elaborate and simulate add_carry_ghdl_testbench
sci=1
sx_6_0=68.0
sy_6_0=38.0
sz_6_0=21.0
sco_6_0=1

sci=1
sx_3_m3=D.0
sy_3_m3=7.0
sz_3_m3=4.2
sco_3_m3=1

sci=1
sx_3_0=D.0
sy_3_m3=7.0
sz_3_0_m3=4.2
sco_3_0_m3=1