Ah, ah, that was a bait... While trying to understand why it didn't work, I compared USB ram on 18F4550, 18F14K50 and 18F27J53. USB ram can span onto specific banks (18F4550, 18F14K50) or all ram (18F27J53). Within USB ram, some is reserved for buffer descriptor tables (BDT), which actually defines some sort of registers with variable size within USB ram. Those locations vary from PIC to PIC. usb_defs.jal currently takes care of 14K50 and 4550, I'll update it for 27J53. But I was wondering if there was a way to make this more generic, maybe enriching these special locations in device files. I had a very quick look at 18f27j53.inc file in MAPSM, I can't find anything related to this, but you know this far better than me, so maybe you'll have an idea.
For 18F27J53, all ram can be used as USB ram, this means you can put buffer anywhere. But current jalv2 USB implementation assumes USB data is following BDT. For this PIC, memory is oragnized as (IIRC): USB data from bank 0 to 13, BDT and USB data on bank 14, USB data on bank 15. this means, with current implementation, only bank 15 can be used, as it's following BDT/bank 14. If we have information about this, maybe we could build a better, more generic USB lib set. So, to sum up: 1. is it possible to enrich device file with BDT memory location ? 2. is it possible to enrich device file with USB data memory location ? 1. would help setting USB_BASE_ADDRESS in usb_defs.jal in a more generic way. 2. really is an extra, using this type of information would require huge modifications in libraries. But also would allow to build heavy USB device. I'm not sure it's useful right now though... Cheers, Seb 2011/4/1 Rob Hamerling <[email protected]> > > Hi Seb, > > > On 2011/04/01 20:59, Sebastien Lelong wrote: > > During my USB "travel", I mentioned several issue regarding debug >> statement (see also issue 153). With the help of newfound from Microchip >> forums, I pointed another issue about USB base address (Rob, maybe we >> can work on this ?). I'll try to address both of these. >> > > I would be glad to help, but you'll have to tell me more how! > > Regards, Rob. > > -- > R. Hamerling, Netherlands --- http://www.robh.nl > > -- > You received this message because you are subscribed to the Google Groups > "jallib" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/jallib?hl=en. > > -- Sébastien Lelong http://www.sirloon.net http://sirbot.org -- You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jallib?hl=en.
