Renesas M16C Laptop User Manual


 
Rev.1.10 Jul 01, 2005 page 290 of 318
REJ09B0124-0110
M16C/6N Group (M16C/6NK, M16C/6NM) 22. Usage Precaution
Under development
This document is under development and its contents are subject to change.
22.9 Timers
22.9.1 Timer A
22.9.1.1 Timer A (Timer Mode)
The timer remains idle after reset. Set the mode, count source, counter value, etc. using the TAiMR (i =
0 to 4) register and the TAi register before setting the TAiS bit in the TABSR register to 1 (count starts).
Always make sure the TAiMR register is modified while the TAiS bit remains 0 (count stops) regardless
whether after reset or not.
While counting is in progress, the counter value can be read out at any time by reading the TAi register.
However, if the counter is read at the same time it is reloaded, the value FFFFh is read. Also, if the
counter is read before it starts counting after a value is set in the TAi register while not counting, the set
value is read.
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If a low-level signal is applied to the NMI pin when the IVPCR1 bit in the TB2SC register = 1 (three-
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phase output forcible cutoff by input on NMI pin enabled), the TA1OUT, TA2OUT and TA4OUT pins go
to a high-impedance state.