Texas Instruments TMS380C26 - Manual (Page 60)

TMS380C26
NETWORK COMMPROCESSOR
SPWS010A–APRIL 1992–REVISED MARCH 1993
POST OFFICE BOX 1443
•
HOUSTON, TEXAS
77251–1443
60
PARAMETER MEASUREMENT INFORMATION
ethernet timing of XMIT signals
NO. PARAMETER MIN TYP MAX UNIT
350 JAMTIM
Time from COLL sampled high (TXC high) to first transmitted ”JAM” bit on TXD
(see Note 20)
4 cycles
351 COLSET Setup of COLL high before TXC high 20 ns
352 COLPUL Minimum pulse duration of COLL high for guaranteed sample 20 ns + 1 cycle ns
NOTE 20: The JAM pattern is delayed until after the completion of the preamble pattern. The TMS380C26 transmits a JAM pattern of all ”1”s.
350
TXC
TXD
COLL
Data Data Data JAM JAM JAM
351
352
Figure 27. Ethernet Timing of XMIT Signals