[net.arch] Fast RAM with a "clear" pin

campbell@sauron.UUCP (Mark Campbell) (12/10/85)

Has anyone out there heard of fast (less than 40ns) RAM
with a "clear" pin (excluding the TI TMS chip)?  What I
am trying to do is to locate an alternative to the TMS
chip for implementing a cache.  Given the length of time
the TMS chip has been on the market, its high cost, the
fact that it is single-sourced, and the fact that it has
never been improved, it seems that SOMEONE out there
would have implemented an alternative.

If you have any information, please let me know, either
through mail or by posting.  Thanks ahead of time.
-- 

Mark Campbell
Phone:  (803)-791-6697
E-Mail: {decvax!mcnc, ihnp4!msdc}!ncsu!ncrcae!sauron!campbell

rae@alice.UucP (Rae McLellan) (12/13/85)

AMD's 9150 is a 1Kx4 static ram with a clear pin
and comes in 3 speeds, 45, 35, and 25nS access.
also rumored is a similar part coming from cypress.
(with luck it might be pin-compatible)

Then again, such designs might soon be replaced by a single
cache chip.  Does Fairchild have any plans of selling the
clipper cache chip as a separate component?

	Rae McLellan
	research!rae

bcase@uiucdcs.CS.UIUC.EDU (12/13/85)

AMD has a clearable RAM, the Am9150 I think, which is, I believe,
1K x 8.  However, the AMD RAM does not have the output comparator
that the TI TMS2150 has.  I think the 9150 is faster as well....
I have used the TMS2150 and like it; I have no exerience with the
Am9150.  There may be others....

wall@fortune.UUCP (Jim Wall) (12/13/85)

   I knew their was one somewhere. AMD makes the Am9150,
a 1K x 4  high speed static with a memory reset feature.
In only two cycle times the entire memory contents will 
be zeroed out. 

   Other details: 24 pin skinny dip, 25 nsec access, 5 volt
operation, 900 mwatt power consumption.

   We did a MMU design with this to compare it with other
options; and the other options won. But not for technical
reasons. They make a great basis for a paged MMU, without
using the TI 2150's. Although the 2150's reduce the logic so
much, it makes the single sourcing palatable.

					-Jim Wall
					Fortune Systems Corp.

				...amd!fortune!wall