Basic SPI coms

Development Boards MicroMod
1

I’m setting up a SPI coms between two lpc evaluation boards. One has a 12Mhz crystal and the other a 19.XX crystal. I have everything prety clear in my head and have written a lot of the code for it.

One thing I’m not sure about, and none of the data sheets seem to address is this. The master drives the clock signal at the programmed frequency, but on the slave does the frequency need to be programmed and to match, or does the slave just sync, provided the frequency falls under the pclk/8 rule ?

thanks,

Andy

2

Yes, the slave device will use the master clock as long as it’s within the stated frequency/8 limit.

3

Don’t make the cable too long. The clock signal is the most problematic signal. You must ensure that signal integrity is good.

Or use RS422 drivers.

Angelo