Register Field Decoder
Extract an unsigned 32-bit register field using exact integer bit operations and explicit field bounds.
Description
Register-field extraction isolates bits without interpreting their hardware meaning.
Register-field extraction isolates bits without interpreting their hardware meaning. The least-significant bit offset determines the shift before masking.1
Extract an unsigned 32-bit register field using exact integer bit operations and explicit field bounds.
When to use Register Field Decoder
Use this tool to extract an unsigned 32-bit register field using exact integer bit operations and explicit field bounds.
Prepare the single firmware record, sampled digital states or effective timing/register parameters requested. Confirm byte order, bit numbering, units and device-specific limits before interpreting the calculation.
How to use Register Field Decoder and understand its results
- Prepare the single firmware record, sampled digital states or effective timing/register parameters requested. Confirm byte order, bit numbering, units and device-specific limits before interpreting the calculation.
- Enter register, offset, width using the field table and calculation rules, then run the tool.
- Read value. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| register | Unsigned 32-bit register value. | integer; minimum: 0; maximum: 4294967295 | Required |
| offset | Least-significant bit offset. | integer; minimum: 0; maximum: 31 | Required |
| width | Field width in bits. | integer; minimum: 1; maximum: 32 | Required |
Enter an unsigned 32-bit register with integer offset and width. Reject fields extending beyond bit 31, perform BigInt shift/mask and return an unsigned numeric field.
value=(register>>offset) AND (2^width−1) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| value | Unsigned result. | integer; minimum: 0; maximum: 4294967295 |
{
"input": {
"register": 4294901760,
"offset": 4,
"width": 8
},
"output": {
"value": 0
}
}Limitations and assumptions
No device register map, signed-field interpretation or hardware read is performed.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Register Field Encoder: Replace an unsigned 32-bit register field using exact integer bit operations and explicit field bounds. For a complementary task, use CAN Bit Timing Calculator: Calculate nominal CAN bitrate and sample point from effective prescaler and segment lengths, including the one-quantum synchronization segment.
References
-
Register Field Decoder — tool.io
Similar or alternative tools
- Register Field Encoder
Replace an unsigned 32-bit register field using exact integer bit operations and explicit field bounds.
- CAN Bit Timing Calculator
Calculate nominal CAN bitrate and sample point from effective prescaler and segment lengths, including the one-quantum synchronization segment.