topic Re: LPC17xx SCK1 signal in LPC Microcontrollers

LPC17xx SCK1 signal

lpcware — Wed, 15 Jun 2016 17:36:45 GMT

Content originally posted in LPCWare by blasiis on Thu Oct 30 07:47:13 MST 2014
Dear all.
I need to use the SSP interface for red/write to a SSD card.
Can I connect the SSD to SSP1 pins ?
My doubt is caused by a sentence in the user manual UM10360 on page 422.
" SCK1 only switches during a data transfer. "

What do you mean?
This thing only happens to sck1 and no SCK0?

Thanks

Stefano

Re: LPC17xx SCK1 signal

lpcware — Wed, 15 Jun 2016 17:36:45 GMT

Content originally posted in LPCWare by Alex on Thu Oct 30 07:54:10 MST 2014
Why don't you use the SD card interface?

Re: LPC17xx SCK1 signal

lpcware — Wed, 15 Jun 2016 17:36:46 GMT

Content originally posted in LPCWare by LabRat on Thu Oct 30 07:59:51 MST 2014

Quote: blasiis
My doubt is caused by a sentence in the user manual UM10360 on page 422.
" SCK1 only switches during a data transfer. "

What do you mean?
This thing only happens to sck1 and no SCK0?

OMG :O

So this clock isn't always active :quest:

You should read something about SPI / SSP and learn how it works...

https://learn.sparkfun.com/tutorials/serial-peripheral-interface-spi

http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus

Re: LPC17xx SCK1 signal

lpcware — Wed, 15 Jun 2016 17:36:47 GMT

Content originally posted in LPCWare by blasiis on Thu Oct 30 08:00:09 MST 2014
Maybe I'm wrong, but in the 17xx there isn't a SD interface .
What do you mean with SD interface ?

Re: LPC17xx SCK1 signal

lpcware — Wed, 15 Jun 2016 17:36:47 GMT

Content originally posted in LPCWare by LabRat on Thu Oct 30 08:06:33 MST 2014

Quote: blasiis
Maybe I'm wrong, but in the 17xx there isn't a SD interface.

Yes, you are. LPC177x and LPC178x have SD card interface...

Perhaps you should mention that you are using LPC175x or LPC176x....

Re: LPC17xx SCK1 signal

lpcware — Wed, 15 Jun 2016 17:36:48 GMT

Content originally posted in LPCWare by blasiis on Thu Oct 30 08:12:24 MST 2014
I know the protocol SPI MOSI / MISO and clock .
The clock changes state when the data is stable (normaly ad the center).
My question is on the phrase " sck1 only" because only? The device SCK0 how it behaves ?

Re: LPC17xx SCK1 signal

lpcware — Wed, 15 Jun 2016 17:36:49 GMT

Content originally posted in LPCWare by Alex on Thu Oct 30 08:23:44 MST 2014
Are you sure you can interface a SD card using the SSP?
As far as I know a SD card has 4 data lines + clock + command line...

The SSP has one chip select, two data lines and a clock line.

This is the feature list of the SSP:
Compatible with Motorola SPI, 4-wire TI SSI, and National Semiconductor Microwire buses.
Synchronous Serial Communication.
Master or slave operation.
8 frame FIFOs for bothtransmit and receive.
4 to 16 bit data frame.
DMA transfers supported by GPDMA

There is nothing about memory cards...

Re: LPC17xx SCK1 signal

lpcware — Wed, 15 Jun 2016 17:36:49 GMT

Content originally posted in LPCWare by dbtayl on Thu Oct 30 08:27:38 MST 2014
SD/MMC cards actually do have an SPI interface. Not sure why you'd use it when the micro has the MCI, but whatever works, I guess.

Re: LPC17xx SCK1 signal

lpcware — Wed, 15 Jun 2016 17:36:50 GMT

Content originally posted in LPCWare by blasiis on Thu Oct 30 08:38:18 MST 2014
In fact, I use the SSP as SPI
I cannot use the SPI direct because the SPI PIN is busy in my project, and than I try to use the SSP pin.