Texas Instruments THUNDERSWITCH II TNETX4090 - Manual (Page 72)

TNETX4090
ThunderSWITCH II

9-PORT 100-/1000-MBIT/S ETHERNET

SWITCH
SPWS044E – DECEMBER 1997 – REVISED AUGUST 1999
72
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
LED interface
LED (see Figure 29)
NO. MIN MAX UNIT
1 tc(LED_CLK) Cycle time, LED_CLK 8 tc
2 tw(LED_CLK) Pulse duration, LED_CLK high 4 tc
3 tn(LED_CLK) Number of LED_CLK pulses in burst 24†
4 tc(BURST) Cycle time, LED_CLK burst 4687488‡ tc
5 tsu(LED_DATA) Setup time, LED_DATA before LED_CLK ↑ 4 tc
6 th(LED_DATA) Hold time, LED_DATA after LED_CLK
↑
4 tc
† During hard reset, LED_CLK runs continuously.
‡ Does not apply during hard reset
First LED Second LED Last LED First LED
5
6
2
1
3
4
LED_CLK
LED_DATA
Figure 29. LED