06_CPU_Part2.pdf

Overview To execute instructions, the processor must have some means of generating the control signals needed in the proper sequence. Two categories: hardwired control and microprogrammed control Hardwired system can operate at high speed; but with little flexibility....

Overview To execute instructions, the processor must have some means of generating the control signals needed in the proper sequence. Two categories: hardwired control and microprogrammed control Hardwired system can operate at high speed; but with little flexibility. Hardwired Control Unit Control Unit Organization CLK Control step Clock counter External inputs Decoder/ IR encoder Condition codes Control signals Control unit organization. Detailed Block Description CLK Clock Control step Reset counter Step decoder T1 T2 Tn INS1 External INS2 inputs Instructio IR n Encoder decoder Condition codes INSm Run End  Generating Zin Zin = T1 + T6 ADD + T4 BR + … Branch Add T4 T6 T1 Generation of the Zin control signal for the processor in Figure 7.1.  Generating End End = T7 ADD + T5 BR + (T5 N + T4 N) BRN +… Branch