Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.arch.embedded > #30725
| From | Don Y <blockedofcourse@foo.invalid> |
|---|---|
| Newsgroups | comp.arch.embedded |
| Subject | Re: 64-bit embedded computing is here and now |
| Date | 2021-06-12 12:40 -0700 |
| Organization | A noiseless patient Spider |
| Message-ID | <sa32kd$44r$1@dont-email.me> (permalink) |
| References | (4 earlier) <s9nir0$k47$1@dont-email.me> <s9p24n$tp2$1@dont-email.me> <s9ppv5$vn3$1@dont-email.me> <s9q46j$qbj$1@dont-email.me> <hln9cg1vnhe9avl339ilnhb48c38rr8uje@4ax.com> |
Hi George, On 6/12/2021 9:58 AM, George Neuner wrote: > On Wed, 9 Jun 2021 03:12:12 -0700, Don Y <blockedofcourse@foo.invalid> > wrote: > >> On 6/9/2021 12:17 AM, David Brown wrote: >> >>> Process geometries are not targeted at 64-bit. They are targeted at >>> smaller, faster and lower dynamic power. In order to produce such a big >>> design as a 64-bit cpu, you'll aim for a minimum level of process >>> sophistication - but that same process can be used for twice as many >>> 32-bit cores, or bigger sram, or graphics accelerators, or whatever else >>> suits the needs of the device. >> >> They will apply newer process geometries to newer devices. >> No one is going to retool an existing design -- unless doing >> so will result in a significant market enhancement. >> >> Why don't we have 100MHz MC6800's? > > A number of years ago somebody had a 200MHz 6502. Granted, it was a > soft core implemented in an ASIC. > > No idea what it was used for. AFAICT, the military still uses them. I know there was a radhard 8080 (or 8085?) made some years back. I suspect it would just be a curiosity piece, though. You'd need < 10ns memory to use it in its original implementation. Easier to write an emulator and run it on a faster COTS machine! >>> But you are absolutely right about maths (floating point or integer) - >>> having 32-bit gives you a lot more freedom and less messing around with >>> scaling back and forth to make things fit and work efficiently in 8-bit >>> or 16-bit. And if you have floating point hardware (and know how to use >>> it properly), that opens up new possibilities. >>> >>> 64-bit cores will extend that, but the step is almost negligable in >>> comparison. It would be wrong to say "int32_t is enough for anyone", >>> but it is /almost/ true. It is certainly true enough that it is not a >>> problem that using "int64_t" takes two instructions instead of one. >> >> Except that int64_t can take *four* instead of one (add/sub/mul two >> int64_t's with 32b hardware). > > A 32b CPU could require a dozen instructions to do 64b math depending > on whether it has condition flags, whether math ops set the condition > flags (vs requiring explicit compare or compare/branch), and whether > it even has carry aware ops [some chips don't] > > If detecting wrap-around/overflow requires comparing the result > against the operands, multi-word arithmetic (even just 2 words) > quickly becomes long and messy. If you look back to life with 8b registers, you understand the pain of even 32b operations. Wider architectures make data manipulation easier. Bigger *address* spaces (wider address buses) make it easier to "do more". So, an 8b CPU with extended address space (bank switching, etc.) can tackle a bigger (more varied) problem (at a slow rate). But a wider CPU with a much smaller address space can handle a smaller (in scope) problem at a much faster rate (all else being equal -- memory speed, etc.) When doing video games, this was a common discussion (price sensitive); do you move to a wider processor to gain performance? or, do you move to a faster one? (where you put the money changes)
Back to comp.arch.embedded | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
64-bit embedded computing is here and now James Brakefield <jim.brakefield@ieee.org> - 2021-06-07 07:47 -0700
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-07 14:13 -0700
Re: 64-bit embedded computing is here and now Paul Rubin <no.email@nospam.invalid> - 2021-06-07 22:31 -0700
Re: 64-bit embedded computing is here and now David Brown <david.brown@hesbynett.no> - 2021-06-08 07:59 +0200
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-08 00:39 -0700
Re: 64-bit embedded computing is here and now David Brown <david.brown@hesbynett.no> - 2021-06-08 13:04 +0200
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-08 17:30 -0700
Re: 64-bit embedded computing is here and now David Brown <david.brown@hesbynett.no> - 2021-06-09 09:17 +0200
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-09 03:12 -0700
Re: 64-bit embedded computing is here and now George Neuner <gneuner2@comcast.net> - 2021-06-12 12:58 -0400
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-12 12:40 -0700
Re: 64-bit embedded computing is here and now Paul Rubin <no.email@nospam.invalid> - 2021-06-09 09:41 -0700
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-09 10:12 -0700
Re: 64-bit embedded computing is here and now DJ Delorie <dj@delorie.com> - 2021-06-09 13:16 -0400
Re: 64-bit embedded computing is here and now Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2021-06-09 13:44 -0400
Re: 64-bit embedded computing is here and now Dimiter_Popoff <dp@tgi-sci.com> - 2021-06-09 22:03 +0300
Re: 64-bit embedded computing is here and now Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2021-06-09 15:22 -0400
Re: 64-bit embedded computing is here and now Paul Rubin <no.email@nospam.invalid> - 2021-06-09 12:58 -0700
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-09 16:26 -0700
Re: 64-bit embedded computing is here and now Dimiter_Popoff <dp@tgi-sci.com> - 2021-06-09 23:12 +0300
Re: 64-bit embedded computing is here and now James Brakefield <jim.brakefield@ieee.org> - 2021-06-08 12:38 -0700
Re: 64-bit embedded computing is here and now David Brown <david.brown@hesbynett.no> - 2021-06-08 22:11 +0200
Re: 64-bit embedded computing is here and now James Brakefield <jim.brakefield@ieee.org> - 2021-06-08 14:25 -0700
Re: 64-bit embedded computing is here and now George Neuner <gneuner2@comcast.net> - 2021-06-09 00:16 -0400
Re: 64-bit embedded computing is here and now David Brown <david.brown@hesbynett.no> - 2021-06-09 10:40 +0200
Re: 64-bit embedded computing is here and now Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2021-06-09 22:52 +0200
Re: 64-bit embedded computing is here and now David Brown <david.brown@hesbynett.no> - 2021-06-10 09:37 +0200
Re: 64-bit embedded computing is here and now Dimiter_Popoff <dp@tgi-sci.com> - 2021-06-09 01:01 +0300
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-08 18:29 -0700
Re: 64-bit embedded computing is here and now Dimiter_Popoff <dp@tgi-sci.com> - 2021-06-09 20:56 +0300
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-09 17:12 -0700
Re: 64-bit embedded computing is here and now Dimiter_Popoff <dp@tgi-sci.com> - 2021-06-10 13:45 +0300
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-10 06:55 -0700
Re: 64-bit embedded computing is here and now Dimiter_Popoff <dp@tgi-sci.com> - 2021-06-10 18:32 +0300
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-10 14:09 -0700
Re: 64-bit embedded computing is here and now Dimiter_Popoff <dp@tgi-sci.com> - 2021-06-11 01:13 +0300
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-10 21:55 -0700
Re: 64-bit embedded computing is here and now Dimiter_Popoff <dp@tgi-sci.com> - 2021-06-11 14:14 +0300
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-11 05:10 -0700
Re: 64-bit embedded computing is here and now Dimiter_Popoff <dp@tgi-sci.com> - 2021-06-11 16:35 +0300
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-11 16:24 -0700
Re: 64-bit embedded computing is here and now George Neuner <gneuner2@comcast.net> - 2021-06-14 05:41 -0400
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-08 16:51 -0700
Re: 64-bit embedded computing is here and now Paul Rubin <no.email@nospam.invalid> - 2021-06-08 18:20 -0700
Re: 64-bit embedded computing is here and now Theo <theom+news@chiark.greenend.org.uk> - 2021-06-09 18:07 +0100
Re: 64-bit embedded computing is here and now Paul Rubin <no.email@nospam.invalid> - 2021-06-09 10:34 -0700
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-09 16:37 -0700
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-09 16:43 -0700
Re: 64-bit embedded computing is here and now Theo <theom+news@chiark.greenend.org.uk> - 2021-06-08 15:46 +0100
Re: 64-bit embedded computing is here and now David Brown <david.brown@hesbynett.no> - 2021-06-08 22:18 +0200
Re: 64-bit embedded computing is here and now Dimiter_Popoff <dp@tgi-sci.com> - 2021-06-08 23:39 +0300
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-08 18:33 -0700
Re: 64-bit embedded computing is here and now David Brown <david.brown@hesbynett.no> - 2021-06-09 10:59 +0200
Re: 64-bit embedded computing is here and now Dimiter_Popoff <dp@tgi-sci.com> - 2021-06-09 21:00 +0300
Re: 64-bit embedded computing is here and now David Brown <david.brown@hesbynett.no> - 2021-06-09 20:55 +0200
Re: 64-bit embedded computing is here and now Dimiter_Popoff <dp@tgi-sci.com> - 2021-06-09 22:06 +0300
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-08 16:00 -0700
Re: 64-bit embedded computing is here and now Theo <theom+news@chiark.greenend.org.uk> - 2021-06-09 13:10 +0100
Re: 64-bit embedded computing is here and now Don Y <blockedofcourse@foo.invalid> - 2021-06-09 06:19 -0700
csiph-web