CHAPTER 10 SERIAL INTERFACE FUNCTION
User’s Manual U14492EJ3V0UD
441
(c) Baud rate
The baud rate is the value obtained according to the following formula.
Baud rate = [bps]
f
CLK
= Frequency [Hz] of base clock selected according to TPS3 to TPS0 bits of CKSR0 register
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.
[%]
100
1
rate)
baud
(normal
rate
baud
Desired
error)
with
rate
(baud
rate
baud
Actual
(%)
Error
×
−
=
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
CLK
) = 20 MHz = 20,000,000 Hz
Settings of MDL7 to MDL0 bits in BRGC0 register = 01000001B (k = 65)
Target baud rate = 153,600 bps
Baud rate = 20M/(2
×
65)
= 20000000/(2
×
65) = 153,846 [bps]
Error = (153846/153600
−
1)
×
100
= 0.160 [%]
f
CLK
2
×
k
Содержание V850E/IA1 mPD703116
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