ITEC 1000 Lecture Notes - Index Register, Program Counter, Addressing Mode

• School: York University
• Department: Information Technology
• Course: ITEC 1000
• Professor: All

Document Summary

Itec 1000 winter 2010 peter khaiter. Lecture 7 instruction addressing and programming tools feb 22. Direct: data is reached directly from the address in the instruction. Absolute: address in the instruction field is the actual memory location being addressed. Programmer-accessible registers: provide faster execution with register-based instructions. Alternatives to absolute addressing: allow larger range of addressable memory, while using a reasonable number of bits for the address field. Alternatives to direct addressing: facilitate writing certain types of programs, example: loops that use index to address different entries in a table or array. Implemented directly as part of the cpu: all registers are located in the cpu (as a part of alu or a separate register unit) Both provide starting address and an offset or displacement from the starting point: starting address in register or program counter, offset: address in the instruction.