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
63
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
power-up OSCIN and RESETtiming requirements (see Figure 23)
NO. MIN NOM MAX UNIT
Frequency drift, OSCIN clock ±50 ppm
1 tc(OSCIN) Cycle time, OSCIN 12 ns
2 tw(OSCINL) Pulse duration, OSCIN low 4.8 7.2 ns
3 tw(OSCINH) Pulse duration, OSCIN high 4.8 7.2 ns
4 tw(RESET) Pulse duration, RESET low 200 µs
5 tsu(RESET) Setup time, RESET low before OSCIN7 ns
6 th(RESET) Hold time, RESET low after OSCIN3 ns
7 td(OSCIN) Delay time, from OSCIN invalid to OSCIN valid (stable) 25 ms
8 td(RESET) Delay time, from OSCIN stable to RESET25 ms
9 tt(OSCIN) Transition time, OSCIN rise and fall 2 ns

RESET must be held low at least 25 ms after both power supplies are stable and OSCIN has reached its stable

operating frequency. RESET can be set to 0 for a minimum of 200 µs to reset the device.

OSCIN
(input)
RESET
(input)
VDD(2.5V)
(input)
VDD(3.3V)
(input)
75
99 1
6
48
32

Figure 23. Power-Up OSCIN and RESET