Datasheet

V850ES/JG3-H, V850ES/JH3-H CHAPTER 17 ASYNCHRONOUS SERIAL INTERFACE C (UARTC)
R01UH0042EJ0500 Rev.5.00 Page 756 of 1513
Aug 12, 2011
(4) Baud rate
The baud rate is obtained by the following equation.
Baud rate = [bps]
When using the internal clock, the equation will be as follows (when using the ASCKC0 pin as clock at
UARTC0, calculate using the above equation).
Baud rate = [bps]
Remark f
UCLK = Frequency of base clock selected by the UCnCTL1.UCnCKS3 to UCnCTL1.UCnCKS0 bits
f
XX: Main clock frequency
m = Value set using the UCnCTL1.UCnCKS3 to UCnCTL1.UCnCKS0 bits (m = 0 to 10)
k = Value set using the UCnCTL2.UCnBRS7 to UCnCTL2.UCnBRS0 bits (k = 4 to 255)
The baud rate error is obtained by the following equation.
Error (%) = − 1 × 100 [%]
= − 1 × 100 [%]
When using the internal clock, the equation will be as follows (when using the ASCKC0 pin input as the
clock for UARTC0, calculate the baud rate error using the above equation).
Error (%) = − 1 × 100 [%]
Cautions 1. The baud rate error during transmission must be within the error tolerance on the
receiving side.
2. The baud rate error during reception must satisfy the range indicated in (5) Allowable
baud rate range during reception.
f
UCLK
2 × k
Actual baud rate (baud rate with error)
Target baud rate (correct baud rate)
fXX
2
m+1
× k
fUCLK
2 × k × Target baud rate
f
XX
2
m+1
× k × Target baud rate