RE: Clause 45: MDIO Electrical Specifications
Hi Nafea,
Even if the spec states 1.5 V HSTL, you do system vendors a big
favor if you design I/O's so they can operate with 1.5-1.8 V.
Many vendors "claim" HSTL and actually power I/Os
at 1.8V. Smart if you ask me.
-Curt-
-----Original Message-----
From: Nafea Bishara [mailto:nafea@galileo.co.il]
Sent: Tuesday, February 27, 2001 2:07 PM
To: Rabinovich, Rick
Cc: stds-802-3-hssg@ieee.org
Subject: Re: Clause 45: MDIO Electrical Specifications
Hi Rick
it is assumed that most systems will have a 1.5V supply because of the HSTL
drivers ( XGMII or other HSTL interfaces like SRAMs and SPI-4 buses)
in any case, any design done today will be in 0.18u geometry or smaller,
thus, u sure will have a 1.8V or lower supply on board
regards
-nafea
"Rabinovich, Rick" wrote:
To All,
Table 45-41 indicates a maximum VIH = 1.5V. Why is it so restrictive?
I suggest that the inputs should be resilient to LVTTL levels (3.3V
Nominal), otherwise system manufacturers will be forced to provide
additional voltages and logic to support a 2-wire management bus.
Cordially,
Rick Rabinovich
Hardware Group Lead Engineer
System Architect
Spirent Communications
26750 Agoura Road
Calabasas, CA 91302
Phone: 818-676-2476
Fax : 818-880-9293
Email: rick.rabinovich@spirentcom.com
--
Nafea
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