Fujitsu 8FX

MB95630H Series
376 FUJITSU SEMICONDUCTOR LIMITED MN702-00009-2v0-E
CHAPTER 20 16-BIT RELOAD TIMER
20.8 Notes on Using 16-bit Reload Timer
20.8 Notes on Using 16-bit Reload Timer
This section provides notes on using the 16-bit reload timer.
■ Notes on Using 16-bit Reload Timer
● Notes on setting the program
• The 16-bit reload timer timer register ch. n (TMRHn/TMRLn) can read the count value
even during the counting operation of the 16-bit reload timer. To read this register, use a
word transfer instruction, or read the upper byte of this register first and then its lower byte.
• A value can be written to the 16-bit reload timer reload register ch. n (TMRLRHn/
TMRLRLn) even during the counting operation of the 16-bit reload timer. To write a value
to this register, use a word transfer instruction, or write the upper byte of this register first
and then its lower byte.
● Notes on interrupts
With the underflow interrupt request enabled (TMCSRLn:INTE = 1), if the underflow interrupt
request flag bit (UF) in the 16-bit reload timer control status register (lower) ch. n (TMCSRLn)
is set to "1", the CPU cannot wake up from the interrupt service routine. Therefore, always
clear the UF bit in the interrupt service routine.