Fujitsu MB90335 Series Hardware Manual page 349

CHAPTER 14 16-BIT RELOAD TIMER
14.2 Registers of 16-bit Reload Timer
■ 16-bit Reload Register 0 (TMRLR0)
Set the initial counter value to the register TMRLR0 in the status the counter operation is inhibited (CNTE
= 0 for TMCSR0) regardless of the 16-bit reload timer operation. When the counter operation is permitted
(CNTE = 1 for TMCSR0) and the counter is started, the count down is started from the value written in the
registers TMRLR0. Values set in the register TMRLR0 are reloaded to the counter to continue the count
down at the underflow occurrence in the reload mode. In the one-shot mode, the counter stops at FFFF
when an underflow occurs.
Note:
Write the TMRLR0 register in the status the counter stops (CNTE = 0 for TMCSR0).
In addition, always use the word transfer instruction (MOVW A 003AH, etc.) when writing.
The 16-bit timer register (TMRLR0) has a write-only function despite its location at the same address
as the read-only 16-bit reload register (TMR0). Therefore, since the read value is the TMR0 value,
instructions such as INC, DEC, etc. cannot be used to perform the read-modify-write (RMW)
operations.
328 FUJITSU MICROELECTRONICS LIMITED
MB90335 Series
CM44-10137-6E
H