Texas Instruments TMS380C26 - Manual (Page 59)

TMS380C26
NETWORK COMMPROCESSOR
SPWS010A–APRIL 1992–REVISED MARCH 1993
POST OFFICE BOX 1443
•
HOUSTON, TEXAS
77251–1443
59
PARAMETER MEASUREMENT INFORMATION
ethernet timing of RCV signals — no RXC
NO. PARAMETER MIN TYP MAX UNIT
330 NORXC Time with no clock pulse on RXC, when CRS is high (see Note 19) 2 µ s
NOTE 19: If NORXC is exceeded local clock failure circuitry may become activated, resetting the device.
CRS ”1”
RXC
330
Figure 25. Ethernet Timing of RCV Signals — No RXC
ethernet timing of XMIT signals
NO. PARAMETER MIN TYP MAX UNIT
340 HBWIN
Delay time from TXC high of the last transmitted data bit (TXEN is high) to COLL
sampled high, so not to generate a ”heart-beat” error
47 cycles
341 COLPUL Minimum pulse duration of COLL high for guaranteed sample 20 ns + 1 cycle ns
342 COLSET Setup of COLL high to TXC high 20 ns
TXC
TXD
TXEN
COLL
340
341
342
Figure 26. Ethernet Timing of XMIT Signals