SSP/SPI on the LPC2478

Started by ostehaps01 March 30, 2009
Hallo

I do have a generic question about the SSP/SPI in the LPC2478. The user manual confuses me a bit.!!

SSP0/SPI can be used either as SSP and SPI. But the SSP can also run as SPI???

The SPP1 can also run SPI or what??

So why is there a seperate SPI chapter in the manual if the SSP0/1 both ca be used as SPI?

Can I assume that I can interface to SPI devices using SPP0 and SSP1??

/Thomas

An Engineer's Guide to the LPC2100 Series

Hi:

The LPC2478 has a separate SPI module, that shares the same pins with the SSP0 module.

The SSP module can work as a SPI, but it also has a FIFO for transmit and receive data.

You have the option to use the SPI module (no FIFO) or the SSP0 (with FIFO) in the same I/O pins.

SSP1 is a separate SSP module as well, that can be use to connect SPI devices.

Note that you can only have 2 SPI buses enabled at one time (either SPI and SSP1, or SSP0 and SSP1)

Regards,

Alex.

--- In l..., "ostehaps01" wrote:
>
> Hallo
>
> I do have a generic question about the SSP/SPI in the LPC2478. The user manual confuses me a bit.!!
>
> SSP0/SPI can be used either as SSP and SPI. But the SSP can also run as SPI???
>
> The SPP1 can also run SPI or what??
>
> So why is there a seperate SPI chapter in the manual if the SSP0/1 both ca be used as SPI?
>
> Can I assume that I can interface to SPI devices using SPP0 and SSP1??
>
> /Thomas
>

----Original Message----
From: l...
[mailto:l...] On Behalf Of ostehaps01
Sent: 30 March 2009 12:53 To: l...
Subject: [lpc2000] SSP/SPI on the LPC2478

> Hallo
>
> I do have a generic question about the SSP/SPI in the
> LPC2478. The user manual confuses me a bit.!!
>
> SSP0/SPI can be used either as SSP and SPI. But the SSP
> can also run as SPI???
>
> The SPP1 can also run SPI or what??
>
> So why is there a seperate SPI chapter in the manual if
> the SSP0/1 both ca be used as SPI?
>
> Can I assume that I can interface to SPI devices using
> SPP0 and SSP1??
>

It's very confusing.
I think the difference is, you can use the SSP modules to be SPI, SSI
and microwire.
But the SPI module can only ever be SPI.

Beware the Pin Connect Block, where it is not clear which signals are
from the SPI module and which are from the SSP modules. The signals
called "SCK/MISO/MOSI" are from SPI module and those called
"SCK0/MISO0/MOSI0" are from SSP. We spent a long time puzzling over why
the SPI was not working, eventually finding that the pin was connected
to SSP not SPI.

Yes you can use SSP0 and SSP1 to interface to SPI devices, if you set
the SSP into the correct mode.

--
Tim Mitchell