Scaled 14-bit word for 8-bit word
I am working on a project where I tried a signal from an ADC that represents values as 14-bit words. I need to scale the values to 8 bit words. What a good way to do this in general. By the way, I am using FPGA, so I would like to do it in "hardware" and not in software solution. Also, if you're curious, the event chain would be: analog signal sample, represent an approximate value with a 14-bit word, scale a 14-bit word to an 8-bit word, send an 8-bit word from UART to PC COM1.
I've never done this before. I assumed you were using quantization levels, but I'm not sure how efficient the circuit would be for this operation. Any help would be greatly appreciated.
thank
You just need to add and shift:
val_8 = (val_14 + 32) >> 6;
( + 32
you need to get the correct rounding - you can omit it, but if you do this you get more truncation noise).
I think you just drop six bits at the lowest resolution and call it okay, right? But I might not fully understand the statement of the problem.
Paul's algorithm is correct, but you will need some bounds checks.
assign val_8 = (&val_14[13:5]) ? //Make sure your sum won't overflow
8'hFF : //Assign all 1 if it will
val_14[13:6] + val_14[5];