Lpc2000

--- In lpc2000@yahoogroups.com, "sebfr74" <sejacquemard@...> wrote:
>

> - My first problem is I don't find in the user manual what start the 
> SPI clock for a read. In other controler (ATMEL 89C51 for example, a 
> 0x00 write to the data register start the clock). 

I have not yet started my ARM SPI programs, but from the manual it
looks like a write to the SPI data register starts the transfer. 
Remember that SPI is just a circular shift register with one part in
the processor (usually 8 or 16 bits) and the rest in the SPI chip.  So
there are not separate reads and writes.  All transfers do both.

> - The second one is I have 8 clock bit on the SCLK line just at the 
> startup and before my first external interrupt (the one noramlly who 
> start the SPI read...). I don't understand why I have got these 8 
> clock bits ? 
SPI transfers are controlled by the number of clocks when select is
asserted, not the total number of clocks.  SPI even works with a free
running clock.  Maybe the clock starts before the first transfer.

After these clock the SPI seems to be blocked...

Your code has
S0SPCCR	= 20;
	
I think you want
S0SPCCR	= 0x20;	

Decimal 20 puts it in slave mode instead of master mode.

-- Bob H.