R01UH0823EJ0100 Rev.1.00
Page 725 of 1823
Jul 31, 2019
RX23W Group
25. 16-Bit Timer Pulse Unit (TPUa)
25.9.17
Continuous Output of Underflow Pulse Interrupt Signal
If two external clock signals' same direction edges to be phase counted are generated within two PCLK cycles in phase
counting mode 1, with TGR being 0000h, and compare match set as the counter clear source, the TCNT remains 0000h
and is not updated, and a compare-match pulse interrupt signal and an underflow interrupt signal are output continuously
to form a flat signal level.
When a pulse interrupt signal is used, the interrupt controller cannot detect the second and subsequent interrupts.
shows an operation timing when the underflow pulse interrupt signal is output continuously.
Figure 25.55
Continuous Output of Underflow Pulse Interrupt Signal
PCLK
Less than 2 PCLK cycles Less than 2 PCLK cycles
TCLKA
TCLKB
Count-down signal
Compare match
(counter clear) signal
Underflow signal
0000h
0000h
TCNT
TGRA
Compare-match pulse
interrupt signal
Underflow pulse
interrupt signal