On Thursday 16 April 2009 18:03:22 Ben Dooks wrote: > On Thu, Apr 16, 2009 at 05:43:18PM +0200, Gianluca Renzi wrote: > > Hello list, > > I would like to know if there is something wrong in my setup. > > I have a custom board s3c2442BL based. > > I ported some test points into a strip just to have an "expansion > > connector". Those pins are GPA12..GPA16. On reset they are at 1.8V is it > > normal? If I configure them as OUTPUT in GPACON register and write the > > corresponding bit High its level remains 1.8V not 3.3V. Is it normal? It > > looks like it has some PULLDOWN register enabled, but the GPIO A is the > > only port that *DOES NOT HAVE* such register (from port B to port J they > > have PD regs...) They are wired DIRECTLY from CPU pins to strip pins. No > > pullup, pulldown or whatever... > > are you sure these pins are referenced to VDDio, and not VDDmem? Yep. You are right. On page 261 on User's Manual it is written: (Note) The GPA21 Power is depend on VDDOP, the other pads(GPA0~20, GPA22~24) are all on VDDMOP. Where VDDOP means +3.3V and VDDMOP means +1.8V.
That clarify everything. Thanlks to all. Best regards, -- Gianluca Renzi R&D phone: +39.0542.609120 fax: +39.0542.609212
