In reference to the translation of programs:

• Why isn't just one read of the source code (passed) by an assembler enough?
• What use is the opcode table to an assembler?
• What are forward and backward references?

Consider the RISC-V architecture.

• Describe the Program Counter update cycle.
• Please explain how the datapath must be configured for the “beq x11, x12, LABEL” operation to be performed.

In riferimento alle caratteristiche del livello ISA. Descrivere:

• Cosa si intende per “modalità di indirizzamento”?
• La differenza tra ordinamento little endian e big endian dei byte all’interno di una parola;
• Nell’architettura RISC-V, quali sono i tipi di registri? Perché ci sono diversi tipi?

Regarding buses:

• How do an active and a passive device interact in an asynchronous bus communication?
• Why is bus arbitration necessary?
• Explain what daisy chain bus arbitration is.

Consider the following two pieces of pseudocode:

// CODE 1: 
const int N =  ...;
 
int X [ n ] , Y [ N ] ;  // (sizeof(int) = 1 word) 
for  ( int i = 0 ; i < N ; i ++ )
 
    Y [ i ]  = X [ i ]  + i ; 
// CODE 2: 
const int N =  ...;
 
int X [ N ] , Y [ N ] ;  // (sizeof(int) = 1 word) 
for  ( int i = 0 ; i < N ; i ++ )
 
    Y [ i ]  = X [ 0 ]  + i ;
 

• Let us illustrate, in general, the concepts of spatial and temporal locality in the execution of programs.
• Which of the two code fragments exhibits greater locality of each kind?
• What happens if the processor wants to access a memory word already present in the cache? And what happens if it isn't present?
• What parameters should be considered when evaluating the performance of cache memories?
• In a cache-based architecture, which of the two code fragments results in a greater number of cache hits?