Re: [Sdcc-user] xinit and P89C668

[Maarten B. <sou...@ds...>]

Bolek,

You must implement _sdcc_external_startup() and inside that function 
you must enable internal ram (EXTRAM=0). From the datasheet it's 
unclear to me if the contents of P2 are used for MOVX @Rn 
instructions in ERAM, but I don't think so. There also does not seem to 
be another sfr for selecting the page which SDCC calls _XPAGE. So 
the best option is to make a copy of crtxinit.asm and adapt it to use the 
dual dptr. crtxinit.asm is in sdcc/device/lib/mcs51 of the source tree. If 
you use the win32 installer, download it from CVS through the web-
based CVS repository viewer.

Good luck,
Maarten

> I'm using in one project both P89C668 and P89lLPC932 (Philips).
> My problem is:
> 'xinit' emits hi adr on P2, but it makes unusable this port in
> minimalistic hardware implementation of P89C668 (Philips). I know,
> workaround is "--no-xinit-opt" and init().
> 
> Has anyone know how to implement user xinit?
> 
> Thanks in advance
> 
> Bolek