NEC 78K0 Series User Manual page 379

(a) Baud rate
The baud rate can be calculated by the following expression.
f
XCLK6
• Baud rate =
[bps]
2 × k
f : Frequency of base clock selected by TPS63 to TPS60 bits of CKSR6 register
XCLK6
k: Value set by MDL67 to MDL60 bits of BRGC6 register (k = 8, 9, 10, ..., 255)
(b) Error of baud rate
The baud rate error can be calculated by the following expression.
Actual baud rate (baud rate with error)
• Error (%) =
Desired baud rate (correct baud rate)
Cautions 1. Keep the baud rate error during transmission to within the permissible error range at
the reception destination.
2. Make sure that the baud rate error during reception satisfies the range shown in (4)
Permissible baud rate range during reception.
Example: Frequency of base clock = 10 MHz = 10,000,000 Hz
Set value of MDL67 to MDL60 bits of BRGC6 register = 00100001B (k = 33)
Target baud rate = 153600 bps
Baud rate = 10 M/(2 × 33)
Error = (151515/153600 − 1) × 100
= −1.357 [%]
CHAPTER 15 SERIAL INTERFACE UART6
= 10000000/(2 × 33) = 151,515 [bps]
Preliminary User's Manual U17260EJ3V1UD
− 1 × 100 [%]
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