Uart Clock Error Sign Tool

Description

Divide actualBaud minus targetBaud by positive targetBaud.

UART frames combine a start bit, data, optional parity, and stop duration. Baud rate and framing choices jointly determine time and overhead, while polarity and parity correctness are separate checks.

Divide actualBaud minus targetBaud by positive targetBaud.

When to use this tool

Use Uart Clock Error Sign when you need one UART timing, framing, or field calculation.

How to use the tool and how it works

Enter actualBaud, targetBaud, receiverToleranceFraction. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read relativeError, direction, withinSuppliedTolerance. Inspect withinSuppliedTolerance before interpreting the associated values.

Divide actualBaud minus targetBaud by positive targetBaud. Return its sign and compare the absolute fractional error inclusively with receiverToleranceFraction.^[1]

Input field	Meaning and units	Accepted input
actualBaud	Actual Baud	Required. Finite number; strictly above 0.
targetBaud	Target Baud	Required. Finite number; strictly above 0.
receiverToleranceFraction	Receiver Tolerance Fraction	Required. Finite number; minimum 0.

Output field	Interpretation	Returned shape
relativeError	Signed dimensionless error fraction; multiply by 100 only to display percent.	Required. Finite number.
direction	Direction	Required. Safe integer.
withinSuppliedTolerance	Within Supplied Tolerance	Required. Boolean.

json

{
  "input": {
    "actualBaud": 10100,
    "targetBaud": 10000,
    "receiverToleranceFraction": 0.02
  },
  "output": {
    "relativeError": 0.01,
    "direction": 1,
    "withinSuppliedTolerance": true
  }
}

Limitations and assumptions

A supplied tolerance is not a universal UART limit; combined transmitter/receiver errors and clock drift need separate analysis.
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

Confirm the device's supported frame format and clock budget, then inspect a measured serial waveform where needed.

References

Calculation and input contract: microcontroller/uart-clock-error-sign — tool.io

Similar or alternative tools

Uart Oversampling Divider Error
Calculate actualBaud = clock / (oversampling × divider), requiring positive clock and baud and positive integer divisors.
Watchdog Clock Tolerance Interval
For positive ticks and nominalHz, divide ticks by nominalHz × (1 + relativeTolerance) for minimumSeconds and by nominalHz × (1 - relativeTolerance) for maximumSeconds.