Fletcher16 Component Joiner
Split or join packed Fletcher-16 8-bit checksum components by numeric lanes; does not recompute or verify checksum residues.
Description
Split or join packed Fletcher-16 8-bit checksum components by numeric lanes; does not recompute or verify checksum residues.
A 16-bit Fletcher-style stored value can be split into low and high byte components independently of its running-sum calculation.
When to use this tool
Split or join packed Fletcher-16 8-bit checksum components by numeric lanes; does not recompute or verify checksum residues.
- Prepare the supplied low, high fields for this operation.
- Compare the complete example with the representation used by your own input before carrying the result into another step.
How to use the tool and how it works
- Enter low, high. Use the exact text syntax, units and index conventions explained below.
- Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
- Read result.value. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Require low and high from 0 to 255. Return high times 256 plus low.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| low | low. | Integer from 0 to 255 inclusive |
| high | high. | Integer from 0 to 255 inclusive |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.value | The value value under the stated formula or text convention. |
{
"input": {
"low": 1,
"high": 2
},
"output": {
"result": {
"value": 513
}
}
}Limitations and assumptions
- No Fletcher recurrence or modular-sum validity is checked. These are component bytes rather than a payload checksum computation.
- All declared input fields are required and unexpected top-level fields are rejected. Numbers must be finite; lists are limited to 128 entries and ordinary text fields to 8,192 UTF-16 code units, with tighter limits where stated.
- JSON text inputs must parse within bounded nesting and size limits. Numeric outputs outside the safe finite range are rejected; large exact integer results use decimal strings. Indexes and half-open spans are zero-based unless a rank is explicitly described as one-based.
Alternative or Complementary methods
Use the complete specified checksum algorithm and independent test vectors when verifying a payload. Field packing, parameter shape and arithmetic agreement are separate checks; none supplies cryptographic authenticity.
References
Similar or alternative tools
- Adler32 Component Joiner
Split or join packed Adler-32 16-bit checksum components by numeric lanes; does not recompute or verify checksum residues.
- Fletcher16 Component Splitter
Split or join packed Fletcher-16 8-bit checksum components by numeric lanes; does not recompute or verify checksum residues.