NEC UPD703116 User Manual page 437

(c) Baud rate
The baud rate is the value obtained according to the following formula.
f = Frequency [Hz] of base clock selected according to TPS3 to TPS0 bits of CKSR0 register
CLK
k = Value set according to MDL7 to MDL0 bits of BRGC0 register (k = 8, 9, 10, ..., 255)
(d) Baud rate error
The baud rate error is obtained according to the following formula.
Actual baud rate (baud rate with error)
Error (%) =
Target baud rate (normal baud rate)
Cautions 1. Make sure that the baud rate error during transmission does not exceed the allowable
error of the reception destination.
2. Make sure that the baud rate error during reception is within the allowable baud rate
range during reception, which is described in (4) Allowable baud rate range during
reception.
Example: Base clock frequency (f
Settings of MDL7 to MDL0 bits in BRGC0 register = 01000001B (k = 65)
Target baud rate = 153,600 bps
Baud rate = 20M/(2 × 65)
Error = (153846/153600 − 1) × 100
= 0.160 [%]
CHAPTER 10 SERIAL INTERFACE FUNCTION
Baud rate =
) = 20 MHz = 20,000,000 Hz
CLK
= 20000000/(2 × 65) = 153,846 [bps]
User's Manual U14492EJ5V0UD
f
CLK
[bps]
2 × k
−1 × 100 [%]
437