Question

I’m working on a project where I sample a signal with an ADC, that represents values as 14 bit words. I need to scale the values to 8 bit words. What’s a good way to go about this in general. By the way, I’m using an FPGA so I’d like to do it in “hardware” rather than a software solution. Also in case you’re wondering the chain of events will be: sample analog signal, represent sample value with 14 bit word, scale 14 bit word to 8 bit word, transmit 8 bit word with UART to PC COM1.

I’ve never done this before. I was assuming you use quantization levels, but I’m not sure what an efficient circuit for this operation would be. Any help would be appreciated.

Thanks

Answer 1

You just need an add and a shift:

val_8 = (val_14 + 32) >> 6;

(The + 32 is necessary to get correct rounding – you can omit it but you will get more truncation noise in your signal if you do.)