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6 precautions when using 16-bit reload timer, Precautions when using 16-bit reload timer – FUJITSU F2MCTM-16LX User Manual

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CHAPTER 14 16-BIT RELOAD TIMER

14.6

Precautions when Using 16-bit Reload Timer

This section explains the precautions when using the 16-bit reload timer.

Precautions when Using 16-bit Reload Timer

Precautions when setting by program

Set the 16-bit reload register (TMRLR) after disabling the timer operation (TMCSR:CNTE = 0)

The 16-bit timer register (TMR) can be read during the TMR count operation. However, always use the

word instruction.

Change the CSL1 and CSL0 bits in the TMCSR after disabling the timer operation (TMCSR:CNTE = 0)

Precautions on interrupt

When the UF bit in the TMCSR is set to 1 and the underflow interrupt output is enabled (TMCSR:INTE

= 1), it is impossible to return from interrupt processing. Always clear the UF bit. However, when the

EI

2

OS is used, the UF bit is cleared automatically.

When using the EI

2

OS in the 16-bit reload timer, it is necessary to disable the interrupt of the 16-bit

reload timer that shares the interrupt control register (ICR).