Digital System Important Digital Electronics and Logic Design
Inherited attribute is a natural choice in Keeping track of variable declaration
YACC builds up LALR parsing table
In an absolute loading scheme which loader function is accomplished by assembler Re-allocation
A parser with the valid prefix property is advantageous because it
Limits the amount of erroneous output passed to the text phase
The action of parsing the source program into proper syntactic classes is called Lexical analysis
Relocating bits used by relocating loader are specified by Linker
What is the binary equivalent of the decimal number 368 is 101110000
AB+(A+B)’ is equivalent to A?B
A top down parser generates Left Most Derivation
Running time of a program depends on, The way the registers and addressing modes are used, The order in which computations are performed and The usage of machine id
A bottom up parser generates Right most derivation in reverse The digital logic family which has the lowest propagation delay time is ECL
Logic X-OR operation of (4ACO)H & (B53F)H results FFFF
12-bit 2’s complement of –73.75 is 10110110.0100
A grammar that produces more than one parse tree for some sentence is called Ambiguous
In order to implement a n variable switching function, a MUX must have 2n inputs
The absorption law in Boolean algebra say that x + x . y = x
Which of the following is the fastest logic ECL
The linker is required to create a load modul
A latch is constructed using two cross-coupled NAND gates
Pee hole optimization Constant folding
The optimization which avoids test at every iteration is
Loop unrolling Scissoring enables
The 2’s complement of the number 1101101 is 0010011
Advantage of panic mode of error recovery is that.....!
Quadruples is not an intermediate code form?
A multiplexer is a logic circuit that accepts many inputs and gives one output
Shift reduce parsers are Bottom up parser
A compiler that runs on one machine and produces code for a different machine is called Cross compilation
In a positive logic system, logic state 1 corresponds to Higher voltage level
Input to code generator Intermediate code
8-bit 1’s complement form of –77.25 is 10110010.1011
The Gray code for decimal number 6 is equivalent to 0101
The output of lexical analyzer is Set of tokens
Local and loop optimization in turn provide motivation for Data flow analysis
Advantage of synchronous sequential circuits over asynchronous ones is faster operation
The NAND gate output will be low if the two inputs are 11
LR stands for Left to right and right most derivation in reverse
In computers, subtraction is generally carried out by 2’s complement
Canonical LR is the most powerful parser
Scanner is used for grouping of characters into tokens (in a computer)
Lexical analysis or scanning is the process where the stream of characters making up the source program is read from left to right and grouped into tokens.
A binary digit is called a Bit
External subroutines can be accessed by transfer vector approach of linking
Macro-processors are Compiler
A combinational logic circuit which sends data coming from a single source to two or more separate destinations is Demultiplexer
