Texas Instruments TNETX3270 - page 31

TNETX3270

ThunderSWITCH 24/3 ETHERNET SWITCH

WITH 24 10-MBIT/S PORTS AND 3 10-/100-MBIT/S PORTS

SPWS043B – NOVEMBER 1997 – REVISED APRIL 1999

31

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

Table 11. 10-Mbit/s Interface Connections

TNETX3270

TERMINAL TNETE2008

TERMINAL

THxCLK ←IFCLK

THxSYNC ←IFSYNC

THxCOL ←IFCOL

THxCRS ←IFCRS

THxLINK ←IFLINK

THxRXD3 ←IFRXD3

THxRXD2 ←IFRXD2

THxRXD1 ←IFRXD1

THxRXD0 ←IFRXD0

THxRXDV ←IFRXDV

THxTXD3 →IFTXD3

THxTXD2 →IFTXD2

THxTXD1 →IFTXD1

THxTXD0 →IFTXD0

THxTXEN →IFTXEN

THxRENEG →IFFORCEHD

Where x = 0, 1, or 2

The time multiplexing of this interface is shown in Figure 6. The interface runs synchronous to the

PHY-generated 20-MHz clock IFCLK. The MAC-to-PHY information for the first port in each group of eight (i.e.,

port 00, port 08, or port 16) is presented on the interface when the THxSYNC terminal is high. The next clock

cycle that the interface carries is the information for the second port. This process continues for all eight ports,

each using the interface for one cycle. When all ports have been processed in this manner, the sequence

resumes with the first port and again when the THxSYNC signal is asserted.

To improve latency-related issues, the PHY -to-MAC data are skewed by two slots, allowing the MAC to respond

to the input signals from the PHY in the same 400-ns cycle, rather than waiting for the next 400-ns cycle (which

would be the case if the signals were not skewed).

Contents

Main TNETX3270 ThunderSWITCH24/3 ETHERNET SWITCH WITH 24 10-MBIT/S PORTS AND 3 10-/100-MBIT/S PORTS TNETX3270 ThunderSWITCH24/3 ETHERNET SWITCH WITH 24 10-MBIT/S PORTS AND 3 10-/100-MBIT/S PORTS description TNETX3270 ThunderSWITCH24/3 ETHERNET SWITCH WITH 24 10-MBIT/S PORTS AND 3 10-/100-MBIT/S PORTS ThunderSWITCH24/3 ETHERNET SWITCH WITH 24 10-MBIT/S PORTS AND 3 10-/100-MBIT/S PORTS SPWS043B NOVEMBER 1997 REVISED APRIL 1999 PGV PACKAGE (TOP VIEW) ThunderSWITCH 24/3 ETHERNET SWITCH PRODUCT PREVIEW Figure 1. TNETX3270 Interface Block Diagram Page TNETX3270 10-/100-Mbit/s MAC interface (ports 2426) 10-/100-Mbit/s MAC interface (ports 2426) (continued) SDRAM interface WITH 24 10-MBIT/S PORTS AND 3 10-/100-MBIT/S PORTS host DIO interface serial MII management PHY interface EEPROM interface LED interface JTAG interface miscellaneous power interface summary of signal terminals by signal group function DIO register groups Table 1. Internal Register and Statistics Memory Map Table 2. Detailed DIO Register Map Page Page Page interface description receiving/transmitting management frames state of DIO signals during hardware reset network management port Page Page receive control giant (long) frames short frames receive filtering of frames data transmission transmit control adaptive performance optimization (APO) (transmit pacing) interframe gap enforcement ThunderSWITCH 24/3 ETHERNET SWITCH WITH 24 10-MBIT/S PORTS AND 3 10-/100-MBIT/S PORTS receive versus transmit priority uplink pretagging Table 5. Source-Port Pretag Encoding Page TNETX3270 interaction of EEPROM load with the SIO register summary of EEPROM load outcomes compatibility with future device revisions HIGHZ instruction lamp test multi-LED display hardware configurations Page TNETX3270 Figure 6. 10-Mbit/s Interface-Port Signal Timing Figure 7. Connecting to TNETE2008 PHY 10-/100-Mbit/s port configuration 10-/100-Mbit/s port configuration (continued) 10-/100-Mbit/s port configuration in a nonmanaged switch 10-/100-Mbit/s port configuration in a managed switch SDRAM interface (continued) Table 15. TNETX3270 Terminal Interface to SDRAMs SDRAM-type and quantity indication initialization refresh 39 frame routing txacc Figure 8. VLAN Overview Transmit rxacc IEEE Std 802.1Q headers reception IEEE Std 802.1Q headers transmission address maintenance spanning-tree support aging algorithms frame-routing determination Unkmem Figure 9. Frame-Routing Algorithm interrupt UnkVLAN Figure 9. Frame-Routing Algorithm (Continued) new chng secvio Port Trunking/Load Sharing port mirroring port trunking/load sharing collision-based flow control IEEE Std 802.3 flow control Page internal wrap test duplex wrap test Page absolute maximum ratings over operating junction temperature range (unless otherwise noted) recommended operating conditions electrical characteristics over recommended operating conditions (unless otherwise noted) PARAMETER MEASUREMENT INFORMATION test measurement 10-Mbit/s interface (ports 0023) timing requirements (see Notes 3 through 6 and Figure 13) Figure 13. 10-Mbit/s Interface (Ports 0023) 10-/100-Mbit/s MAC interface Figure 14. 10-/100-Mbit/s Receive Ports 10-/100-Mbit/s timing requirements (see Note 7 and Figure 14) 10-/100-Mbit/s timing requirements (see Figure 15) operating characteristics over recommended operating conditions (see Note 8 and Figure 15) Figure 15. 10-/100-Mbit/s Transmit Ports SDRAM interface SDRAM subcycle operating characteristics over recommended operating conditions (see Figure 17) Figure 17. SDRAM Subcycle DIO/DMA interface Figure 18. DIO/DMA Write Cycle timing requirements (see Figure 18) operating characteristics over recommended operating conditions (see Figure 18) DIO/DMA read cycle timing requirements (see Figure 19) Figure 19. DIO/DMA Read Cycle operating characteristics over recommended operating conditions (see Figure 19) serial MII management interface timing requirements (see Figure 20) operating characteristics over recommended operating conditions (see Figure 20) Figure 20. Serial MII Management Read/Write Cycle EEPROM interface operating characteristics over recommended operating conditions (see Figure 21) Figure 21. EEPROM LED interface operating characteristics over recommended operating conditions (see Figure 22) Figure 22. LED power-up OSCIN and RESET timing requirements (see Figure 23) Figure 23. Power-Up OSCIN and RESET MECHANICAL DATA PGV (S-PQFP-G240) PLASTIC QUAD FLATPACK (DIEDOWN)