media engine and sleep/resume psp

yoyofr · Post by **yoyofr** » Tue Feb 14, 2006 6:17 am

Hi all,

I've been using a lot the me lately and it's really a wonderful thing to play with!

My issue is it seems I cannot make the psp go to sleep mode when using it.
I've done batches of testings and it seems once you called (whatever you call after...) sceSysregMeResetEnable()

you cannot have sleep mode operating as usual. when it's triggered the psp starts to go sleeping, but you can notice the lcd backlight does not totally shuts off. moreover resuming is impossible, a hard reset is needed.

did someone manage to have me used & sleep mode operating ?

yoyofr · Post by **yoyofr** » Thu Feb 16, 2006 10:10 pm

still nobody ?

Brunni · Post by **Brunni** » Sun Feb 19, 2006 7:23 am

Yes, I had this problem also, but I gave up ME because it was not very useful.
The only interest I found is for playing an MP3 (not tried) or emulating additionnal chips like genesis' Z80 and YM2612, but even on that, I gave up (synchronization problems driving me crazy when the code became too big).
My guess is that ME goes in sleep mode trough its kernel (executes routine in flash or something like this), and so reseting it will make it fail...
Bon vu que mon anglais est pourri, j'en profite pour te féliciter en français pour ce que tu as fait (surtout avec le ME), c'est vraiment impressionnant :)

yoyofr · Post by **yoyofr** » Sun Feb 19, 2006 8:31 am

yeah, I thought it was related to reseting it too, so I tried to backup the overwritten ram area and then restoring it before going to sleep, but it doesn't work... I eventually was able to go to sleep mode but only after having trigerred a bus error (after restoring me overwritten ram and resetting it again). I guess I should try to reverse engineer a game (for ex lumines)...
perhaps later when everything else will be finished!

btw, me is really usefull for emulators, as can be the 3D chipset. but it requires rewriting lots of code and the sync issues can be really complex and easily get you crazy for sure :-)

brunni, ton anglais n'est pas plus mauvais que le mien et merci pour les encouragements! la version 0.4 de snes9XTYL aura tout le chipset son sur le me (d'ailleurs elle l'a deja dans ma version de dev...). par contre y a encore qqs pbs de syncro ce qui fait qu'au boot, quand la rom initialise le spc700 ca rame a fond! apres par contre, ca fuse!

Brunni · Post by **Brunni** » Mon Feb 20, 2006 6:06 am

I didn't go that far, so sorry I can't help you. Some time ago I tried quite a lot of things but nobody could help me there, and I quickly understood why they all had given up this idea ;)
I wonder if commercial games really use the ME as a second processor or if it's just preprogrammed by SONY with decompression & video routines and so on they can use...

Merci de ta réponse. Pour le SPC, je vois ce que tu veux dire, et je n'avais pas trouvé de solution pour mon z80 non plus. En tous cas c'est sympa à toi et ton équipe de continuer de bosser intensément sur cet ému, je sais que ça doit pas toujours être facile ;)

cheriff · Post by **cheriff** » Mon Feb 20, 2006 7:55 am

Brunni wrote:I wonder if commercial games really use the ME as a second processor or if it's just preprogrammed by SONY with decompression & video routines and so on they can use...

From what i've heard, commercial devs cannot run their own code on the ME at all. There presumably routines in the firmware/libs that provide for ADPCM decoding during gameplay, maybe more but i'm fairly sure custom code is a no-no. (for now anyway?)