Notes On Using 16-Bit Reload Timer - Fujitsu 8FX Hardware Manual

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.
376 FUJITSU SEMICONDUCTOR LIMITED
MB95630H Series
MN702-00009-2v0-E