1. Computer Architecture: Intro Anatomy of a CPU J. Schmalzel S. Mandayam

2. Hierarchical View of EP and Digital Systems CPUMEM I/O Gates Boolean Algebra Design Techniques MSI Functions State Machines Interface Method Computer Architecture Operating System HLLs

3. Block Diagram

4. Concept of CPU as Two Paths §Data Path l Where data elements flow from/to l Where operations are performed §Control Path l The source of data path control

5. Simple Model Data Path (7-18) Dbus n-bit bus Signal Dbus Dout Aout FS Status DA AA RW Const MB MD Register File Function Unit MuxB MuxD Din BA

6. Instruction Word DA AA BA MB FS MD RW 33311 5

7. Iword, cont. RW to write back result AA, BA, DA: 3-bit selection field to select 1-of-8 registers MB to select source operand for B path FS to select operation MD to select source for register file load RF FU

8. Function Select Codes 00000F=A 00001F=A+1 00010F=A+B 00011F=A+B+1 00100F=A+ ~B 00101F= A+ ~B + 1 00110F=A-1 00111F=A 01000F=A & B 01010F=A | B 01100F=A  B 01110F= ~A 10000F=B 10100F= sr B 11000F= sl B

9. FU (ALU) Design Approaches §Complex combinatorial structure §Multiplexed discrete logical and arithmetic units §HDL model

10. Consider Implementation §Use organization of FS codes to partition system (use FS4 and FS3): l 00-Arithmetic l 01-Logical l 10, 11-Shift, Miscellaneous

11. Questions, Comments, Discussion