Recursion

Return address

Is the return address for a recursive function always the same at each function call?

A:

Important

ACV: access control violation exception. ACV exception occurs if a process attempts to access a location in privileged memory (system space or I/O page)

P131, In phase FETCH OPERAND, the MAR ← results of EVALUATE ADDRESS, and MDR ← M[MAR].

MAR is not loaded in phase EAVLUATE ADDRESS.

Microarchitecture of the LC-3

Overview

Data path

contains all the components that actually process the instructions.

Control

all the components that generate the set of control signals, to control the processing.

Clock Cycle

was provided with J, COND, IRD

Others

BEN: to indicate whether or not a BR should be taken. (Branch enable)

INT: .. higher PL than the current process

R: to indicate the end of a memory operation. E.g., MDR ← M[MAR], the state continues to execute until a ready signal from the memory (R) is asserted, indicating that the memory access has been completed.

State Machine

There are 52 signals specifying the state of the control structure / behaviors of the LC-3 microarchitecture by graph, called state machine.

One state for one clock.

P702

The Data Path

Data path: consists of all components that actually process the information during each clock cycle.