[Opendispense] Questions - new memory map

Adrian Chadd adrian@ucc.gu.uwa.edu.au
Wed Aug 13 17:06:14 2003


On Wed, Aug 13, 2003, Bernard Blackham wrote:
> On Mon, Aug 11, 2003 at 03:10:50PM +0800, Harry McNally wrote:
> > - Terminate the four wire wrap pitails on signals needed for read and
> >   write and full addressing (A15) onto the PCB.
> 
> So the questions remain, which 4 lines do we want to run up? Almost
> necessarily - A15, R/W, Enable. This leaves one more to choose from:
> 
>  - Interrupt line, possibly the most useful - but could use polling
>    instead.
> 
>  - Clock - running this line up here saves us a crystal on the
>    daughterboard for the UART. Though, we can probably afford
>    another crystal on the board.
> 
>  - Reset - to reset the state of the UART with the CPU. needed?
> 
> I'm leaning towards the interrupt line because it appears to make
> the serial comms that much more reliable. Any strong reasons for any
> of the others?

Depends how the software is written. Whats the current interrupt handler
doing?

Why can't you have em all?




Adrian