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
53
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
10-Mbit/s interface (ports 00–23)timing requirements (see Notes 3 through 6 and Figure 13)
NO. MIN MAX UNIT
1 tc(THxCLK)Cycle time, THxCLK 50 58 ns
2 Tw(THxCLK) Pulse duration, THxCLK high or low 23 27 ns
3 tsu(THxSYNC) Setup time, THxSYNC high before THxCLK8 ns
4 tsu(THxCOL) Setup time, THxCOL high before THxCLK8 ns
4 tsu(THxCRS) Setup time, THxCRS high before THxCLK8 ns
4 tsu(THxLINK) Setup time, THxLINK high before THxCLK8 ns
4 tsu(THxRXD) Setup time, THxRXD3–THxRXD0 valid before THxCLK8 ns
4 tsu(THxRXDV) Setup time, THxRXDV high before THxCLK8 ns
5 th(THxSYNC) Hold time, THxSYNC high after THxCLK8 ns
6 th(THxCOL) Hold time, THxCOL high after THxCLK8 ns
6 th(THxCRS) Hold time, THxCRS high after THxCLK8 ns
6 th(THxLINK) Hold time, THxLINK high after THxCLK8 ns
6 th(THxRXD) Hold time, THxRXD3–THxRXD0 valid after THxCLK8 ns
6 th(THxRXV) Hold time, THxRXDV high after THxCLK8 ns
tr(THxCLK) Rise time, THxCLK 2 ns
tf(THxCLK) Fall time, THxCLK 2 ns
THx = TH0, TH1, and TH2
NOTES: 3. The TNETE2008 must supply at least two THxSYNC pulses under normal conditions before driving valid data on the inputs to the
TNETX3270, or before expecting valid data on the outputs from the TNETX3270. This means that at least two full sequences must
be executed; only with the third THxSYNC pulse is valid data presented/expected.
4. At least two clocks must be driven before the deassertion of the system reset signal, and a minimum of two clocks must be driven
after the deassertion of the the system reset signal to ensure complete initialization of the internal circuitry of the TNETX3270 before
there is any valid activity across the interface.
5. For receive data, the TNETE2008 asserts the THxCOL signal during the appropriate slot time if it was asserted for any of the four
bits of data corresponding to that slot time.
6. For receive data, the TNETE2008 asserts the THxRXDV signal only if there are four valid bits of data in the nibble.
operating characteristics over recommended operating conditions (see Notes 3 through 6 andFigure 13)
NO. PARAMETER MIN MAX UNIT
7 td(THxEN)Delay time, from THxCLKto THxTXEN13.5 ns
7 td(THxTXD) Delay time, from THxCLKto THxTXD3–THxTXD0 valid 13.5 ns
7 td(THxRENEG) Delay time, from THxCLKto THxRENEG13.5 ns
8 td(THxTXEN) Delay time, from THxCLK to THxTXEN0 ns
8 td(THxTXD) Delay time, from THxCLK to THxTXD3–THxTXD0 invalid 0 ns
8 td(THxRENEG) Delay time, from THxCLK to THxRENEG0 ns
THx = TH0, TH1, and TH2
NOTES: 3. The TNETE2008 must supply at least two THxSYNC pulses under normal conditions before driving valid data on the inputs to the
TNETX3270, or before expecting valid data on the outputs from the TNETX3270. This means that at least two full sequences must
be executed; only with the third THxSYNC pulse is valid data presented/expected.
4. At least two clocks must be driven before the deassertion of the system reset signal, and a minimum of two clocks must be driven
after the deassertion of the the system reset signal to ensure complete initialization of the internal circuitry of the TNETX3270 before
there is any valid activity across the interface.
5. For receive data, TNETE2008 asserts the THxCOL signal during the appropriate slot time if it was asserted for any of the four bits
of data corresponding to that slot time.
6. For receive data, the TNETE2008 asserts the THxRXDV signal only if there are four valid bits of data in the nibble.