Assembler
Question 1 |
State whether the following statements are True or False with reasons for your answer:
(a) Coroutine is just another name for a subroutine.
(b) A two pass assembler uses its machine opcode table in the first pass of assembly.
Theory Explanation. |
Question 2 |
The pass number for each of the following activities
- 1. Object code generation
2. Literals added to literal table
3. Listing printed
4. Address resolution of local symbols
That occur in a two pass assembler respectively are
1, 2, 1, 2 | |
2, 1, 2, 1 | |
2, 1, 1, 2 | |
1, 2, 2, 2 |
Question 2 Explanation:
The functionalities from pass 1 and pass 2 are:
Pass 1:
1) Assign addresses to all statements in the program.
2) Save the values assigned to all labels for use in pass 2.
3) Perform some processing of assembler directives.
Pass 2:
1) Assemble instructions.
2) Generate data values defined by BYTE, WORD etc.
3) Perform processing of assembler directives not done during pass 1.
4) Write the program and assembling listing.
Pass 1:
1) Assign addresses to all statements in the program.
2) Save the values assigned to all labels for use in pass 2.
3) Perform some processing of assembler directives.
Pass 2:
1) Assemble instructions.
2) Generate data values defined by BYTE, WORD etc.
3) Perform processing of assembler directives not done during pass 1.
4) Write the program and assembling listing.
Question 3 |
A simple two-pass assembler does the following in the first pass:
It allocates space for the literals. | |
It computes the total length of the program | |
It builds the symbol table for the symbols and their values. | |
It generates code for all the load and store register instructions. | |
A, B and C |
Question 3 Explanation:
Pass 1:
1) Assign address to all statements in the program.
2) Save the values assigned to all tables for use in pass 2.
3) Perform some processing of assembler directives.
1) Assign address to all statements in the program.
2) Save the values assigned to all tables for use in pass 2.
3) Perform some processing of assembler directives.
Question 4 |
Mention the pass number for each of the following activities that occur in a two pass assembler
- (a) object code generation
(b) literals added literal table
(c) listing printed
(d) address resolution of local symbols
a-2, b-1, c-2, d-1 |
Question 4 Explanation:
Two pass assembler.
Pass 1:
→ Assign addresses to all statements.
→ Save the values assigned to all labels for use in pass 2.
→ Perform some processing of assembler directives.
Pass 2:
→ Assembler instructions by translating opcode and symbolic operands.
→ Generate data values defined by BYTE, WORD.
→ Perform processing of assembler directives not done in pass 1.
→ Write the object program and the assembly listing.
Pass 1:
→ Assign addresses to all statements.
→ Save the values assigned to all labels for use in pass 2.
→ Perform some processing of assembler directives.
Pass 2:
→ Assembler instructions by translating opcode and symbolic operands.
→ Generate data values defined by BYTE, WORD.
→ Perform processing of assembler directives not done in pass 1.
→ Write the object program and the assembly listing.
There are 4 questions to complete.