Fujitsu F2MC-16LX Hardware Manual page 336

CHAPTER 16 16-BIT RELOAD TIMER
I 16-Bit reload register (TMRLR)
Regardless of the 16-bit reload timer operation, set this register to the initial counter value while
counter operation is disabled (TMCSR: CNTE=0). When the counter is started by enabling
counter operation (TMCSR: CNTE=1), the count-down will start from the value that was written
to this register. The value set in this register is reloaded in reload mode if an underflow occurs,
and count-down continues. In one-shot mode, the counter stops at FFFF
occurs.
Note:
Write to this register only in counter stop mode (TMCSR: CNTE = 0), and always by using a
word transfer instruction (such as "MOVW A 003AH").
The 16-bit reload register (TMRLR) is functionally a write-only register; however, it is
allocated at the same address as the read-only 16-bit timer register (TMR). Thus, the valid
returned value in read operations is the value of the TMR value. Read-modify-write (RMW)
instructions (such as the INC or DEC instructions) cannot be used.
320
if an underflow
H