
R8C/14 Group, R8C/15 Group 13. Timers
Rev.2.10 Jan 19, 2006 Page 88 of 253
REJ09B0164-0210
13.1.2 Pulse Output Mode
Pulse output mode is mode to count the count source internally generated and outputs the pulse
which inverts the polarity from the CNTR0 pin each time the timer underflows (See Table 13.3
Specification of Pulse Output Mode). Figure 13.5 shows TXMR Register in Pulse Output Mode.
NOTES:
1. The level of the output pulse becomes the level when the pulse output starts when the TX register is
written to.
Table 13.3 Specification of Pulse Output Mode
Item Specification
Count Source f1, f2, f8, fRING
Count Operation • Decrement
• When the timer underflows, the contents in the reload register is reloaded and
the count is inherited
Divide Ratio 1/(n+1)(m+1) n: setting value of PREX register, m: setting value of TX register
Count Start Condition Write “1” (count starts) to the TXS bit in the TXMR register
Count Stop Condition Write “0” (count stops) to the TXS bit in the TXMR register
Interrupt Request
Generation Timing
When Timer X underflows [Timer X interrupt]
INT10
/CNTR00 Pin
Function
Pulse output
CNTR0
Pin Function
Programmable I/O port or inverted output of CNTR0
Read from timer
The count value can be read by reading the TX and PREX registers.
Write to Timer • When writing to the TX and PREX registers while the count stops, the value is
written to both the reload register and counter.
• When writing to the TX and PREX registers during the count, the value is
written to each reload register of the TX and PREX registers at the following
count source input and the data is transferred to the counter at the second
count source input and the count re-starts at the third count source input.
Select Function
•INT1
/CNTR0 signal polarity switch function
The R0EDG bit can select the polarity level when the pulse output starts
(1)
• Inverted pulse output function
The pulse which inverts the polarity of the CNTR0 output can be output from
the CNTR0
pin (selected by TXOCNT bit)
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