ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES

Presentación del tema: "ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES"— Transcripción de la presentación:

1 ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES
MAPA GENERAL MODOS DE DIRECCIONAMIENTO EJEMPLOS DE MODOS DE DIRECCIONAMIENTO EN LOS PROCESADORES INTEL 80X86 BIBLIOGRAFIA ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES

2 ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES
MAPA GENERAL ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES

3 DEPENDENCIA DEL MODO DE DIRECCIONAMIENTO GPRS ARCHITECTURE
El modo de direccionamiento puede ser especificado por Una constante Un registro Una posición de memoria (PC RELATIVE ADDRESSING). ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES

4 DIFERENTES MODOS DE DIRECCIONAMIENTO
Addressing modes Example Instruction Meaning When used Register Add R4,R3 R4 <- R4 + R3 When a value is in a register Immediate Add R4, #3 R4 <- R4 + 3 For constants Displacement Add R4, 100(R1) R4 <- R4 + M[100+R1] Accessing local variables Register deffered Add R4,(R1) R4 <- R4 + M[R1] Accessing using a pointer or a computed address Indexed Add R3, (R1 + R2) R3 <- R3 + M[R1+R2] Useful in array addressing: R1 - base of array R2 - index amount Direct Add R1, (1001) R1 <- R1 + M[1001] Useful in accessing static data Memory deferred Add R1 <- R1 + M[M[R3]] If R3 is the address of a pointer p, then mode yields *p Auto- increment Add R1, (R2)+ R1 <- R1 +M[R2] R2 <- R2 + d Useful for stepping through arrays in a loop. R2 - start of array d - size of an element Auto- decrement Add R1,-(R2) R2 <-R2-d R1 <- R1 + M[R2] Same as autoincrement. Both can also be used to implement a stack as push and pop  Scaled Add R1, 100(R2)[R3] R1<-R1+M[100+R2+R3*d] Used to index arrays. May be applied to any base addressing mode in some machines. Referencia: extractado de la Figura 2.5. Selection of addressing modes with examples, meaning, and usage. Computer Architecture A Quantitative Approach. Autor: Patterson Hennessy. ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES

5 EJEMPLOS EN LA ARQUITECTURA 80X86
Se presentan a continuación algunos ejemplos sobre la arquitectura 80x86 de INTEL y referenciadas a los modelos genéricos de direccionamiento. ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES

6 DIRECT ADDRESSING MODE
R1 <- R1 + M[1001] Useful in accessing static data Referencia: Figura No :80C186EA/80C188EA Microprocessor User’s Manual, INTEL ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES

7 REGISTER INDIRECT ADDRESSING MODE
Register deffered Add R4,(R1) R4 <- R4 + M[R1] Accessing using a pointer or a computed address Referencia: Figura No :80C186EA/80C188EA Microprocessor User’s Manual, INTEL ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES

8 ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES
BASED ADDRESSING MODE Displacement Add R4, 100(R1) R4 <- R4 + M[100+R1] Accessing local variables Referencia: Figura No :80C186EA/80C188EA Microprocessor User’s Manual, INTEL ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES

9 INDEXED ADDRESSING MODE
Displacement Add R4, 100(R1) R4 <- R4 + M[100+R1] Accessing local variables Referencia: Figura No :80C186EA/80C188EA Microprocessor User’s Manual, INTEL ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES

10 BASED INDEX ADDRESSING MODE
Indexed Add R3, (R1 + R2) R3 <- R3 + M[R1+R2] Useful in array addressing: R1 - base of array R2 - index amount Referencia: Figura No :80C186EA/80C188EA Microprocessor User’s Manual, INTEL ARQUITECTURA DE COMPUTADORES - I.S.A. - ADDRESSING MODES