Datasheet

V850ES/JG3 CHAPTER 8 16-BIT TIMER/EVENT COUNTER Q (TMQ)
R01UH0015EJ0300 Rev.3.00 Page 302 of 870
Sep 30, 2010
(c) Notes on rewriting TQ0CCR0 register
To change the value of the TQ0CCR0 register to a smaller value, stop counting once and then change the set
value.
If the value of the TQ0CCR0 register is rewritten to a smaller value during counting, the 16-bit counter may
overflow.
FFFFH
16-bit counter
0000H
TQ0CE bit
TQ0CCR0 register
TQ0OL0 bit
TOQ00 pin output
INTTQ0CC0 signal
D 1 D 2
D 1 D 1
D 2 D 2 D 2
L
Interval time (1) Interval time (NG) Interval
time (2)
Remark Interval time (1): (D
1 + 1) × Count clock cycle
Interval time (NG): (10000H + D
2 + 1) × Count clock cycle
Interval time (2): (D
2 + 1) × Count clock cycle
If the value of the TQ0CCR0 register is changed from D1 to D2 while the count value is greater than D2 but less
than D
1, the count value is transferred to the CCR0 buffer register as soon as the TQ0CCR0 register has been
rewritten. Consequently, the value of the 16-bit counter that is compared is D
2.
Because the count value has already exceeded D2, however, the 16-bit counter counts up to FFFFH, overflows,
and then counts up again from 0000H. When the count value matches D
2, the INTTQ0CC0 signal is generated
and the output of the TOQ00 pin is inverted.
Therefore, the INTTQ0CC0 signal may not be generated at the interval time “(D
1 + 1) × Count clock cycle” or
“(D
2 + 1) × Count clock cycle” originally expected, but may be generated at an interval of “(10000H + D2 + 1) ×
Count clock period”.