Lpc2000

I'm going to start writing an SPI driver for the Philips LPC2106 
micro controller, but before doing so I wanted to check if no one 
else has done this so… if anyone has, please let me know.

Teun

Hi All

Just a quick question about SPI.

Today I tried to use it for the first time but had no luck. Possibly 
someone has a tip.

Here's what I am doing:
1. Set SPI ports for SPI operation
     *(unsigned long*)*0xe002C000 |= 0x00000050 // PINSEL0
2. Setup SPI speed
     *(unsigned long*)*0xe002000C = 0x00000020  // SPCCR
3. Setup SPI to master mode
     *(unsigned long*)*0xe0020000 |= 0x00000020  // SPCCR 
4. Send a test byte    
     *(unsigned long*)*0xe0020008 = 0x00000055  // SPDR

After the last command the status register has the bit 0x80 (SPIF) 
set to 1, indicating that the transfer has completed (before it was 
at 0), but I see no data sent (neither signals on the clock line nor 
the data line nor the SSEL line). In fact they all seem to be in a 
high impedence state since I measure zero voltage (or 3V3 with a 
pull up resistor).

Therefore I conclude that I have problems setting the SPI ports to 
the correct mode but PINSEL0 seems to be correct (which I have 
verified several times to be sure).

So what is the trick involved to get it working?

Thanks in advance

regards

Mark Butcher

www.mjbc.ch

At 05:07 PM 2/23/05 +0000, Mark Butcher wrote:
>After the last command the status register has the bit 0x80 (SPIF)
>set to 1, indicating that the transfer has completed (before it was
>at 0), but I see no data sent (neither signals on the clock line nor
>the data line nor the SSEL line). In fact they all seem to be in a
>high impedence state since I measure zero voltage (or 3V3 with a
>pull up resistor).
>
>Therefore I conclude that I have problems setting the SPI ports to
>the correct mode but PINSEL0 seems to be correct (which I have
>verified several times to be sure).
>
>So what is the trick involved to get it working?


SSEL must a - be an input and b - be pulled high.

See http://www.open-research.org.uk/ARMuC/index.cgi?LPC2100Tips

Robert

" 'Freedom' has no meaning of itself.  There are always restrictions,
be they legal, genetic, or physical.  If you don't believe me, try to
chew a radio signal. "

                         Kelvin Throop, III

Thank you Robert

The pull up on SSEL cured the problem!!

Regards

Mark Butcher


--- In lpc2000@yahoogroups.com, Robert Adsett <subscriptions@a...> 
wrote:
> At 05:07 PM 2/23/05 +0000, Mark Butcher wrote:
> >After the last command the status register has the bit 0x80 (SPIF)
> >set to 1, indicating that the transfer has completed (before it 
was
> >at 0), but I see no data sent (neither signals on the clock line 
nor
> >the data line nor the SSEL line). In fact they all seem to be in a
> >high impedence state since I measure zero voltage (or 3V3 with a
> >pull up resistor).
> >
> >Therefore I conclude that I have problems setting the SPI ports to
> >the correct mode but PINSEL0 seems to be correct (which I have
> >verified several times to be sure).
> >
> >So what is the trick involved to get it working?
> 
> 
> SSEL must a - be an input and b - be pulled high.
> 
> See http://www.open-research.org.uk/ARMuC/index.cgi?LPC2100Tips
> 
> Robert
> 
> " 'Freedom' has no meaning of itself.  There are always 
restrictions,
> be they legal, genetic, or physical.  If you don't believe me, try 
to

> chew a radio signal. "
> 
>                          Kelvin Throop, III

Hi Mark,

	I am having similar issue with the 2119 part where I noticed your PINSEL0
setting of 0x00000050 is misaligned with p78 or P127 of the 2119 user
manual. I'm I reading the table incorrectly? I register the value of
0x00001505 to have SPI 0 and UART 0 selected. But hey, mine is not
working...

Help anyone??

Regards

Ronnie Leighty
Principle Engineer
2802 Leslie Rd
Tampa, FL 33619
voice (813) 630-1229 ext. 111
fax     (813) 630-2619

-----Original Message-----
From: Mark Butcher [mailto:M_J_Butcher@...]
Sent: Wednesday, February 23, 2005 12:07 PM
To: lpc2000@yahoogroups.com
Subject: [lpc2000] SPI on LPC2106




Hi All

Just a quick question about SPI.

Today I tried to use it for the first time but had no luck. Possibly
someone has a tip.

Here's what I am doing:
1. Set SPI ports for SPI operation
     *(unsigned long*)*0xe002C000 |= 0x00000050 // PINSEL0
2. Setup SPI speed
     *(unsigned long*)*0xe002000C = 0x00000020  // SPCCR
3. Setup SPI to master mode
     *(unsigned long*)*0xe0020000 |= 0x00000020  // SPCCR
4. Send a test byte
     *(unsigned long*)*0xe0020008 = 0x00000055  // SPDR

After the last command the status register has the bit 0x80 (SPIF)
set to 1, indicating that the transfer has completed (before it was
at 0), but I see no data sent (neither signals on the clock line nor
the data line nor the SSEL line). In fact they all seem to be in a
high impedence state since I measure zero voltage (or 3V3 with a
pull up resistor).

Therefore I conclude that I have problems setting the SPI ports to
the correct mode but PINSEL0 seems to be correct (which I have
verified several times to be sure).

So what is the trick involved to get it working?

Thanks in advance

regards

Mark Butcher

www.mjbc.ch







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