Datasheet

V850ES/JG3-H, V850ES/JH3-H CHAPTER 18 3-WIRE VARIABLE-LENGTH SERIAL I/O (CSIF)
R01UH0042EJ0500 Rev.5.00 Page 812 of 1513
Aug 12, 2011
(2) Prescaler compare registers 1 to 3 (PRSCM1 to PRSCM3)
The PRSCM1 to PRSCM3 registers are 8-bit compare registers.
These registers can be read or written in 8-bit units.
Reset sets these registers to 00H.
PRSCMm7 PRSCMm PRSCMm6 PRSCMm5 PRSCMm4 PRSCMm3 PRSCMm2 PRSCMm1 PRSCMm0
After reset: 00H R/W Address: PRSCM1 FFFFF321H, PRSCM2 FFFFF325H,
PRSCM3 FFFFF329H
Cautions 1. Do not rewrite the PRSCMm register during operation.
2. Set the PRSCMm register before setting the PRSMm.BGCEm bit to 1.
18.8.1 Baud rate generation
The transmission/reception clock is generated by dividing the main clock. The baud rate generated from the main clock
is obtained by the following equation.
f
BRGm =
Caution Set f
BRGm to 8 MHz, (CSIF0 to CSIF2 and CSIF4), 12 MHz (CSIF3), or lower.
Remark f
BRGm: BRGm count clock
fXX: Main clock oscillation frequency
k: PRSMm register setting value = 0 to 3
N: PRSCMm register setting value = 1 to 256
However, N = 256 only when the PRSCMm register is set to 00H.
m = 1 to 3
f
XX
2
k+1
× N