Datasheet

V850ES/JG3-H, V850ES/JH3-H CHAPTER 12 REAL-TIME COUNTER
R01UH0042EJ0500 Rev.5.00 Page 650 of 1513
Aug 12, 2011
(13) Watch error correction register (RC1SUBU)
The RC1SUBU register (8-bit) can be used to correct the watch with high accuracy when the watch is early or late,
by changing the value (reference value: 7FFFH) overflowing from the sub-count register (RSUBC) to the second
counter register.
This register can be read or written in 8-bit or 1-bit units.
Reset sets this register to 00H.
Remarks 1. The RC1SUBU register can be rewritten only when the real-time counter is set to its initial values.
Be sure to see 12.4.1 Initial settings.
2. See 12.4.9 Watch error correction example of real-time counter for details of watch error
correction.
DEV
Corrects watch errors when RC1SEC (second counter) is at 00, 20, or
40 seconds (every 20 seconds).
Corrects watch errors when RC1SEC (second counter) is at 00 seconds
(every 60 seconds).
DEV
0
1
Setting of watch error correction timing
RC1SUBU F6 F5 F4 F3
F2
F1 F0
654321
Increments the RC1SUBC count value by the value set using the F5 to
F0 bits (positive correction).
Expression for calculating increment value:
(Setting value of F5 to F0 bits − 1) × 2
Decrements the RC1SUBC count value by the value set using the F5 to
F0 bits (negative correction).
Expression for calculating decrement value:
(Inverted value of setting value of F5 to F0 bits + 1) × 2
F6
0
1
Setting of watch error correction value
If the F6 to F0 bit values are {1/0, 0, 0, 0, 0, 0, 1/0}, watch error correction is not
performed.
07
After reset: 00H R/W Address: FFFFFAD9H