RX610 Group
18. Compare Match Timer (CMT)
R01UH0032EJ0120 Rev.1.20
Page 594 of 1006
Feb 20, 2013
18.4
Interrupts
18.4.1
Interrupt Sources
The CMT has channels and each of them to which a different vector address is allocated has a compare match interrupt
(CMIm) (m = 0 to 3). When a compare match interrupt occurs, the corresponding interrupt request is output.
When the interrupt is used to activate a CPU interrupt, the priority of channels can be changed by the interrupt control
unit settings. For details, see section 10, Interrupt Control Unit (ICU).
Table 18.3 CMT Interrupt Sources
Name
Interrupt Sources
Interrupt
Status Flag
DTC
Activation
DMAC
Activation
CMI0
Compare match between CMT0.CMCNT and CMT0.CMCOR
IR028.IR
Possible
Possible
CMI1
Compare match between CMT1.CMCNT and CMT1.CMCOR
IR029.IR
Possible
Possible
CMI2
Compare match between CMT2.CMCNT and CMT2.CMCOR
IR030.IR
Possible
Possible
CMI3
Compare match between CMT3.CMCNT and CMT3.CMCOR
IR031.IR
Possible
Possible
18.4.2
Timing of Compare Match Interrupt Generation
When CMCNT and CMCOR match, a compare match interrupt (CMIm) (m = 0 to 3) is generated.
A compare match signal is generated at the last state in which the values match (the timing when the CMCNT counter
updates the matched count value). That is, after a match between CMCOR and CMCNT, the compare match signal is not
generated until the next CMCNT counter clock input.
Figure 18.4 shows the timing of interrupt flag setting to 1.
PCLK
CMCNT input clock
CMCNT
CMCOR
Interrupt flag
*
(IRi.IR of ICU)
N
N
0
Compare match signal
Note:
*
For the corresponding interrupt vector numbers, see section 10,
Interrupt Control Unit (ICU).
(i = 028 to 031)
Figure 18.4 Timing of Compare Match Interrupt Flag Setting to 1