Views: 6,844,238 | Homepage | Main | Rules/FAQ | Memberlist | Active users | Last posts | Calendar | Stats | Online users | Search | 04-18-24 02:00 AM |
Guest: |
0 users reading About the ARM7 Coprocessor | 1 bot |
Main - General - About the ARM7 Coprocessor | Hide post layouts | New reply |
poudink |
| ||
Big melon Normal user Level: 28 Posts: 57/176 EXP: 118497 Next: 12841 Since: 03-30-17 From: Québec, Canada Last post: 559 days ago Last view: 344 days ago |
This isn't really about melonDS but moreso the DS hardware itself. As we know, the DS has an ARM7 coprocessor used for GBA backwards compatibility and handling things like audio and touch input. Well, that's how it was used in commercial games, anyway. My question is, is it actually limited to those tasks or could it be used for more complex tasks? To give a concrete example, could a homebrew emulator for the DS offload its CPU emulation to the ARM7 while emulating audio and the PPU on the ARM9? ____________________ Nothing to say, so jadnjkfmnjamnfjkldnajfnjkanfjdksan jsdnvj m. |
Generic aka RSDuck |
| ||
Big fire melon Administrator Level: 44 Posts: 89/592 EXP: 584994 Next: 26291 Since: 10-12-19 Last post: 14 days ago Last view: 14 hours ago |
For some potential optimisations I profiled the ARM7 usage in some commercial games and it seemed like it's often underutilised. Though I wouldn't declare these results as representative. ____________________ Take me to your heart / never let me go! "clearly you need to mow more lawns and buy a better pc" - Hydr8gon |
Hydr8gon |
| ||
Member Dragon Trainer Level: 8 Posts: 10/11 EXP: 1630 Next: 557 Since: 10-29-18 Last post: 897 days ago Last view: 169 days ago |
Technically you can run whatever you want on the ARM7, but accessing certain hardware must be done with the processor that its I/O registers are mapped to. For example, the ARM9 has access to the graphics engines, and the ARM7 has access to audio. You could manipulate audio data on the ARM9, but the ARM7 would still need to pass it to the hardware. Similarly, you could prepare a list of 3D geometry commands on the ARM7, but the ARM9 would need to send them to the geometry engine.
Most commercial games probably don't use the ARM7 much because they rely on Nintendo's SDK, which seems to prefer doing everything on the ARM9 whenever possible. If it wasn't for GBA backwards compatability, I bet they wouldn't have even included the ARM7 in the first place. |
Sorer |
| ||
Member Normal user Level: 23 Posts: 72/116 EXP: 60043 Next: 7680 Since: 12-21-17 Last post: 820 days ago Last view: 732 days ago |
I think someone should profile the DS version of Chrono Trigger I think It was supposed to be a GBA port that got converted to DS in the last minute (so it uses ARM7 the most). |
Generic aka RSDuck |
| ||
Big fire melon Administrator Level: 44 Posts: 90/592 EXP: 584994 Next: 26291 Since: 10-12-19 Last post: 14 days ago Last view: 14 hours ago |
Posted by Sorer I think it would still use the ARM9, because unless the games's code is written in ARM assembler and uses a ton of ARM7 quirks, there's no good reason not to go with the intended way. ____________________ Take me to your heart / never let me go! "clearly you need to mow more lawns and buy a better pc" - Hydr8gon |
Main - General - About the ARM7 Coprocessor | Hide post layouts | New reply |
Page rendered in 0.047 seconds. (2048KB of memory used) MySQL - queries: 29, rows: 87/87, time: 0.039 seconds. Acmlmboard 2.064 (2018-07-20) © 2005-2008 Acmlm, Xkeeper, blackhole89 et al. |