Path: utzoo!attcan!uunet!seismo!sundc!pitstop!texsun!texsun.central.sun.com!convex!authorplaceholder
From: gelsey@convex.UUCP
Newsgroups: comp.arch
Subject: Re: More On Write-Only Control Register
Message-ID: <63900018@convex>
Date: 21 Jun 88 22:53:00 GMT
References: <439@cf-cm.UUCP>
Lines: 17
Nf-ID: #R:cf-cm.UUCP:-43900:convex:63900018:000:620
Nf-From: convex.UUCP!gelsey    Jun 21 17:53:00 1988


Write-only registers have a number of advantages:
	1) Extremely fast
		Even a CMOS write-only register will operate in under a
		nanosecond.
	2) Very low power power dissipation
		Typically they draw in the sub-microamp region
	3) Very space efficient
		One can fit at least an order of magnitude of wo-registers
		in the same space as a rw-register.
	4) Readily available
		Any semiconductor salesman worth his salt will be happy to
		sell you a truckload full on a moment's notice.  Second
		sources are no problem.

These days most commercial computer designers attempt to use write-only
registers wherever possible.