How can I write 16-bit in SPI with a PI24FJ?

geolover · Joined: 08 Feb 2011 Posts: 18

I used a PIC24FJ128GA010 for my sensor project, I found that CCS compiler is able to set the SPI to 16-bit mode, however, spi_write command can only write 8-bit data, is there a way that I could get the PIC simply sending 16-bit data over the SPI without sending 8-bit data twice with SPI set to 8 bit mode?

Ttelmah · Joined: 11 Mar 2010 Posts: 19328

No.
This is all the CCS software does.

It is worth understanding that SPI, has a buffer register. There is the buffer, and the shift register. You can load a second byte into the buffer register, as soon as the first byte transfers to the shift register, so the two bytes are sent one after the other, just as if there was a 16bit write command.
However it doesn't matter even if there is a gap betwene bytes. The whole point about SPI, is that it includes a clock, so couldn't actually care if the data is sent one bit at a time, two bits at a time etc..

Best Wishes

FvM · Joined: 27 Aug 2008 Posts: 2337 Location: Germany

geolover · Joined: 08 Feb 2011 Posts: 18

FvM · Joined: 27 Aug 2008 Posts: 2337 Location: Germany

e.g.