TAILIEUCHUNG - Lecture Introduction to computing systems: Chapter Introduction to Part II - Yale N. Patt, Sanjay J. Patel

After studying this lecture you will be able to understand: Higher level languages, translation, variables, activation records, function calls, returning from a call. | Introduction to Part II HLL Structures Variables Activation records Higher Level Languages HLLs allow symbolic naming of variables After mastering Assemly, you can now appreciate what a luxury this is! HLLs provide expressiveness Compare an if statement to a conditional Branch instruction! HLLs abstract from the underlying hardware While each microprocessor has its own ISA, HLL code is usually portable between many different platforms etc., etc. Pt. II - Translation HLL code has to be translated into the ISA of each machine it runs on: Interpretation: The HLL code is simply a set of commands for a program called an interpreter, which is a virtual machine that translates the HLL code a piece at a time into Machine Language, executes it on the spot, then goes back for another piece. Both the HLL source code and the interpreter are required every time the program is run. Compilation The HLL code is translated into an entire ML program (an executable image) by a program called a compiler. Only the executable image is needed to run the program. Most application software is sold in this form. Pt. II - Variables Symbolic names for variables The compiler creates a symbol table which holds information about each variable: Identifier (name), data type, memory location (as an offset from a “frame pointer”), scope, etc. Suppose a variable “seconds” has been assigned an offset of -5 from the frame pointer, which is maintained in R5: then we can access seconds by the Base+Offset addressing mode: LDR R0, R5, # -5 . each reference to the variable seconds is translated by the compiler to (R5) - 5 We have finally found a use for the offset in LDR! Pt. II - Activation Records A Record A collection of contiguous memory locations treated as one entity The struct construct in C/C++ describes a record Activation Record Is allocated for each function invocation in memory The area of memory where activation records are allocated is called the stack memory or run-time stack .

• Phần cứng
• Computing systems
• Introduction to computing systems
• Computing machines
• Computer organization
• General purpose computers
• General purpose computers
• Data types
• Decimal numbers
• Digital logic structures
• Electronic ones
• The von Neumann Model
• Instruction cycle
• Operate instructions
• Data movement instructions
• LC 2 assembly language
• Assembly language instructions
• Device registers
• I O basics
• TRAP routines
• Privileged instructions
• Stack data structure
• Interrupt I O
• LC 3 instruction set architecture
• LC 3 data path
• Problem solving
• Structured programming
• Machine architecture
• Unsigned integers
• Von Neumann machine
• Instruction set architecture