Renesas 7700 FAMILY User Manual page 142

[Precautions when operating in timer mode]
By reading the timer Bi register, the counter value can be read out at any timing while counting is in
progress. However, if the timer Bi register is read at the reload timing shown in Figure 6.3.4, the value
"FFFF " is read out. When reading the timer Bi register after setting a value to the register while counting
16
is not in progress and before the counter starts counting, the set value can be read out correctly.
Fig. 6.3.4 Reading timer Bi register
Counter value
2
(Hex.)
Read value
2
(Hex.)
n = Reload register's contents
7751 Group User's Manual
Reload
1 0 n n – 1
1 0 FFFF n – 1
Time
TIMER B
6.3 Timer mode
6–13