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10.4 TIO (Input/Output-Related 16-Bit Timer)
MULTIJUNCTION TIMERS
10
32192/32195/32196 Group Hardware Manual
Rev.1.10 REJ09B0123-0110 Apr.06.07
10.4.10 Operation in TIO Noise Processing Input Mode
In noise processing input mode, the timer is used to detect that the input signal remained in the same state for
over a predetermined time.
In noise processing input mode, a "H" or "L" level on external input activates the counter and if the input signal
remains in the same state for over a predetermined time before the counter underflows, the counter generates
an interrupt request before stopping. If the valid-level signal being applied turns to an invalid level before the
counter underflows, the counter temporarily stops counting and at the next cycle after a valid-level signal is
entered again, the counter is reloaded with the value that "reload register -1" and restarts counting. The effec-
tive count width is "reload 0 register set value + 1."
The timer stops at the same time the counter underflows or count is disabled by writing to the enable bit.
Furthermore, it is possible to generate an interrupt request and a DMA transfer request (for only the TIO8 and
TIO9) upon underflow of the counter.
Figure 10.4.8 Typical Operation in Noise Processing Input Mode
H'FFFF
H'0000
H'A000
DMA transfer request (Note 1)
Note 1: Only TIO8 and TIO9 can be generated.
Note 2: The value that "reload register - 1" is reloaded.
Note: This diagram does not show detailed timing information.
DMA transfer request
due to underflow
Reload 0 register
External input
(noise processing)
Effective signal
width
Invalid
Disabled by underflow
Count clock
Counter
Enabled
(by writing to
the enable bit)
TIO interrupt request
Enable bit
Invalid
TIO interrupt request
due to underflow
Undefined
value
(Note 2)