TMS380C26

NETWORK COMMPROCESSOR

SPWS010A±APRIL 1992±REVISED MARCH 1993

PARAMETER MEASUREMENT INFORMATION

ethernet timing of RCV signals Ð end of frame

NO.

 

PARAMETER

MIN

TYP MAX

UNIT

 

 

 

 

 

 

320

CRSSET

Setup time of CRS low before RXC no longer low to determine if last data bit ºseenº on

20

 

ns

previous RXC no longer low (see Note 18)

 

 

 

 

 

 

 

 

 

 

 

 

321

CRSHLD

Hold time of CRS low after RXC no longer low, to determine if last data bit ºseenº on

0

 

ns

previous RXC no longer low

 

 

 

 

 

 

 

 

 

 

 

322

XTRCYC Number of extra RXC clock cycles after last data bit (CRS pin is low) (see Note 18)

0

5

cycle

NOTE 18: TMS380C26 will operate correctly even with no extra RXC clock cycles, providing that CRS does not remain asserted longer than 2 s (see timing spec, NDRXC). Providing no extra clocks affect receive startup timing, see timing spec, SAMDLY.

RXC

320

321

CRS

322

RXD

Last

Data Bit

Figure 24. Ethernet Timing of RCV Signals Ð End Of Frame

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Page 58
Image 58
Texas Instruments TMS380C26 Ethernet timing of RCV signals Ð end of frame, Crshld, 320 321, 322, Last Data Bit