DescriptionQ713
Q713FWASIC interview problem
Insert a packed bit field
TechniquesBitsField mask
DifficultyMedium
TopicBit Manipulation
LanguageSystemVerilog
Requirements4 checkpoints
01
Problem
Replace bits [hi:lo] of a 32-bit word with the low bits of field while preserving all other bits.
Example input and output
Use this case to check your interpretationInput
x = 32'h0000_A55A, field = 4'h3, hi = 7, lo = 4Output
32'h0000_A53AExplanation
The nibble mask clears bits [7:4] before the new packed field is ORed into that position.
02
Requirements (4)
- Require indices that satisfy 0 <= lo <= hi <= 31.
- Create a mask covering hi through lo, inclusive.
- Clear the destination region before inserting the shifted field.
- Handle a full-width [31:0] field without shifting a 32-bit value by 32.