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8051 Baud Rate Calculator

This utility program calculates baud rates for 8051-compatible serial ports operating in Mode 1 using:

  • Timer 1 Mode 2 with SMOD = 0.
    Reload values calculated for TH1.
  • Timer 1 Mode 2 with SMOD = 1.
    Reload values are calculated for TH1.
  • Timer 2 (using the internal clock).
    Reload values are calculated for RCAP2.

You may specify non-standard clock divisors for Timer 1 and Timer 2.

Standard baud rates are used unless you enter a specific baud rate.

A list of standard oscillator frequencies and a description of typical uses for each is available from Vectron.

Enter Oscillator and Clock Information Below
Crystal Frequency: MHz
Serial Clock Divisor:
(Default: Timer 1 = 12, Timer 2 = 32)

* For best results, choose baud rates that are accurate to +/-1% or better.

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