Fujitsu FR60 Hardware Manual page 280

CHAPTER 6 8/16-bit Up/Down Counters/Timer and U-Timers
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When the compare clear function is enabled
The compare clear function can be used in all modes other than timer mode. When the compare function is
started, if the value of RCR and the value of UDCR match, CMPF is set and an interrupt request is
generated. When the compare clear function is started, the UDCR is cleared with the timing of the next up
count clock. (The UDCR is not cleared when counting down is performed.)
In a mode in which up counting is not performed, starting this function is invalid.
Figure 6.1-6 shows an overview of compare function operation.
(0FFFF )
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0FF
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RCR
00
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■ Up/Down Counting with an Arbitrary Width when the Reload and Compare Functions
are Started
When the reload/compare function is started, counting up or down can be performed with an arbitrary
width.
The reload function is started at an underflow and transfers the value of the RCR to the UDCR. When the
values of RCR and UDCR match, the compare function clears the UDCR. By using these functions,
counting up or down is performed for values between 0000
Figure 6.1-7
simultaneously.
262
Figure 6.1-6 Overview of the Compare Function Operation
Compare match
Counter is cleared,
interrupt is generated.
shows an overview of operation when the reload and compare functions are started
Compare match
Counter is cleared,
interrupt is generated.
and the value of the RCR.
H