topic Re: SPI driver in LPC Microcontrollers

SPI driver

lpcware — Wed, 15 Jun 2016 20:22:00 GMT

Content originally posted in LPCWare by rogerwilson on Wed Sep 30 06:30:24 MST 2015
Hi,

Is there any explanatory notes regarding how the SPI driver is supposed to work please? I'm having a hard time figuring out how Chip_SSP_Int_RWFrames8Bits(...) works when used in the SPI example code. It looks like it would run OK without the ISR but doesn't. Also why does the ISR contain a call to Chip_SSP_Int_RWFrames8Bits(...) ? The ISR seems to be run once per bit. I'm confused and wondered if there was any helpful notes somewhere.

TIA,

Rog.

Re: SPI driver

lpcware — Wed, 15 Jun 2016 20:22:01 GMT

Content originally posted in LPCWare by R2D2 on Wed Sep 30 06:48:37 MST 2015

Quote: rogerwilson
I'm confused and wondered if there was any helpful notes somewhere.

And I'm confused which MCU we are talking about :~

Re: SPI driver

lpcware — Wed, 15 Jun 2016 20:22:01 GMT

Content originally posted in LPCWare by rogerwilson on Wed Sep 30 08:12:56 MST 2015
Sorry, vital information left out there!

It's an LPC1113/302.

Thanks,

Rog.

Re: SPI driver

lpcware — Wed, 15 Jun 2016 20:22:02 GMT

Content originally posted in LPCWare by rocketdawg on Thu Oct 01 06:50:06 MST 2015

Quote: rogerwilson
Hi,
The ISR seems to be run once per bit. I'm confused and wondered if there was any helpful notes somewhere.
Rog.

No, it cannot do that. This part has a FIFO and table of section 14.6.6/7 of UM10398 refers to the conditions upon which an interrupt may occur. Once per bit is not one of them. Section 14.7 explains the functional description. LPCOpen does abstract away much of the hardware specifics, but if one needs to know, then the User Manual is your reference.

Re: SPI driver

lpcware — Wed, 15 Jun 2016 20:22:02 GMT

Content originally posted in LPCWare by rogerwilson on Thu Oct 01 13:01:27 MST 2015
Thanks for your interest.

I agree but according to my debugger experiments, it was. I know the UM very well to say the least but it's the LPC driver code that's a mystery. I've actually given up in the Int version and am using the Blocking version now. They seem so similar and can't understand what the difference in operation is so that'll do for my application. It's just a shame there's no documentation at all (online or otherwise) which would help.

Rog.