Fixed Point: cut, round, saturation?

[davyzhu]

Hi all,

I used to read FIR filter RTL implementation. I found they use a lot of cut(i.e. delete several LSB bits) , round(i.e. delete several LSB bits), and saturate to protect the data overflow.

I found they like to cut and saturate in the middle of the data path. And round at the end of the data path.

Is there any book talk about Fixed Point operation?
And is there any design tools?

Any suggestions will be appreciated!
Best regards,
Davy