Hi all
I'm driving out of my F303K8 a continuous SPI sequence using transfer() of about 600 bytes long. Of course I didn't start with 600, I started by getting 1 through 8 working first. I want to use 5 bits of output per 'SPI byte' at 2 MHz. That's the goal.
The following setups show what I've tried, what works, and which combo does not give a continuous output. Instead, there is a curious gap in the clock and data.
2 Mhz, 5 bits per byte, 5 bytes total - works
2 MHz, 5 bits per byte, 7 bytes total - GAP BETWEEN 6th and 7th byte - renders my output useless
2 MHz, 8 bits per byte, 64 bytes total - works
1 MHz, 5 bits per byte, 8 bytes total - works
1 MHz, 5 bits per byte, 64 bytes total - works
Trace:
As you can see, the last byte (of five bits) is hanging off the right-hand side with a gap between it and its 6 earlier ones. Trace is aligned bang on the left hand side so it fits with the grid lines.
Does anyone have any ideas?
Continuous output is needed as a 150 nanosecond gap in the data is interpretted by my receiver as a break.
I've twiddled that FRF register - it's not that.
Thanks
RichColours
Hi all
I'm driving out of my F303K8 a continuous SPI sequence using transfer() of about 600 bytes long. Of course I didn't start with 600, I started by getting 1 through 8 working first. I want to use 5 bits of output per 'SPI byte' at 2 MHz. That's the goal.
The following setups show what I've tried, what works, and which combo does not give a continuous output. Instead, there is a curious gap in the clock and data.
Trace:
As you can see, the last byte (of five bits) is hanging off the right-hand side with a gap between it and its 6 earlier ones. Trace is aligned bang on the left hand side so it fits with the grid lines.
Does anyone have any ideas?
Continuous output is needed as a 150 nanosecond gap in the data is interpretted by my receiver as a break.
I've twiddled that FRF register - it's not that.
Thanks
RichColours