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Groups > comp.arch.embedded > #26227
| From | rickman <gnuarm@gmail.com> |
|---|---|
| Newsgroups | comp.arch.embedded |
| Subject | Re: Speaking of Multiprocessing... |
| Date | 2017-03-24 19:22 -0400 |
| Organization | A noiseless patient Spider |
| Message-ID | <ob49hb$r43$1@dont-email.me> (permalink) |
| References | (3 earlier) <lda9dc9mptoamo1l5es3ku2vm71setk14m@4ax.com> <ob2cck$cu5$1@dont-email.me> <0if9dc9uphm9mrvjjstp1s30ah5fdcfd4i@4ax.com> <ob3la6$hgb$1@dont-email.me> <ob4772$grc$1@dont-email.me> |
On 3/24/2017 6:42 PM, Dimiter_Popoff wrote: > On 24.3.2017 г. 19:36, rickman wrote: >> ... >> >> Why don't I want to add a bit per memory location? If that bit happens >> to be free, I'd be silly to let it go to waste. > > I am not sure a bit per reservation unit will work in a multiprocessor > environment (it certainly will on your single core design, obviously). > > Both the reserved address (range, typically) and the reserving processor > will need to know who reserved what. But this is just a "gut feeling", > I did not think seriously about it. >> >> Again, an abbreviation I don't know. What's a TAS? > > Test And Set, a classic 68k RMW opcoode. Read a byte (just byte size > allowed), adjust the Z flag (Z IIRC...) to the state of bit 7 (MSB), > then write the byte back with bit 7 set. While doing this the processor > provides some means (holds AS asserted on the 68k IIRC) such that the > access to the address can not be granted to another processor for the > entire duration of the TAS opcode. > > Looks like in your case a simple bset (again 68k lingo, bit test and > set, but on two separate memory accesses, potentially interruptible > by another bus master - not by a processor interrupt, it is a single > instruction) will do what you need. Not interruptible in any way, shape or form in my approach. The read and write happen in the same clock cycle - one of the beauties of having dual port memory in an FPGA. -- Rick C
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Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-23 18:38 -0400
Re: Speaking of Multiprocessing... Tim Wescott <seemywebsite@myfooter.really> - 2017-03-23 18:19 -0500
Re: Speaking of Multiprocessing... Don Y <blockedofcourse@foo.invalid> - 2017-03-23 16:26 -0700
Re: Speaking of Multiprocessing... Tim Wescott <seemywebsite@myfooter.really> - 2017-03-23 18:47 -0500
Re: Speaking of Multiprocessing... Don Y <blockedofcourse@foo.invalid> - 2017-03-23 17:49 -0700
Re: Speaking of Multiprocessing... upsidedown@downunder.com - 2017-03-24 09:48 +0200
Re: Speaking of Multiprocessing... Don Y <blockedofcourse@foo.invalid> - 2017-03-24 01:22 -0700
Re: Speaking of Multiprocessing... Clifford Heath <no.spam@please.net> - 2017-03-24 21:04 +1100
Re: Speaking of Multiprocessing... Robert Wessel <robertwessel2@yahoo.com> - 2017-03-24 22:01 -0500
Re: Speaking of Multiprocessing... Clifford Heath <no.spam@please.net> - 2017-03-25 18:49 +1100
Re: Speaking of Multiprocessing... Grant Edwards <invalid@invalid.invalid> - 2017-03-24 14:36 +0000
Re: Speaking of Multiprocessing... Robert Wessel <robertwessel2@yahoo.com> - 2017-03-23 22:43 -0500
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-24 01:05 -0400
Re: Speaking of Multiprocessing... Robert Wessel <robertwessel2@yahoo.com> - 2017-03-24 00:37 -0500
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-24 01:58 -0400
Re: Speaking of Multiprocessing... Robert Wessel <robertwessel2@yahoo.com> - 2017-03-24 02:07 -0500
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-24 13:36 -0400
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-24 19:06 +0100
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-24 14:12 -0400
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-25 01:48 +0100
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-24 22:10 -0400
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-25 15:25 +0100
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-25 15:27 -0400
Re: Speaking of Multiprocessing... upsidedown@downunder.com - 2017-03-25 22:43 +0200
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-25 17:06 -0400
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-26 17:28 +0200
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-26 13:27 -0400
Re: Speaking of Multiprocessing... Dimiter_Popoff <dp@tgi-sci.com> - 2017-03-25 00:42 +0200
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-24 19:22 -0400
Re: Speaking of Multiprocessing... Rob Gaddi <rgaddi@highlandtechnology.invalid> - 2017-03-24 16:33 -0700
Re: Speaking of Multiprocessing... Robert Wessel <robertwessel2@yahoo.com> - 2017-03-24 22:47 -0500
Re: Speaking of Multiprocessing... Dimiter_Popoff <dp@tgi-sci.com> - 2017-03-25 12:40 +0200
Re: Speaking of Multiprocessing... Robert Wessel <robertwessel2@yahoo.com> - 2017-03-26 00:42 -0500
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-24 09:17 +0100
Re: Speaking of Multiprocessing... Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-03-24 09:28 +0000
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-24 11:19 +0100
Re: Speaking of Multiprocessing... Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-03-24 11:06 +0000
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-24 12:21 +0100
Re: Speaking of Multiprocessing... Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-03-24 16:09 +0000
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-24 17:33 +0100
Re: Speaking of Multiprocessing... Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-03-24 17:52 +0000
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