Register Read Clear Observation Mask Tool

Description

Parse nonnegative before and clearMask within the specified 1-128-bit width.

A register mask selects bits within a fixed width. Read-clear and write-one-to-clear semantics describe state transitions that differ from ordinary assignment.

Parse nonnegative before and clearMask within the specified 1-128-bit width.

When to use this tool

Use Register Read Clear Observation Mask when you need a deterministic fixed-width field or register-state calculation.

How to use the tool and how it works

Enter before, clearMask, width. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read observed, after. Use the output convention below.

Parse nonnegative before and clearMask within the specified 1-128-bit width. Return observed equal to before and after with masked bits cleared.^[1]

Input field	Meaning and units	Accepted input
before	Before	Required. Text; maximum UTF-16 length 8192. Integer syntax: optional + or - and 1-128 decimal digits; leading zeros accepted. Apply the sign restriction above.
clearMask	Clear Mask	Required. Text; maximum UTF-16 length 8192. Integer syntax: optional + or - and 1-128 decimal digits; leading zeros accepted. Apply the sign restriction above.
width	Width	Required. Safe integer; minimum 1; maximum 128.

Output field	Interpretation	Returned shape
observed	Observed	Required. Text; maximum UTF-16 length 8192.
after	After	Required. Text; maximum UTF-16 length 8192.

json

{
  "input": {
    "before": "15",
    "clearMask": "5",
    "width": 8
  },
  "output": {
    "observed": "15",
    "after": "10"
  }
}

Limitations and assumptions

No actual register is read; concurrency, side effects beyond the mask, and hardware access ordering are not modeled.
Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.

Alternative or Complementary methods

Use the device's access semantics and account for concurrent hardware changes before applying a register operation.

References

Calculation and input contract: microcontroller/register-read-clear-observation-mask — tool.io

Similar or alternative tools

Microcontroller: Register Write Clear Effect
Parse current, writtenOnes, and clearableMask as width-bounded unsigned decimal integers.
Microcontroller: Interrupt Pending Enabled Mask
Intersect pending and enabled masks for actionableMask.