Datasheet

V850ES/JG3 CHAPTER 10 WATCH TIMER FUNCTIONS
R01UH0015EJ0300 Rev.3.00 Page 388 of 870
Sep 30, 2010
(2) Prescaler compare register 0 (PRSCM0)
The PRSCM0 register is an 8-bit compare register.
This register can be read or written in 8-bit units.
Reset sets this register to 00H.
PRSCM07 PRSCM0 PRSCM06 PRSCM05 PRSCM04 PRSCM03 PRSCM02 PRSCM01 PRSCM00
After reset: 00H R/W Address: FFFFF8B1H
Cautions 1. Do not rewrite the PRSCM0 register during watch timer operation.
2. Set the PRSCM0 register before setting the PRSM0.BGCE0 bit to 1.
3. Set the PRSM0 and PRSCM0 registers according to the main clock frequency that is used
so as to obtain an f
BRG frequency of 32.768 kHz.
The calculation for fBRG is shown below.
f
BRG = fBGCS/2N
Remark f
BGCS: Watch timer source clock set by the PRSM0 register
N: Set value of PRSCM0 register = 1 to 256
However, N = 256 only when PRSCM0 register is set to 00H.