Re: Assymmetry of setup and hold times
In a message dated 2/26/01 2:26:27 PM Pacific Standard Time,
Tom_Alexander@xxxxxxxxxxxxxx writes:
Hi, Justin,
It appears that Clause 51 D2.1 specifies assymmetrical setup/hold times for
the PMA
input timing (see Table 51.4) vs the PMA client input timing (see Table
51.8). For one
case it is 250 ps, while in the other case it is 300 ps. Is there some
reason behind this?
This seems to depart from the OIF SFI-4 spec. (Apologies in advance in case
I have
inadvertently raked up any heated discussions.)
Best regards,
- Tom Alexander
PMC-Sierra, Inc.
Hello Tom,
No heated discussions (I think) ... prior discussions was based on the
thinking that the PMA had better technology and could deal w/ smaller setup
and hold allowing the PMA client would be freedom for more setup and hold. I
would
say that given CMOS progress that we can make both symetrical and go for
the smaller 250ns setup. Allows more room for board and system budget.
This is something we can change for next time, TC on rev 2.2
Regards,
Justin Chang
Quake Technologies, Inc.
2880 Zanker Road, Suite 104
San Jose, CA 95134
Tel: 408-922-6888 x108
Fax: 408-922-6827
email: justin@xxxxxxxxxxxxx
internet: www.quaketech.com