ECE 265 Lab 5: 4x 4 bit registers store signed values from [-8, 7]. A 12-bit input sequence performs operations as per:

ff xx yy zz iiii

ff:

00 - initialize for the input sequence values of: 00, 00, 00, 00, 0000 - resets all registers to 0

01 - Add the iiii to selected register yy and store in xx    

10 - Add yy + zz, store in xx. 

11 - Subtract: yy - zz, store in xx.