LXT983QC Intel Corporation, LXT983QC Datasheet
LXT983QC
Available stocks
Related parts for LXT983QC
LXT983QC Summary of contents
Page 1
LXT983/983A LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater General Description The LXT983 is a 5-port 10/100 Class II Repeater that is fully compliant with IEEE 802.3 standards. Four ports directly support 100BASE-TX/10BASE-T copper media and also support 100BASE-FX fiber media ...
Page 2
... Copies of documents which have an ordering number and are referenced in this document, or other Intel literature may be obtained by calling 1-800- 548-4725 or by visiting Intel’s website at http://www.intel.com. Copyright © Intel Corporation, 2001 *Third-party brands and names are the property of their respective owners. ...
Page 3
Contents 1.0 Pin Assignments and Signal Descriptions 2.0 Functional Description 2.1 Introduction..........................................................................................................16 2.1.1 TP/FX Port Configuration .......................................................................16 2.1.2 MII Port Configuration ............................................................................17 2.1.3 Interface Descriptions.............................................................................18 2.1.4 Repeater Operation................................................................................21 2.2 Requirements ......................................................................................................22 2.2.1 Power .....................................................................................................22 2.2.2 Clock ......................................................................................................23 2.2.3 Bias Current ...
Page 4
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Figures 1 LXT983/983A Block Diagram................................................................................ 7 2 LXT983 Pin Assignments ..................................................................................... 8 3 Typical Managed Repeater Architectures .......................................................... 17 4 Typical Hybrid Switch/Repeater Application ...................................................... 18 5 Typical Application Block Diagram ..................................................................... 19 ...
Page 5
Tables 1 Mode Control Signal Descriptions ......................................................................... 9 2 Twisted-Pair Port Signal Descriptions ................................................................... 9 3 Fiber Port Signal Descriptions............................................................................... 9 4 PHY Mode MII Signal Descriptions .....................................................................10 5 MAC Mode MII Signal Descriptions.....................................................................10 6 Inter-Repeater Backplane Signal Descriptions....................................................11 7 ...
Page 6
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Revision History Revision Date 6 Description Datasheet ...
Page 7
Figure 1. LXT983/983A Block Diagram 10 Mbps 10M IRB Backplane 100 Mbps 100M IRB Backplane Control Port & Segment LED Drivers Status Indicators Datasheet LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater LXT983 10BASE-T Repeater 100BASE-T Repeater Control Logic & Clocking ...
Page 8
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater 1.0 Pin Assignments and Signal Descriptions Figure 2. LXT983 Pin Assignments RESET ...... 53 CLK25 ...... 54 N/C ...... 55 N/C ...... 56 VCC ...... 57 N/C ...... 58 N/C ...... 59 N/C ...
Page 9
Table 1. Mode Control Signal Descriptions 1 Pin Symbol Type 189 PORT1_SPD0 188 PORT1_SPD1 187 PORT2_SPD0 TTL Input, 186 PORT2_SPD1 Latched on reset, 185 PORT3_SPD0 184 PORT3_SPD1 PU 183 PORT4_SPD0 182 PORT4_SPD1 TTL Input, 100 PORT5_SPD PU 99 PORT5_SEL Input ...
Page 10
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Table 4. PHY Mode MII Signal Descriptions 1 Pin Symbol Type 29 MII_RXD0 30 MII_RXD1 Output 32 MII_RXD2 TTL 33 MII_RXD3 Output 26 MII_RXDV TTL Output 25 MII_RXCLK TTL Output 24 MII_RXER TTL ...
Page 11
Table 5. MAC Mode MII Signal Descriptions (Continued) 1 Pin Symbol Type Output 20 MII_TXEN TTL 19 MII_TXD0 18 MII_TXD1 Output TTL 17 MII_TXD2 16 MII_TXD3 Input 14 MII_COL TTL Input 13 MII_CRS TTL 1. MII interface pins reverse direction ...
Page 12
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Table 6. Inter-Repeater Backplane Signal Descriptions (Continued) Pin Symbol Type Analog I/O 37 IR100CFSBP NC Schmitt 38 IR100SNGL CMOS I/O, PU Schmitt MOS 40 IR100COL I/O, PU CMOS I/O 9 IR10DAT OD, PD ...
Page 13
Table 6. Inter-Repeater Backplane Signal Descriptions (Continued) Pin Symbol Type Analog I/O 5 IR10CFSBP OD, NC TTL Input 79 MACACTIVE PD TTL I/O 80 HOLDCOL Clamp. Pad will not clamp input in the absence of ...
Page 14
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Table 7. LED Signal Descriptions (Continued) Pin Symbol Type TTL 86 COL100_LED Output TTL 90 ACT10_LED Output TTL 91 ACT100_LED Output Input contains pull-down. TTL = Transistor-Transistor Logic. Table 8. ...
Page 15
Table 9. Miscellaneous Signal Descriptions Pin Symbol Type Schmitt, CMOS 53 RESET Input, Schmitt CMOS 54 CLK25 71 FPS TTL Input TTL Input, AUTO_BLINK 74 (LXT983A) 7, 15, 23, 31, 39, 47, 48, 55, 56, 58-70, 77, 78, 81, 87, ...
Page 16
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater 2.0 Functional Description 2.1 Introduction As a fully integrated IEEE 802.3 repeater capable of 10 Mbps and 100 Mbps functionality, the LXT983 is a very versatile device allowing great flexibility in Ethernet design ...
Page 17
Auto-Negotiation Any port can be configured to establish its link via auto-negotiation. The port and its link partner establish link conditions by exchanging Fast Link Pulse (FLP) bursts. When auto-negotiation is enabled, the capabilities advertised by the LXT983 are ...
Page 18
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Figure 4. Typical Hybrid Switch/Repeater Application 10M Backplane 100M Backplane MII Switch Connections 1 each for 10 M and 100M 2.1.3 Interface Descriptions The LXT983 provides four network interface ports. Each port provides ...
Page 19
Figure 5. Typical Application Block Diagram MII_RXCLK MII MII_RXD<3:0> MII_RXDV (Port 5, MII_RXER PHY Mode) MII_COL MII_CRS MII_TXCLK MII_TXD<3:0> MII_TXEN MII_TXER Input allows MAC to drive IRB MACACTIVE (10M Only) First Position FPS Select 2 Independent IRBs, 10 & ...
Page 20
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater The receiver requires magnetics with a 1:1 turns ratio, and a load of 100 . When the twisted-pair port is enabled, the receiver actively biases its inputs to approximately 2.8 V. When the ...
Page 21
When the MII is operating as the MAC side of the interface (MAC mode), it always operates at 100 Mbps. When the MII is operating as the PHY side of the interface (PHY mode), it can be programmed to operate ...
Page 22
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater • Un-isolate. The LXT983 will un-isolate a port that remains in the IDLE state for 33000 +/- 25 that receives a valid frame at least 450-500BT in length. • Jabber. The ...
Page 23
Clock A stable, external 25 MHz system clock source (CMOS) is required by the LXT983. This is connected to the CLK25 pin. Refer to Test Specifications, requirements. 2.2.3 Bias Current The LXT983 requires a 22 resistor ...
Page 24
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater 2.3.2 Port LEDs Port LEDs provide status for the four twisted-pair ports and the MII port. The LXT983 has 3 LED driver pins for each port as described in selectable modes are provided ...
Page 25
Table 12. LED Mode 2 Indications Operating LED Mode PORTnLED1 Any PORTnLED2 Any (LXT983) PORTnLED2 10 or 100 Mbps ops (LXT983A) Auto-neg enabled PORTnLED3 Auto-neg disabled 1. Setting AUTO_BLINK (Pin 74) High disables blink (LXT983A only). Table 13. LED Mode ...
Page 26
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater 2.4.1 MAC IRB Access The MACACTIVE pin allows an external MAC or other digital ASIC to interface directly to the 10 Mbps IRB. When the MACACTIVE pin is asserted, the LXT983 will drive ...
Page 27
Table 14. IRB Signal Types Connections Between Devices Connection Type Full Connect all Local Connect all For devices with FPS High, pull-up at each device Stack and do not interconnect. Table 15. IRB Signal Details Name Pad Type IR100DAT<4:0> Digital ...
Page 28
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater The LXT983 can emulate either the PHY (PHY Mode) or MAC (MAC Mode) side of the MII as shown in Figure 7. Mode and speed control is provided via PORT5_SPD and PORT5_SEL pins ...
Page 29
Figure 7. MII (Port 5) Operation The LXT983 MII port is reversible. When PHY mode is selected, the LXT983 acts as the PHY side of the MII. In this mode an external MAC sends TX Data to the LXT983 to ...
Page 30
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Figure 8. MII Timing Issues Propagation Delay Requirements per IEEE 802.3u:- PHY prop delay (MII-TP) must be A Class II RPTR Prop Delay PHY Prop Delay 20 BT MII MAC ...
Page 31
Application Information 3.1 Design Recommendations The LXT983 has been designed to comply with IEEE requirements and to provide outstanding receive BER and long-line-length performance. Lab testing has shown that the LXT983 can perform well beyond the required distance of ...
Page 32
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater The recommended implementation is to divide the VCC plane into two sections. The digital section supplies power to the digital VCC pin and to the external components. The analog section supplies power to ...
Page 33
The RBIAS Pin The LXT983 requires a 22.1 k ground. Place the RBIAS resistor as close to the RBIAS pin as possible. Run an etch directly from the pin to the resistor, and sink the other side of the ...
Page 34
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater 3.1.8 Magnetics Information The LXT980 requires a 1:1 ratio for the receive transformers and a 2:1 ratio for the transmit transformers. The transformer isolation voltage should be rated protect ...
Page 35
Figure 10. Hybrid Switch/Repeater Application - for Balanced 10/100 Performance Memory 10/100 MAC 100 Mbps LXT983 10M 100M MII IRB IRB TP/Fiber Ports Figure 11. Hybrid Switch/Repeater Application - Weighted Toward 100M Performance 100 Mbps MAC 100 Mbps LXT983 100M ...
Page 36
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Figure 12. Power and Ground Connections LXT983 36 To Output Magnetics Center tap VCCT .1 F .01 F GNDT VCCV .1 F .01 F GNDV 22 RBIAS GNDA VCCR .1 F ...
Page 37
Figure 13. Typical Fiber Port Interface FIBONn FIBOPn LXT983 SIGDETn FIBINn FIBIPn Datasheet LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater VCCT + GNDA 0.01 F 0.01 F 191 W 191 W GNDA 2 0.1 ...
Page 38
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Figure 14. Typical Twisted-Pair Port Interface LXT983 1. Receiver common mode bypass cap may improve BER performance in systems with noisy power supplies single ferrite bead may be used to supply ...
Page 39
Figure 15. Typical 100 Mbps IRB Implementation +5V Stack or Segment 1 k Connector ’245 IR100CLKBP A IR100DATBP IR100DVBP\ DIR 91 ENA 1%* 1 IR100CFSBP stacked configurations, all devices with ChipID = 0 are tied together at IR100CFSBP. ...
Page 40
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater 4.0 Test Specifications Table 18 through Figure 40 specifications of the LXT983/983A. These specifications are guaranteed by test except where noted “by design.” Minimum and maximum values listed in the recommended operating conditions ...
Page 41
Table 21. I/O Electrical Characteristics Parameter Sym Input Low voltage V Input High voltage V IH Hysteresis voltage – Output Low voltage V OL Output Low voltage (LED) V OLL Output High voltage V OH Input Low current I IL ...
Page 42
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Table 23. 10 Mbps IRB Electrical Characteristics Parameter Symbol Output Low voltage V OL Output rise or fall time T RF Input High voltage V IH Input Low voltage V IL Hysteresis voltage ...
Page 43
Table 25. 100BASE-FX Transceiver Electrical Characteristics Parameter Symbol Peak differential output voltage (single ended) Signal rise/fall time Jitter (measured differentially) Peak differential input voltage Common mode input range V 1. Typical values are at 25 °C and are for design ...
Page 44
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Figure 18. 100 Mbps Port-to-Port Delay Timing Normal Propagation TP / FIB Input TP / FIB Output Collision Jamming TP / FIB Input # FIB Input # FIB Output ...
Page 45
Figure 19. 100BASE-TX Transmit Timing - PHY Mode MII TX_CLK t 2A TXD, TX_EN, TX_ER t 2C CRS TPOP/N Table 28. 100BASE-TX Transmit Timing Parameters - PHY Mode MII Parameter TXD, TX_EN, TX_ER Setup to TX_CLK High TXD, TX_EN, TX_ER ...
Page 46
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Figure 20. 100BASE-TX Receive Timing - PHY Mode MII TPIP CRS RXD, RX_DV, RX_ER RX_CLK t COL 3F Table 29. 100BASE-TX Receive Timing Parameters - PHY Mode MII Parameter TPIP/N in ...
Page 47
Figure 21. 100BASE-TX Transmit Timing - MAC Mode MII RX_CLK t 4A RXD, RX_DV, RX_ER TPOP/N Table 30. 100BASE-TX Transmit Timing Parameters - MAC Mode MII Parameter RXD, RX_DV, RX_ER Setup to RX_CLK High RXD, RX_DV, RX_ER Hold from RX_CLK ...
Page 48
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Figure 23. 100BASE-FX Transmit Timing - PHY Mode MII TX_CLK t 6A TXD, TX_EN, TX_ER t 6B CRS FIBOP/N Table 32. 100BASE-FX Transmit Timing Parameters - PHY Mode MII Parameter TXD, TX_EN, TX_ER ...
Page 49
Figure 24. 100BASE-FX Receive Timing - PHY Mode MII FIBIP CRS RXD, RX_DV, RX_ER RX_CLK t COL 7F Table 33. 100BASE-FX Receive Timing - PHY Mode MII Parameter FIBIP CRS asserted FIBIP/N quiet to CRS de-asserted ...
Page 50
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Figure 25. 100BASE-FX Transmit Timing - MAC Mode MII RX_CLK t 8A RXD, RX_DV, RX_ER FIBOP/N Table 34. 100BASE-FX Transmit Timing - MAC Mode MII Parameter RXD, RX_DV, RX_ER Setup to RX_CLK High ...
Page 51
Figure 27. 10BASE-T Transmit Timing - PHY Mode MII TX_CLK t 10A TXD, TX_EN, TX_ER t 10C CRS Table 36. 10BASE-T Transmit Timing Parameters - PHY Mode MII Parameter Note: TXD, TX_EN, TX_ER Setup to TX_CLK High Note: TXD, TX_EN, ...
Page 52
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Figure 28. 10BASE-T Receive Timing - PHY Mode MII TPIP/N t 11A CRS RXD, RX_DV, RX_ER RX_CLK t 11D COL Table 37. 10BASE-T Receive Timing Parameters - PHY Mode MII Parameter TPIP/N in ...
Page 53
Figure 29. 100 Mbps IRB Timing TPIP/N FIBIP/N t 12A IR100DV IR100CFS 1R100COL IR100DAT<4:0> IR100CLK Table 38. 100 Mbps IRB Timing Parameters Parameter TPIP/N or FIBP/N to IR100DV Low IR100DAT to IR100CLK setup time. IR100DAT to IR100CLK hold time. 1. ...
Page 54
LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater Figure 30. 10 Mbps IRB Receive Timing TPIP/N t 13A IR10ENA IR10DAT IR10CLK Table 39. 10 Mbps IRB Receive Timing Parameters Parameter TPIP/N to IR10ENA Low IR10CLK rising edge to IR10DAT 3 rising ...
Page 55
Figure 31. 10 Mbps IRB Transmit Timing MACACTIVE t 14A IR10ENA IR10DAT IR10CLK TPOP/N Table 40. 10 Mbps IRB Transmit Timing Parameters Parameter Symbol MACACTIVE to IR10ENA t 14A 3 assertion delay IR10DAT (input) to IR10CLK t 14B setup time ...
Page 56
... LXT983/983A Dual Speed, 5-Port Fast Ethernet Repeater 5.0 Mechanical Specifications Figure 32. LXT983 Package Specifications 208-Pin Plastic Quad Flat Package • Part Number • LXT983QC • LXT983AHC • Commercial Temperature Range ( Millimeters ...