add instruction system spec
Update op_codes.md
Update op_codes.md
Update op_codes.md
Update op_codes.md
add debug code
apply new instruction system
add the jmp family instruction
Merge branch 'master' of https://github.com/mad4alcohol/CPU_Exercise into mad4alcohol-master

Conflicts:
	op_codes.md
	src/decoder_2_to_4.vhd
	src/decoder_unit.vhd
	src/exe_unit.vhd
	src/exp_cpu.vhd
	src/exp_cpu_components.vhd
	src/instru_fetch.vhd
	src/mux_4_to_1.vhd
	src/regfile.vhd