Panasonic MN103001G/F01K - Manual (Page 250)

8-bit Timers
10-30
When "cascaded with timer 0" is set, operation is as shown in Fig. 10-6-7. (IOCLK is selected as the clock source
for timer 0.)
If TM1BC does not equal x'00, then when TM0BC underflows, the value in TM0BC is x'FF and the value in
TM1BC is decremented by one.
If TM1BC does equal x'00, then when TM0BC underflows, the values that are set in TM0BR and TM1BR are
loaded into TM0BC and TM1BC, respectively, and a timer 1 interrupt request is generated.
TM0BC value
Interrupt request
signal (TM1IRQ)
TM1BC value
x'00 x'01
IOCLK
x'00 x'01
TM0BR value TM0BR value-1
x'00 x'01
Interrupt request
signal (TM0IRQ)
x'00 x'01
TM1BR value
x'FE x'FF x'FF
TM1BR value - 1
Fig. 10-6-7 Operation of Timers 0 and 1 (2)