read
Disable auto-negotiation watchdog timer. See section 6.7.
0 = Restart auto-negotiation after 5 seconds if link not up
after previous start or restart
1 = Disable auto-negotiation watchdog restart
Ignore on Read
Specifies 1000BASE-X PCS mode or SGMII PCS mode. See
section 6.7.
0 = SGMII PCS mode selected, link timer = 1.6 ms
1 = 1000BASE-X PCS mode selected, link timer = 10 ms
(or 1.6ms when PCSCR.TIM_SHRT=1)
Write as 0, Ignore on Read
Terminal Loopback. Transmit data is looped back to the
receive path at the high-speed serial interface (TDP/TDN to
RDP/RDN). See block diagram in Figure 2-1 for the location
of this loopback and see section 6.10 for additional details.
0 = Disable terminal loopback (normal operation)
1 = Enable terminal loopback
Enable comma detection and code group alignment in the
ingress path. See section 6.6.2.5.
0 = Disable comma alignment
1 = Enable comma alignment (normal operation)
RO
RW
0
0
RW
0
RW
0
RO
RW
0
0
RO
RW
0
Note 1
RO
RW
0
0
RW
1
At reset, if COL=1 or RXD[1] = 1 then BASEX is set to the value of the GPO2 pin, else BASEX is set to 0. In other words, in 3-pin
configuration mode OR (15-pin configuration mode AND parallel interface is set to 1000Mbps) BASEX is set to the value of the GPO2
pin. Otherwise BASEX is set to 0.
47
_________________________________________________________________________________________________ MAX24287
7.2.10 GMIICR
GMII Interface Control Register (MDIO 0.18)
Bit(s)
Name
15:14
SPD[1:0]
13
TBI_RATE
12
DTE_DCE
11
DDR
10
TXCLK_EN
9:8
7
Reserved
Reserved
6:4
3
Reserved
REF_INV
2:1
0
Reserved
RLB
Note 1:
Note 2:
Note 3:
Note 4:
Description
R/W
Reset
Selects parallel MII interface mode. See section 6.6.
Bus mode
SPD
Speed
DDR=0
DDR=1
00
10 Mbps
MII
RGMII-10
01
100 Mbps
MII
RGMII-100
10
1000 Mbps
GMII
RGMII-1000
11
1000 Mbps
TBI
RTBI
Select TBI bus receive clock mode. Used when
SPD[1:0]=11; ignored otherwise. See section 6.6.2.
0 = TBI with one 125MHz receive clock (RXCLK pin)
1 = Normal TBI interface: dual 62.5MHz clocks on RXCLK
and TXCLK/RXCLK1 pins, 180 degrees out of phase
DTE-DCE mode selection for MII bus mode. Used when
SPD[1:0]=0x and DDR=0; ignored otherwise. See section
6.6.5.
1 = MII-DTE (MAX24287 on MAC side of MII, both RXCLK
and TXCLK are inputs)
0 = MII-DCE (MAX24287 on PHY side of MII, both RXCLK
and TXCLK are outputs)
Reduced pin count (RGMII or RTBI) using double data rate,
i.e. data sampling/updating on both edges of the clock. See
the SPD[1:0] description above and section 6.6.
0 = MII, GMII or TBI bus mode
1 = RGMII or RTBI bus mode
In GMII, RGMII and RTBI modes and in TBI mode with one
125MHz receive clock, the TXCLK pin is not used for parallel
interface operation. The TXCLK_EN bit enables TXCLK to
output a 125MHz clock from the TX PLL in those modes.
TXCLK_EN is ignored in MII mode and normal TBI mode.
See section 6.6.
0 = TXCLK pin is high impedance
1 = TXCLK pin outputs 125MHz clock
Write as 0, ignore on Read
Write as 1, ignore on Read
RW
Note 1
RW
Note 2
RW
Note 3
RW
Note 4
RW
Note 5
RO
RW
0
1
Write as 0, ignore on Read
REFCLK Invert control.
0 = Noninverted
1 = Inverted
Write as 0, ignore on Read
Remote Loopback. Receive data is looped back to the
transmit path. See block diagram in Figure 2-1 for the
location of this loopback and see section 6.10 for additional
details.
0 = Disable remote loopback (normal operation)
1 = Enable remote loopback
RO
RW
0
0
RO
RW
0
0
At reset if COL=0 then SPD[1:0] is set to the value on the RXD[1:0] pins, else SPD[1:0] is set to 10. In other words, in 15-pin
configuration mode SPD[1:0] is set to the value on the RXD[1:0] pins. In 3-pin configuration mode SPD[1:0] is set to 10 (1000Mbps).
At reset if COL=0 the TBI_RATE bit is set to the value on the RX_DV pin, else TBI_RATE is set to 0. In other words, in 15-pin
configuration mode the TBI_RATE bit is set to the value on the RX_DV pin. In 3-pin configuration mode TBI_RATE is set to 0.
At reset if COL=0 and RXD[1] = 0 the DTE_DCE bit is set to the value on the GPO2 pin, else DTE_DCE is set to 0. In other words, in
15-pin configuration mode when the parallel interface is configured for 10Mbps or 100Mbps the DTE_DCE bit is set to the value on
the GPO2 pin. Otherwise the DTE_DCE bit is set to 0.
At reset the DDR bit is set to the value on the CRS pin.
48
_________________________________________________________________________________________________ MAX24287
Note 5:
At reset if COL=0 the TXCLK_EN bit is set to the value on the TXCLK pin, else TXCLK_EN is set to 1. In other words, in 15-pin
configuration mode the TXCLK_EN bit is set to the value on the TXCLK pin. In 3-pin configuration mode TXCLK_EN is set to 1.
7.2.11 CR
Control Register (MDIO 0.19)
Bit(s)
Name
15:13
Reserved
12
DLBDO
11
RLBDO
10
TLBDO
9
RCFREQ
8
RCSQL
7:6
Reserved
5
TCLK_EN
4:0
Reserved
Description
R/W
Reset
Write as 0, Ignore on Read
RO
0
Diagnostic Loopback Data Out. Set this bit to enable transmit data to
be output on the serial interface during diagnostic loopback (i.e.
when BMCR.DLB=1). See section 6.10.
Remote Loopback Data Out. Set this bit to enable receive data to be
output on the parallel interface during remote loopback (i.e. when
GMIICR.RLB=1). See section 6.10.
Terminal Loopback Data Out. Set this bit to enable transmit data
(rather than zeros) to be output on the serial interface during
terminal loopback (i.e. when PCSCR.TLB=1). See section 6.10.
Specifies which recovered clock frequency to output on a GPIO pin.
See section 6.2.
0 = 25MHz
1 = 125MHz
Set this bit to squelch the recovered clock on GPO2, GPIO2 and
GPIO4-7 when any of several squelch conditions occur. See
sections 6.2.1.
0 = Recovered clock output not squelched
1 = Recovered clock squelched when a squelch condition occurs
Write as 0, Ignore on Read
RW
0
RW
0
RW
0
RW
0
RW
0
RO
0
Serial interface transmit clock output enable. See section 6.5.
0 = Disable TCLKP/TCLKN
1 = Enable TCLKP/TCLKN
Write as 0, Ignore on Read
RW
0
RO
0
49
_________________________________________________________________________________________________ MAX24287
7.2.12 IR
This register contains both latched status bits and interrupt enable bits. When the latched status bit is active and
the associated interrupt enable bit is set an interrupt signal can be driven onto one of the GPIO pins by configuring
the GPIOCR1 register.
Interrupt Register 1 (MDIO 0.20)
Bit(s)
Name
Description
R/W
Reset
15:14
Reserved
Write as 0, Ignore on Read
RO
0
13
RFAULT_IE
RO
0
12
LINK_ST_IE
RO
0
11
ALOS_IE
RW
0
10
PAGE _IE
RW
0
9
RLOL_IE
RW
0
8
RLOS_IE
RW
0
7:6
5
Reserved
RFAULT
RO
RO
0
0
4
LINK_ST
RO
0
3
ALOS
RO,
LH-C
0
2
PAGE
RO
0
1
RLOL
RO,
LH-C
0
0
RLOS
Interrupt Enable for RFAULT.
0 = interrupt disabled
1 = interrupt enabled
Interrupt Enable for LINK_ST.
0 = interrupt disabled
1 = interrupt enabled
Interrupt Enable for ALOS. See section 6.5.
0 = interrupt disabled
1 = interrupt enabled
Interrupt Enable for PAGE. See section 6.7.
0 = interrupt disabled
1 = interrupt enabled
Interrupt Enable for RLOL. See section 6.5.
0 = interrupt disabled
1 = interrupt enabled
Interrupt Enable for RLOS. See section 6.5.
0 = interrupt disabled
1 = interrupt enabled
Write as 0, Ignore on Read
Remote Fault. This is a read-only copy of BMSR.RFAULT.
An interrupt is generated when RFAULT=1 and
RFAULT_IE=1.
Link Status. This is a read-only copy of BMSR.LINK_ST
(active low). An interrupt is generated when LINK_ST=0
and LINK_ST_IE=1.
Analog Loss-of-Signal latched status bit. Set when ALOS
input pin goes high. An interrupt is generated when
ALOS=1 and ALOS_IE=1. See section 6.5.
0 = Defect not detected since last read
1 = Defect detected since last read
This is a read-only copy of AN_EXP.PAGE. An interrupt is
generated when PAGE=1 and PAGE_IE=1. See section
6.7.
0 = Defect not detected since last read
1 = Defect detected since last read
Receive CDR Loss-of-Lock latched status bit. Set when
the CDR PLL loses lock. An interrupt is generated when
RLOL=1 and RLOL_IE=1. See section 6.9.1.
0 = Defect not detected since last read
1 = Defect detected since last read
Receive CDR Loss-of-Signal latched status bit. Set when
the CDR block sees no transitions in the incoming signal
for 24 consecutive bit times. See section 6.5.
0 = Defect not detected since last read
1 = Defect detected since last read
RO,
LH-C
0
50
_________________________________________________________________________________________________ MAX24287
7.2.13 PAGESEL
This page select register is used to extend the MDIO register space by mapping 1 of 2 pages of 15 registers into
MDIO register addresses 16 to 30. PAGESEL also has a global interrupt status bit. This register is available on all
pages at MDIO register address 31.
Page Register (MDIO 31, on all pages)
Bit(s)
Name
Description
R/W
Reset
15
TEST
Factory Test. Always write 0.
RW
0
14
Reserved
Ignore on Read
RO
0
13
IR
RO
0
12:2
Reserved
Interrupt from IR register. This bit is set if any latched status bit
and its associated interrupt enable bit are both active in the IR
register. See section 6.3.2.
0 = interrupt source not active
1 = interrupt source is active
Ignore on Read
RO
0
1:0
PAGE[1:0]
RW
00
Page selection for MDIO register addresses 16 to 30. See
section 7.
00 = PHY extended register page 0
01 = PHY extended register page 1
10, 11 = unused values
51
_________________________________________________________________________________________________ MAX24287
7.2.14 ID
The ID register matches the JTAG device ID (lower 12 bits) and revision (all 4 bits).
Device ID Register (MDIO 1.16)
Bit(s)
Name
Description
R/W
Reset
15:12
REV
REV[3:0] Device revision number. Contact factory for value.
RO
Note 1
11:0
DEVICE
DEVICE[11:0] Device ID
RO
Note 1
Description
R/W
Reset
Global device reset. Pin states are sampled and used to set
the default values of several register fields. See section 6.3.1.
0 = normal operation
1 = reset
GPO1 output pin mode selection. See Table 6-4.
GPO2 output pin mode selection. See Table 6-5.
GPIO1 output pin mode selection. See Table 6-4.
GPIO2 output pin mode selection. See Table 6-5.
GPIO3 output pin mode selection. See Table 6-4.
RW,
SC
0
RW
RW
RW
RW
RW
Note 2
Note 2
Note 1
000
000
Note 1: See Device Code in Table 8-2.
7.2.15 GPIOCR1
GPIO Control Register 1 (MDIO 1.17)
Bit(s)
Name
15
RST
14:12
11:9
8:6
5:3
2:0
GPO1_SEL[2:0]
GPO2_SEL[2:0]
GPIO1_SEL[2:0]
GPIO2_SEL[2:0]
GPIO3_SEL[2:0]
Note 1:
Note 2:
At reset if COL=0 and GPO1=1 the GPIO1_SEL bits are set to 100 (125MHz), else the bits are set to 000 (high impedance).
At reset if COL=0 and RXD[1:0]=11 (TBI or RTBI) the bits are set to 000, else the bits are set to 110.
7.2.16 GPIOCR2
GPIO Control Register 2 (MDIO 1.18)
Bit(s)
Name
15:14
13
Reserved
GPIO47_LSC
12
GPIO13_LSC
11:9
8:6
5:3
2:0
GPIO7_SEL[2:0]
GPIO6_SEL[2:0]
GPIO5_SEL[2:0]
GPIO4_SEL[2:0]
Description
Ignore on Read
GPIO4-7 Latched Status Control. This bit controls the
behavior of latched status bits GPIO4L through GPIO7L in
GPIOSR. See section 6.2.
0 = Set latched status bit when input goes low
1 = Set latched status bit when input goes high
GPIO1-3 Latched Status Control. This bit controls the
behavior of latched status bits GPIO1L through GPIO3L in
GPIOSR. See section 6.2.
0 = Set latched status bit when input goes low
1 = Set latched status bit when input goes high
GPIO7 output pin mode selection. See Table 6-6.
GPIO6 output pin mode selection. See Table 6-6.
GPIO5 output pin mode selection. See Table 6-6.
GPIO4 output pin mode selection. See Table 6-6.
R/W
Reset
RO
RW
0
0
RW
0
RW
RW
RW
RW
000
000
000
000
52
_________________________________________________________________________________________________ MAX24287
7.2.17 GPIOSR
GPIO Status Register (MDIO 1.19)
Bit(s)
Name
15
14
Reserved
GPIO7L
13
GPIO6L
12
GPIO5L
11
GPIO4L
10
GPIO3L
9
GPIO2L
8
GPIO1L
7
6
Reserved
GPIO7
5
GPIO6
4
GPIO5
3
GPIO4
2
GPIO3
1
GPIO2
0
GPIO1
Description
Ignore on Read
GPIO7 latched status. Set when the transition specified by
GPIOCR2.GPIO47_LSC occurs on the GPIO7 pin.
0 = Transition did not occur since this bit was last read
1 = Transition did occur since this bit was last read
GPIO6 latched status. Set when the transition specified by
GPIOCR2.GPIO47_LSC occurs on the GPIO6 pin.
0 = Transition did not occur since this bit was last read
1 = Transition did occur since this bit was last read
GPIO5 latched status. Set when the transition specified by
GPIOCR2.GPIO47_LSC occurs on the GPIO5 pin.
0 = Transition did not occur since this bit was last read
1 = Transition did occur since this bit was last read
GPIO4 latched status. Set when the transition specified by
GPIOCR2.GPIO47_LSC occurs on the GPIO4 pin.
0 = Transition did not occur since this bit was last read
1 = Transition did occur since this bit was last read
GPIO3 latched status. Set when the transition specified by
GPIOCR2.GPIO13_LSC occurs on the GPIO3 pin.
0 = Transition did not occur since this bit was last read
1 = Transition did occur since this bit was last read
GPIO2 latched status. Set when the transition specified by
GPIOCR2.GPIO13_LSC occurs on the GPIO2 pin.
0 = Transition did not occur since this bit was last read
1 = Transition did occur since this bit was last read
GPIO1 latched status. Set when the transition specified by
GPIOCR2.GPIO13_LSC occurs on the GPIO1 pin.
0 = Transition did not occur since this bit was last read
1 = Transition did occur since this bit was last read
Ignore on Read
GPIO7 pin real time status. See section 6.2.
0 = Pin low
1 = Pin high
GPIO6 pin real time status.
0 = Pin low
1 = Pin high
GPIO5 pin real time status.
0 = Pin low
1 = Pin high
GPIO4 pin real time status.
0 = Pin low
1 = Pin high
GPIO3 pin real time status.
0 = Pin low
1 = Pin high
GPIO2 pin real time status.
0 = Pin low
1 = Pin high
GPIO1 pin real time status.
0 = Pin low
1 = Pin high
R/W
Reset
RO
RO,
LH-E
0
0
RO,
LH-E
0
RO,
LH-E
0
RO,
LH-E
0
RO,
LH-E
0
RO,
LH-E
0
RO,
LH-E
0
RO
RO
0
0
RO
0
RO
0
RO
0
RO
0
RO
0
RO
0
53
_________________________________________________________________________________________________ MAX24287
8. JTAG and Boundary Scan
8.1 JTAG Description
The MAX24287 supports the standard instruction codes SAMPLE/PRELOAD, BYPASS, and EXTEST. Optional
public instructions included are HIGHZ, CLAMP, and IDCODE. Figure 8-1 shows a block diagram. The MAX24287
contains the following items, which meet the requirements set by the IEEE 1149.1 Standard Test Access Port and
Boundary Scan Architecture:
Test Access Port (TAP)
Bypass Register
TAP Controller
Boundary Scan Register
Instruction Register
Device Identification Register
The TAP has the necessary interface pins, namely JTCLK, JTRST_N, JTDI, JTDO, and JTMS. Details on these
pins can be found in Table 5-4. Details about the boundary scan architecture and the TAP can be found in
IEEE 1149.1-1990, IEEE 1149.1a-1993, and IEEE 1149.1b-1994.
Figure 8-1. JTAG Block Diagram
BOUNDARY
SCAN
REGISTER
MUX
DEVICE
IDENTIFICATION
REGISTER
BYPASS
REGISTER
INSTRUCTION
REGISTER
SELECT
TEST ACCESS PORT
CONTROLLER
50k
JTDI
50k
JTMS
ENABLE
50k
JTCLK
JTRST_N
JTDO
8.2 JTAG TAP Controller State Machine Description
This section discusses the operation of the TAP controller state machine. The TAP controller is a finite state
machine that responds to the logic level at JTMS on the rising edge of JTCLK. Each of the states denoted in Figure
8-2 are described in the following paragraphs.
Test-Logic-Reset. Upon device power-up, the TAP controller starts in the Test-Logic-Reset state. The instruction
register contains the IDCODE instruction. All system logic on the device operates normally.
Run-Test-Idle. Run-Test-Idle is used between scan operations or during specific tests. The instruction register and
all test registers remain idle.
54
_________________________________________________________________________________________________ MAX24287
Select-DR-Scan. All test registers retain their previous state. With JTMS low, a rising edge of JTCLK moves the
controller into the Capture-DR state and initiates a scan sequence. JTMS high moves the controller to the SelectIR-SCAN state.
Capture-DR. Data can be parallel-loaded into the test register selected by the current instruction. If the instruction
does not call for a parallel load or the selected test register does not allow parallel loads, the register remains at its
current value. On the rising edge of JTCLK, the controller goes to the Shift-DR state if JTMS is low or to the Exit1DR state if JTMS is high.
Shift-DR. The test register selected by the current instruction is connected between JTDI and JTDO and data is
shifted one stage toward the serial output on each rising edge of JTCLK. If a test register selected by the current
instruction is not placed in the serial path, it maintains its previous state.
Exit1-DR. While in this state, a rising edge on JTCLK with JTMS high puts the controller in the Update-DR state,
which terminates the scanning process. A rising edge on JTCLK with JTMS low puts the controller in the Pause-DR
state.
Pause-DR. Shifting of the test registers is halted while in this state. All test registers selected by the current
instruction retain their previous state. The controller remains in this state while JTMS is low. A rising edge on
JTCLK with JTMS high puts the controller in the Exit2-DR state.
Exit2-DR. While in this state, a rising edge on JTCLK with JTMS high puts the controller in the Update-DR state
and terminates the scanning process. A rising edge on JTCLK with JTMS low puts the controller in the Shift-DR
state.
Update-DR. A falling edge on JTCLK while in the Update-DR state latches the data from the shift register path of
the test registers into the data output latches. This prevents changes at the parallel output because of changes in
the shift register. A rising edge on JTCLK with JTMS low puts the controller in the Run-Test-Idle state. With JTMS
high, the controller enters the Select-DR-Scan state.
Select-IR-Scan. All test registers retain their previous state. The instruction register remains unchanged during this
state. With JTMS low, a rising edge on JTCLK moves the controller into the Capture-IR state and initiates a scan
sequence for the instruction register. JTMS high during a rising edge on JTCLK puts the controller back into the
Test-Logic-Reset state.
Capture-IR. The Capture-IR state is used to load the shift register in the instruction register with a fixed value. This
value is loaded on the rising edge of JTCLK. If JTMS is high on the rising edge of JTCLK, the controller enters the
Exit1-IR state. If JTMS is low on the rising edge of JTCLK, the controller enters the Shift-IR state.
Shift-IR. In this state, the instruction register’s shift register is connected between JTDI and JTDO and shifts data
one stage for every rising edge of JTCLK toward the serial output. The parallel register and the test registers
remain at their previous states. A rising edge on JTCLK with JTMS high moves the controller to the Exit1-IR state.
A rising edge on JTCLK with JTMS low keeps the controller in the Shift-IR state, while moving data one stage
through the instruction shift register.
Exit1-IR. A rising edge on JTCLK with JTMS low puts the controller in the Pause-IR state. If JTMS is high on the
rising edge of JTCLK, the controller enters the Update-IR state and terminates the scanning process.
Pause-IR. Shifting of the instruction register is halted temporarily. With JTMS high, a rising edge on JTCLK puts
the controller in the Exit2-IR state. The controller remains in the Pause-IR state if JTMS is low during a rising edge
on JTCLK.
Exit2-IR. A rising edge on JTCLK with JTMS high puts the controller in the Update-IR state. The controller loops
back to the Shift-IR state if JTMS is low during a rising edge of JTCLK in this state.
Update-IR. The instruction shifted into the instruction shift register is latched into the parallel output on the falling
edge of JTCLK as the controller enters this state. Once latched, this instruction becomes the current instruction. A
55
_________________________________________________________________________________________________ MAX24287
rising edge on JTCLK with JTMS low puts the controller in the Run-Test-Idle state. With JTMS high, the controller
enters the Select-DR-Scan state.
Figure 8-2. JTAG TAP Controller State Machine
Test-Logic-Reset
1
0
Run-Test/Idle
1
Select
DR-Scan
1
0
1
Select
IR-Scan
0
0
1
1
Capture-DR
Capture-IR
0
0
Shift-DR
Shift-IR
0
0
1
1
1
Exit1- DR
1
Exit1-IR
0
0
Pause-DR
Pause-IR
0
0
1
0
1
0
Exit2-DR
Exit2-IR
1
1
Update-DR
1
0
Update-IR
1
0
8.3 JTAG Instruction Register and Instructions
The instruction register contains a shift register as well as a latched parallel output and is 3 bits in length. When the
TAP controller enters the Shift-IR state, the instruction shift register is connected between JTDI and JTDO. While in
the Shift-IR state, a rising edge on JTCLK with JTMS low shifts data one stage toward the serial output at JTDO. A
rising edge on JTCLK in the Exit1-IR state or the Exit2-IR state with JTMS high moves the controller to the UpdateIR state. The falling edge of that same JTCLK latches the data in the instruction shift register to the instruction
parallel output. Table 8-1 shows the instructions supported by the MAX24287 and their respective operational
binary codes.
Table 8-1. JTAG Instruction Codes
INSTRUCTIONS
SAMPLE/PRELOAD
BYPASS
EXTEST
CLAMP
HIGHZ
IDCODE
SELECTED REGISTER
Boundary Scan
Bypass
Boundary Scan
Bypass
Bypass
Device Identification
INSTRUCTION CODES
010
111
000
011
100
001
56
_________________________________________________________________________________________________ MAX24287
SAMPLE/PRELOAD. SAMPLE/RELOAD is a mandatory instruction for the IEEE 1149.1 specification. This
instruction supports two functions. First, the digital I/Os of the device can be sampled at the boundary scan
register, using the Capture-DR state, without interfering with the device’s normal operation. Second, data can be
shifted into the boundary scan register through JTDI using the Shift-DR state.
EXTEST. EXTEST allows testing of the interconnections to the device. When the EXTEST instruction is latched in
the instruction register, the following actions occur: (1) Once the EXTEST instruction is enabled through the
Update-IR state, the parallel outputs of the digital output pins are driven. (2) The boundary scan register is
connected between JTDI and JTDO. (3) The Capture-DR state samples all digital inputs into the boundary scan
register.
BYPASS. When the BYPASS instruction is latched into the parallel instruction register, JTDI is connected to JTDO
through the 1-bit bypass register. This allows data to pass from JTDI to JTDO without affecting the device’s normal
operation.
IDCODE. When the IDCODE instruction is latched into the parallel instruction register, the device identification
register is selected. The device ID code is loaded into the device identification register on the rising edge of JTCLK,
following entry into the Capture-DR state. Shift-DR can be used to shift the ID code out serially through JTDO.
During Test-Logic-Reset, the ID code is forced into the instruction register’s parallel output.
HIGHZ. All digital outputs are placed into a high-impedance state. The bypass register is connected between JTDI
and JTDO.
CLAMP. All digital output pins output data from the boundary scan parallel output while connecting the bypass
register between JTDI and JTDO. The outputs do not change during the CLAMP instruction.
8.4 JTAG Test Registers
IEEE 1149.1 requires a minimum of two test registers—the bypass register and the boundary scan register. An
optional test register, the identification register, has been included in the device design. It is used with the IDCODE
instruction and the Test-Logic-Reset state of the TAP controller.
Bypass Register. This is a single 1-bit shift register used with the BYPASS, CLAMP, and HIGHZ instructions to
provide a short path between JTDI and JTDO.
Boundary Scan Register. This register contains a shift register path and a latched parallel output for control cells
and digital I/O cells. BSDL files are available at www.maxim-ic.com/TechSupport/telecom/bsdl.htm.
Identification Register. This register contains a 32-bit shift register and a 32-bit latched parallel output. It is
selected during the IDCODE instruction and when the TAP controller is in the Test-Logic-Reset state. The device
identification code for the MAX24287 is shown in Table 8-2.
Table 8-2. JTAG ID Code
DEVICE
MAX24287
REVISION
Note 1
DEVICE CODE
0101 1110 1101 1111
MANUFACTURER CODE
00010100001
REQUIRED
1
Note 1: 0000 = rev A1. 0001 = rev B1. Other values: contact factory.
57
_________________________________________________________________________________________________ MAX24287
9. Electrical Characteristics
ABSOLUTE MAXIMUM RATINGS
Voltage Range on Any Signal IO Lead with Respect to VSS ................................................................ -0.3V to +5.5V
Supply Voltage (VDD12) Range with Respect to VSS ........................................................................ -0.3V to +1.32V
Supply Voltage (VDD33) Range with Respect to VSS ......................................................................... -0.3V to +3.63V
Operating Temperature Range: Industrial ............................................................................................ -40°C to +85°C
Storage Temperature Range ...............................................................................................................-55°C to +125°C
Lead Temperature (soldering, 10s).................................................................................................................... +300°C
Soldering Temperature (reflow) ......................................................................................................................... +260°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only,
and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is
not implied. Exposure to the absolute maximum rating conditions for extended periods may affect device. Ambient operating temperature range
when device is mounted on a four-layer JEDEC test board with no airflow.
Note 1: The typical values listed in the tables of section 9 are not production tested.
Note 2: Specifications to TA = -40°C are guaranteed by design and not production tested.
9.1
Recommended Operating Conditions
Table 9-1. Recommended DC Operating Conditions
PARAMETER
SYMBOL
CONDITIONS
Supply Voltage, Nominal 1.2V
Supply Voltage, Nominal 3.3V
Ambient Temperature Range
Junction Temperature Range
9.2
VDD12
VDD33
TA
TJ
MIN
TYP
MAX
UNITS
1.14
3.135
-40
-40
1.2
3.3
1.26
3.465
+85
+125
V
V
°C
°C
DC Electrical Characteristics
Unless otherwise stated, all specifications in this section are valid for VDD12 = 1.2V ±5%, VDD33 = 3.3V ±5%
and TA = -40°C to +85°C.
Table 9-2. DC Characteristics
PARAMETER
Supply Current, VDD12 Pins
Supply Current, VDD33 Pin
Supply Current, VDD12 Pins
Supply Current, VDD33 Pin
Input Capacitance
Output Capacitance
SYMBOL
IDD12
IDD33
IDD12
IDD33
CIN
COUT
CONDITIONS
10, 25 or 125MHz REFCLK
10, 25 or 125MHz REFCLK
12.8MHz REFCLK (Note 1)
12.8MHz REFCLK
MIN
TYP
135
100
160
140
4
7
MAX
205
175
UNITS
mA
mA
mA
mA
pF
pF
Note 1: When a 12.8MHz oscillator is used the TX PLL uses a two-stage process to perform the frequency conversion and therefore consumes
additional power.
58
_________________________________________________________________________________________________ MAX24287
9.2.1 CMOS/TTL DC Characteristics
Table 9-3. DC Characteristics for Parallel and MDIO Interfaces
PARAMETER
SYMBOL
CONDITIONS
MIN
Output High Voltage
VOH
IOH = -1mA, VDD=3.135V
Output Low Voltage
VOL
Output High Voltage
MAX
UNITS
2.4
5.5
V
IOL = 1mA, VDD=3.135V
0
0.4
V
VOH
MDC, MDIO. Notes 1, 3, 4
2.4
VDD
V
Output Low Voltage
VOL
MDC, MDIO. Notes 2, 3, 4
0
0.4
V
Input High Voltage
VIH
2.0
VDD+0.2V
V
Input Low Voltage
VIL
-0.2
0.8
V
Input High Current
IIH
10
µA
Input Low Current, all other
Input Pins
IIL
Output and I/O Leakage
(when High Impedance)
ILO
Note 1:
Note 2:
Note 3:
Note 4:
TYP
VIN=3.3V
VIN=0V
µA
-10
-10
+10
µA
IOH=-4mA
IOL=4mA
MDC load: 340pF max.
MDIO load: 340pF max plus 2kΩ±5% pulldown resistor.
9.2.2 SGMII/1000BASE-X DC Characteristics
Table 9-4. SGMII/1000BASE-X Transmit DC Characteristics
PARAMETER
Output Voltage High, TDP
or TDN (Single-Ended)
Output Voltage Low, TDP
or TDN (Single-Ended)
Output Common Mode
Voltage
Differential Output Voltage
|VTDP – VTDN|
Differential Output Voltage
|VTDP – VTDN| Peak-to-Peak
Output Common Mode
Voltage
Differential Output Voltage,
|VTDP – VTDN|
Differential Output Voltage,
|VTDP – VTDN| Peak-to-Peak
Output Impedance
Mismatch in a pair
SYMBOL
CONDITIONS
MIN
VOH,DC
VOL,DC
VOCM,DC
VOD,DC
DC-coupled. Load: 50Ω
pullup resistors to
TVDD33 on TDP pin and
on TDN pin. (Note 1)
V
V
320
400
500
mV
640
800
1000
mVP-P
AC-coupled to100Ω load.
See Figure 6-5.
VOD,AC,PP
Single Ended, to TVDD33
UNITS
V
VTVDD33
– 0.4
VTVDD33–
0.2
VOCM,AC
ROUT
∆ROUT
MAX
VTVDD33
VOD,DC,PP
VOD,AC
TYP
VTVDD33–
0.4
V
400
mV
800
mVP-P
35
50
65
10
Ω
%
MIN
TYP
MAX
UNITS
VRVDD33
VRVDD33
V
V
Table 9-5. SGMII/1000BASE-X Receive DC Characteristics
PARAMETER
Input Voltage, RDP pin
Input Voltage, RDN pin
Input Common Mode
Voltage
Input Differential Voltage
SYMBOL
CONDITIONS
VRDP
VRDN
VICM
VID
1.4
1.4
External components as
shown in Figure 6-5.
|VRDP – VRDN|
2.64
200
V
1600
mV
59
_________________________________________________________________________________________________ MAX24287
9.3
AC Electrical Characteristics
Unless otherwise stated, all specifications in this section are valid for VDD12 = 1.2V ±5%, VDD33 = 3.3V ±5%
and TA = -40°C to +85°C.
9.3.1
REFCLK AC Characteristics
Table 9-6. REFCLK AC Characteristics
PARAMETER
Frequency Accuracy
Duty Cycle
Rise Time (20−80%)
Fall Time (20−80%)
SYMBOL
CONDITIONS
∆f/f
MIN
TYP
MAX
UNITS
-100
+100
48
52
1
1
ppm
%
ns
ns
MAX
UNITS
+100
20
Mbps
ppm
ps
tR
tF
REFCLK Jitter: See Table 9-10 below.
9.3.2 SGMII/1000BASE-X Interface Receive AC Characteristics
Table 9-7. 1000BASE-X and SGMII Receive AC Characteristics
PARAMETER
Input Data Rate, Nominal
Input Frequency Accuracy
Skew, RDP vs. RDN
SYMBOL
CONDITIONS
fIN
∆f/f
|tskew|
MIN
TYP
1250
-100
Note 1
Note 1: Measured at 50% of the transition
Table 9-8. 1000BASE-X and SGMII Receive Jitter Tolerance
PARAMETER
Rx Jitter Tolerance, Deterministic Jitter, max
Rx Jitter Tolerance, Total Jitter, max
SYMBOL
CONDITIONS
UI p-p
ps p-p
DJRD
TJRD
Note 1, 2
Note 1, 2
0.46
0.75
370
600
Note 1: Jitter requirements represent high-frequency jitter (above 637kHz) and do not represent low-frequency jitter or wander. Random jitter =
Total Jitter minus Deterministic Jitter.
Note 2: The bandwidth of the CDR PLL is approximately 4MHz.
9.3.3 SGMII/1000BASE-X Interface Transmit AC Characteristics
Table 9-9. SGMII and 1000BASE-X Transmit AC Characteristics
PARAMETER
SYMBOL
CONDITIONS
TCLKP/TCLKN Duty Cycle
at 625MHz
tR
Rise Time (20−80%)
tF
Fall Time (20−80%)
TCLK edge to TD valid data
tclock2q
Note 1
MIN
48
100
100
250
TYP
MAX
52
200
200
550
UNITS
%
ps
ps
ps
UI p-p
0.10
0.24
Max
ps p-p
80
192
Note 1: Measured at 0V differential. Does not include effects of jitter.
Table 9-10. 1000BASE-X Transmit Jitter Characteristics
PARAMETER
Tx Output Jitter, Deterministic
Tx Output Jitter, Total
SYMBOL
CONDITIONS
DJTD
TJTD
Note 1, 2
Note 1, 2
Typical
UI p-p
ps p-p
0.025
20
0.0875
70
Note 1: Jitter requirements represent high-frequency jitter (above 637kHz) and do not represent low-frequency jitter or wander. Random jitter =
Total Jitter minus Deterministic Jitter.
Note 2: Typical values are room-temperature measurements with a Connor-Winfield MX010 crystal oscillator connected to the REFCLK pin.
Note that the bandwidth of the TX PLL is in the 300-400kHz range.
60
_________________________________________________________________________________________________ MAX24287
9.3.4 Parallel Interface Receive AC Characteristics
Figure 9-1. MII/GMII/RGMII/TBI/RTBI Receive Timing Waveforms
tLOW
tPERIOD
Rx Clock5
tHIGH
tDELAY
RXD, RX_DV,
RX_ER, COMMA6
Table 9-11. GMII and TBI Receive AC Characteristics
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
RXCLK Period
tPERIOD
GMII or TBI with one
125MHz Rx clock, Note 5
7.5
8
8.5
ns
RXCLK, RXCLK1 Period
tPERIOD
Normal TBI
15
16
17
ns
40
60
%
1
5.5
ns
5
Rx Clock Duty Cycle
5
Rx Clock Rising Edge to
RXD, RX_DV, RX_ER,
COMMA Valid
tDELAY
Notes 1, 6
RXCLK Rise Time
tR
GMII mode, 0.7V to 1.9V
1
ns
RXCLK Fall Time
tF
GMII mode, 1.9V to 0.7V
1
ns
5
tR
TBI mode, 0.8V to 2.0V
2
ns
5
tF
TBI mode, 2.0V to 0.8V
2
ns
Rx Clock Rise Time
Rx Clock Fall Time
5
0.7V to 1.9V, Note 2
0.6
V/ns
5
1.9V to 0.7V, Note 2
0.6
V/ns
Normal TBI mode
7.5
Normal TBI mode, Note 3
0.2
Rx Clock Slew Rate Rising
Rx Clock Slew Rate Falling
RXCLK vs. RXCLK1 Skew
tRCSKEW
RXCLK, RXCLK1 Drift Rate
tDRIFT
8
8.5
ns
µs/MHz
Note 1: 802.3 specifies setup and hold times for the receiver of the signals. This output delay specification has values that ensure 802.3 setup
and hold specifications are met.
Note 2: Clock Slew rate is the instantaneous rate of change of the clock potential with respect to time (dV/dt), not an average value over the
entire rise or fall time interval. Conformance with this specification guarantees that the clock signals will rise and fall monotonically
through the switching region.
Note 3: tDRIFT is the (minimum) time for RXCLK/RXCLK1 to drift from 63.5MHz to 64.5MHz or 60MHz to 59MHz from the RXCLK lock value. It is
applicable under all input signal conditions (except during the code group alignment process), including invalid or absent input signals,
provided that the receiver clock recovery unit was previously locked to REFCLK or to a valid input signal.
Note 4: All specifications in this table are guaranteed by design with output load of 5pF for GMII mode and 10pF for TBI.
Note 5: The term "Rx Clock" above stands for RXCLK in GMII mode, both RXCLK and RXCLK1 in normal TBI mode, and RXCLK for TBI with
one 125MHz receive clock.
Note 6: COMMA signal only applicable in TBI and RTBI modes.
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Table 9-12. RGMII-1000 and RTBI Receive AC Characteristics
PARAMETER
RXCLK Period
SYMBOL
CONDITIONS
tPERIOD
RXCLK Duty Cycle
MIN
TYP
MAX
UNITS
7.5
8
8.5
ns
tLOW % of tPERIOD , Note 1
45
55
%
-0.2
0.8
ns
RXCLK to RXD, RX_CTL
Delay
tDELAY
Notes 2, 3
Rise Time, All RX Signals
tR
20% to 80%
0.75
ns
Fall Time, All RX Signals
tF
20% to 80%
0.75
ns
Note 1: Per the RGMII spec, duty cycle may be stretched/shrunk during speed changes or while transitioning to a received packet's clock
domain as long as minimum duty cycle is not violated and stretching occurs for no more than three clock cycles of the lowest speed
transitioned between.
Note 2: RXCLK timing is from both edges in RGMII 1000 Mbps mode.
Note 3: the RGMII specification requires clocks to be routed such that a trace delay is added to the RXCLK signal to provide sufficient setup
time for RXD and RX_CTL vs. RXCLK at the receiving component.
Note 4: All specifications in this table are guaranteed by design with output load of 5pF.
Table 9-13. RGMII-10/100 Receive AC Characteristics
10 Mbps
PARAMETER
SYMBOL
MIN
TYP
RXCLK Period
tPERIOD
400
RXCLK Duty Cycle (Note 4)
MAX
MIN
100 Mbps
TYP
40
MAX
UNITS
ns
45
55
45
55
%
-0.2
0.8
-0.2
0.8
ns
RXCLK to RXD, RX_CTL
Delay (Notes 1, 2)
tDELAY
Rise Time, All RX Signals,
20% to 80%
tR
0.75
0.75
ns
Fall Time, All RX Signals,
20% to 80%
tF
0.75
0.75
ns
Note 1: RXCLK to RXD is timed from rising edge.
Note 2: RXCLK to RX_CTL is timed from both RXCLK edges.
Note 3: Per the RGMII spec, duty cycle may be stretched/shrunk during speed changes or while transitioning to a received packet's clock
domain as long as minimum duty cycle is not violated and stretching occurs for no more than three clock cycles of the lowest speed
transitioned between.
Note 4: All specifications in this table are guaranteed by design with output load of 5pF.
Table 9-14. MII–DCE Receive AC Characteristics
PARAMETER
RXCLK Period
SYMBOL
tPERIOD
RXCLK Duty Cycle
RXCLK to RXD, RX_DV,
RX_ER Delay
MIN
tDELAY
10 Mbps
TYP
400
MAX
MIN
100 Mbps
TYP
40
MAX
UNITS
ns
45
55
45
55
%
180
230
18
30
ns
Note 1: RXCLK is an output in this mode.
Note 2: 802.3 specifies setup and hold times, but setup and hold specifications are typically for inputs to an IC rather than outputs. This output
delay specification has values that ensure 802.3 setup and hold specifications are met.
Note 3: All specifications in this table are guaranteed by design with output load of 5pF.
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_________________________________________________________________________________________________ MAX24287
Table 9-15. MII–DTE Receive AC Characteristics
PARAMETER
RXCLK Period
SYMBOL
MIN
tPERIOD
RXCLK Duty Cycle
RXCLK to RXD, RX_DV,
RX_ER Delay
tDELAY
10 Mbps
TYP
400
MAX
MIN
100 Mbps
TYP
40
MAX
UNITS
ns
45
55
45
55
%
0
10
0
10
ns
Note 1: RXCLK is an input in this mode.
Note 2: 802.3 specifies setup and hold times, but setup and hold specifications are typically for inputs to an IC rather than outputs. This output
delay specification has values that ensure 802.3 setup and hold specifications are met.
Note 3: All specifications in this table are guaranteed by design with output load of 5pF.
9.3.5 Parallel Interface Transmit AC Characteristics
Figure 9-2. MII/GMII/RGMII/TBI/RTBI Transmit Timing Waveforms
tPERIOD
TX_CLK
GTX_CLK
tHIGH
tLOW
tSETUP
TXD[7:0]
TX_EN,
TX_ER
tHOLD
Table 9-16. GMII, TBI, RGMII-1000 and RTBI Transmit AC Characteristics
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
0.9
V
Input Voltage Low, AC
VIL_AC
Input Voltage High, AC
VIH_AC
1.7
GTXCLK Period
tPERIOD
7.2
GTXCLK Low Time
tLOW
2.5
ns
GTXCLK High Time
tHIGH
2.5
ns
GMII mode or TBI mode,
tLOW % of tPERIOD
GTXCLK Duty Cycle
RGMII-1000 mode,
GTXCLK Duty Cycle
tLOW % of tPERIOD
V
8
8.8
ns
40
60
%
45
55
%
GTXCLK, TXD, TX_DV,
TX_ER Rise Time
tR
30% to 70% of VDD33,
Note 1
0.5
2
ns
GTXCLK, TXD, TX_DV,
TX_ER Fall Time
tF
70% to 30% of VDD33,
Note 1
0.5
2
ns
TXD, TX_DV, TX_ER to
GTXCLK Setup Time
tSETUP
Note 1
1
ns
GTXCLK to TXD, TX_DV,
TX_ER Hold Time
tHOLD
Note 1
0
ns
Note 1: GTXCLK timing is from both edges in RGMII 1000 Mbps mode.
Note 2: All specifications in this table are guaranteed by design.
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Table 9-17. RGMII-10/100 Transmit AC Characteristics
10 Mbps
PARAMETER
SYMBOL
MIN
TYP
GTXCLK Period
tPERIOD
400
GTXCLK Duty Cycle
(Note 3)
40
MAX
60
MIN
100 Mbps
TYP
40
40
MAX
UNITS
ns
60
%
TXD, TX_CTL to GTXCLK
Setup Time
tSETUP
1
1
ns
GTXCLK to TXD, TX_CTL
Hold Time
tHOLD
0
0
ns
Rise Time, All TX Signals,
0.5V to 2.0V
tR
0.75
0.75
ns
Fall Time, All TX Signals,
0.5V to 2.0V
tF
0.75
0.75
ns
Note 1: TXCLK to TXD is timed from rising edge.
Note 2: TXCLK to TX_CTL is timed from both TXCLK edges.
Note 3: Per the RGMII spec, duty cycle may be stretched/shrunk during speed changes or while transitioning to a received packet's clock
domain as long as minimum duty cycle is not violated and stretching occurs for no more than three clock cycles of the lowest speed
transitioned between.
Note 4: All specifications in this table are guaranteed by design.
Table 9-18. MII–DCE Transmit AC Characteristics
PARAMETER
TXCLK Period
SYMBOL
MIN
tPERIOD
TXCLK Duty Cycle
45
10 Mbps
TYP
MAX
400
55
MIN
100 Mbps
TYP
40
45
UNITS
MAX
ns
55
%
TXD, TX_DV, TX_ER to
TXCLK Setup Time
tSETUP
6.5
6.5
ns
TXCLK to TXD, TX_DV,
TX_ER Hold Time
tHOLD
0
0
ns
Note 1: TXCLK is an output in this mode.
Note 2: All specifications in this table are guaranteed by design.
Table 9-19. MII–DTE Transmit AC Characteristics
PARAMETER
TXCLK Period
SYMBOL
MIN
tPERIOD
TXCLK Duty Cycle
40
10 Mbps
TYP
MAX
400
60
MIN
40
100 Mbps
TYP
40
MAX
UNITS
ns
60
%
TXD, TX_DV, TX_ER to
TXCLK Setup Time
tSETUP
6.5
6.5
ns
TXCLK to TXD, TX_DV,
TX_ER Hold Time
tHOLD
0
0
ns
Note 1: TXCLK is an input in this mode.
Note 2: All specifications in this table are guaranteed by design.
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9.3.6 MDIO Interface AC Characteristics
Table 9-20. MDIO Interface AC Characteristics
Parameter
MDC Input Period (12.5MHz)
MDC Input High
MDC Input Low
MDIO Input Setup Time to MDC
MDIO Input Hold Time from MDC
MDC to MDIO Output Delay
MDC to MDIO High Impedance
Symbol
t1
t2
t3
t4
t5
t6
t6
Conditions
Note 1
Notes 1, 2
Notes 1, 2
Note 1
Note 1
Note 1,3
Note 1,4
Min
80
30
30
10
10
0
0
Typ
Max
40
40
Units
ns
ns
ns
ns
ns
ns
ns
Note 1: The input/output timing reference level for all signals is VDD33/2. All parameters are with 340pF load on MDC and 340pF load and 2kΩ
pulldown on MDIO.
Note 2: All specifications in this table are guaranteed by design.
Note 3: Data is valid on MDIO until min delay time.
Note 4: When going to high impedance, data is valid until min and signal is high impedance after max.
Figure 9-3. MDIO Interface Timing
t1
t2
t3
MDC
t4
t5
MDIO
(input)
t6
MDIO
(output)
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9.3.7 JTAG Interface AC Characteristics
Table 9-21. JTAG Interface Timing
PARAMETER
JTCLK Clock Period
SYMBOL
t1
MIN
TYP
1000
JTCLK Clock High/Low Time (Note 1)
t2/t3
50
500
JTCLK to JTDI, JTMS Setup Time
t4
50
ns
JTCLK to JTDI, JTMS Hold Time
t5
50
ns
JTCLK to JTDO Delay
t6
2
JTCLK to JTDO High-Impedance Delay (Note 2)
t7
JTRST_N Width Low Time
t8
100
MAX
UNITS
ns
ns
50
ns
50
ns
ns
Note 1: Clock can be stopped high or low.
Note 2: All specifications in this table are guaranteed by design.
Figure 9-4. JTAG Timing Diagram
t1
t2
t3
JTCLK
t4
t5
JTDI, JTMS
t6
t7
JTDO
JTRST_N
t8
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Pin Assignments
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
REFCLK
RST_N
GTXCLK
DVDD33
N.C.
N.C.
N.C.
GPIO1
GPIO2
GPIO3
TX_ER
TX_EN
DVDD12
TXD[7]/GPIO7
TXD[6]/GPIO6
TXD[5]/GPIO5
TXD[4]/GPIO4
10.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
MAX24287
EP
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
TXD[3]
TXD[2]
TXD[1]
TXD[0]
DVSS
TXCLK/RCLK1
N.C.
JTDO
JTRST_N
MDIO
MDC
RXCLK
DVDD33
RXD[0]
RXD[1]
RXD[2]
RXD[3]
GVDD12
ALOS
DVDD33
JTCLK
JTMS
JTDI
GPO1
GPO2
CRS/COMMA
COL
RX_ER
RX_DV
DVDD12
RXD[7]
RXD[6]
RXD[5]
RXD[4]
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
GVSS
CVDD33
CVDD12
CVSS
TCLKN
TCLKP
TVDD33
TDN
TDP
TVSS
TVDD12
RVDD33
RDP
RDN
RVSS
RVDD12
N.C.
N.C. = Not connected internally.
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11.
Package and Thermal Information
For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages.
Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different
suffix character, but the drawing pertains to the package regardless of RoHS status.
PACKAGE TYPE
PACKAGE CODE
OUTLINE NO.
LAND PATTERN NO.
68 TQFN-EP
(8mm x 8mm)
T6888+1
21-0510
90-0354
Note: The exposed pad (EP) on the bottom of this package must be connected to the ground plane. EP also
functions as a heatsink. Solder to the circuit-board ground plane to achieve the thermal specifications listed below.
For more information about exposed pads, consult Maxim's Application Note 3273.
Table 11-1. Package Thermal Properties, Natural Convection
CONDITIONS
PARAMETER
Note 1
Ambient Temperature
Junction Temperature
Note 2
Theta-JA (θJA)
MIN
-40°C
-40°C
TYP
MAX
+85°C
+125°C
20.2°C/W
Note 1: The package is mounted on a four-layer JEDEC standard test board with no airflow and dissipating maximum power.
Note 2: Theta-JA (θJA) is the junction to ambient thermal resistance, when the package is mounted on a four-layer JEDEC standard test board
with no airflow and dissipating maximum power.
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12.
Data Sheet Revision History
REVISION
NUMBER
REVISION
DATE
0
7/11
DESCRIPTION
Initial release
PAGES
CHANGED
—
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
 2011 Maxim Integrated Products
69
Maxim is a registered trademark of Maxim Integrated Products.