Remember me

Lost Password?

Register now!


Who's Online
73 user(s) are online (6 user(s) are browsing News)

Members: 0
Guests: 73



Recent Replied Topics
Topic Replies Last Post
AmigaOS4 SonosController - looking for beta testers 17 (593) khayoz Yesterday 23:50
AmigaOS4 Show keys on screen 5 (379) trgswe Yesterday 20:05
AmigaOS4 Reactive C Library 8 (414) rwo Yesterday 19:09
AmigaOS4 Exodus The Last War patching : v0.1 patch on os4depot [1][2][3][4] 79 (3056) kas1e Yesterday 17:42
AmigaOS4 Introducing Profyler [1][2][3] 41 (1939) Kamelito Yesterday 17:13
AmigaOS4 Getting Red Mars to run on AmigaOS 4.1 6 (277) LiveForIt Yesterday 16:03
AmigaOS4 X5000 - GfxBench2D score 4 (159) kas1e Yesterday 11:23
AmigaOS4 Nemo 7 (419) Raziel 1/27 20:47
AmigaOS4 Micro A1-C, overclocking, PCI cards, etc.. 12 (287) sailor 1/27 18:00
AmigaOS4 Is gprof ever works on os4 ? It is! And can be still! [1][2][3] 50 (2257) sTix 1/25 18:58
AmigaOS4 Are 4k screens supported by any AmigaNG compatible gfx-card? 9 (476) nbache 1/24 23:20
AmigaOS4 Cmake and adtools [1][2] 21 (2171) corto 1/24 21:18
AmigaOS4 Did anyone trying to port Valgrind ever ? 19 (5082) corto 1/24 21:05
AmigaOS4 SDL2 [1][2] ... [53][54][55][56] 1111 (332470) Capehill 1/24 18:50
Odyssey Odyssey 1.23 progress: r5 RC2 [1][2] ... [67][68][69][70] 1398 (486031) ktadd 1/23 20:16
[View all topics]  [Forum Settings]
Software News : Release of onchipmem.resource AmigaOS 4.1 component for Sam460ex
Posted by m3x on 2013/2/24 18:50:00 (1592 reads) News by the same author
Software News

ACube Systems announces the immediate release of the onchipmem.resource.
This is an OS4 component that provides access to the On Chip Memory (OCM) found on the APM460Ex SoC (used on the Sam460ex board for example).

The OCM buffer is 64KB in size, 128-bit bus width, and is much faster than main RAM, up to double the DDR2 speed, basically it has a speed similar to the 460Ex L2 cache.

It's main use is to store often accessed application data, or as a way to transfer more quickly a data buffer to/from video ram for example.

The archive contains documentation and example source code on how to use this resource.

The archive onchipmem_res.lha is available on OS4depot) (currently in upload queue) or on ACube Systems web site

Printer friendly page Send this story to a friend
The comments are owned by the author. We aren't responsible for their content.
Author Thread
Published: 2013/2/25 19:11  Updated: 2013/2/25 20:14
Amigans Defender
Joined: 11/17/2006
From: England
Comments: 3293
 Re: Release of onchipmem.resource AmigaOS 4.1 component f...
I was hoping this would have an AllocOnChipMem() function so it could work identically to main memory (perhaps with an ISONCHIPMEM macro to make it easy to identify which memory freeing function to use - as I'd intend to failover to main RAM).

Unfortunately, it looks like the entire 64KB has to be obtained and then manually micro-managed, which makes it somewhat more difficult to utilise effectively.

I have a little library that could potentially benefit from being able to use this speedy memory too. (edit: actually, it might benefit from a slightly different usage than I originally envisaged... let's see!)
Published: 2013/2/26 14:20  Updated: 2013/2/26 14:20
Just popping in
Joined: 12/01/2006
From: Anzio (Rome), Italy
Comments: 115
 Re: Release of onchipmem.resource AmigaOS 4.1 component f...

to me it seems overkill to implement a whole "alloc / free" functionality for just a 64 KB block, but if there is a real demand for such feature, I'll look into it.
Published: 2013/2/26 19:04  Updated: 2013/2/26 19:04
Not too shy to talk
Joined: 03/30/2007
Comments: 296
 Re: Release of onchipmem.resource AmigaOS 4.1 component f...
I love that. In the pure Amiga tradition, it is tried to get the best of the available resources.

Max: Is it possible to put code inside ?

I agree that an higher level access could be interesting but that's maybe too early and ... overkill as you said.

A technical question. It is as fast as L2 cache but do you think the drawback is that the L1 cache is not used there ?

Do you have usecases in mind, for which it would be appropriate ?

Thanks !
Published: 2013/2/26 19:23  Updated: 2013/2/26 19:23
Amigans Defender
Joined: 11/17/2006
From: England
Comments: 3293
 Re: Release of onchipmem.resource AmigaOS 4.1 component f...

Yes, you're probably right. In the meantime I've found a little memory pool routine which does exactly what I want (that is; allocate lots of little bits of memory that are the same size). I'm awaiting some feedback as to whether it helps performance in the wider context of the library (I'm a lowly SAM440EP owner, so can't test it myself).
Published: 2013/2/26 21:24  Updated: 2013/2/26 21:24
Just popping in
Joined: 07/16/2012
From: Istanbul
Comments: 229
 Re: Release of onchipmem.resource AmigaOS 4.1 component f...
Is it possible to use this feature to speed up software like AmiCygnix or Timberwolf ?
Published: 2013/2/26 21:49  Updated: 2013/2/26 21:49
Not too shy to talk
Joined: 03/30/2007
Comments: 296
 Re: Release of onchipmem.resource AmigaOS 4.1 component f...
m3x: I've found a usecase in the documentation itself, that says "Use as storage area for DMA descriptors and packet data for processing by Ethernet and Security Function."

But I am sure we can find other and more original uses

SinanSam460: Maybe it is possible but the first point is to know, in this programs or others, where are the part to speedup.
Published: 2013/2/27 10:43  Updated: 2013/2/27 10:43
Amigans Defender
Joined: 11/17/2006
From: England
Comments: 3293
 Re: Release of onchipmem.resource AmigaOS 4.1 component f...

Emulators might benefit from being able to put emulated registers on-chip. Some of the older emulated machines could have their entire RAM on-chip (I was toying with the idea of trying it with my ZX81 emulator, but it likely already runs at many times actual speed already, so I'm not sure the additional speed boost would be worthwhile). I might see if I can do something with ArcEm.

I'm playing around with this but it doesn't actually benefit me
Site sponsors
Advertise Here

Site statistics
Registered members
Logged in last:
  24 hours, 54
  7 days, 103
  30 days, 160

Top Posters
1 kas1e
kas1e 7346
2 Raziel
Raziel 4495
3 ChrisH
ChrisH 3564
4 samo79
samo79 3468
5 Chris
Chris 3293
6 orgin
orgin 3227
7 LiveForIt
LiveForIt 3054
8 328gts
328gts 2560
9 Antique
Antique 2503
10 broadblues
broadblues 2310

New Members
Evillord68 01/27/2022
msteed 01/18/2022
Torque 01/16/2022
djh0ffman 01/11/2022
amigaformortals 01/06/2022
r_amiga 12/20/2021
rjd324 12/20/2021
dessy 12/15/2021
mkegruber 12/13/2021
AJenbo 11/19/2021

Powered by XOOPS 2.0 © 2001-2016 The XOOPS Project