RX610 Group
18. Compare Match Timer (CMT)
R01UH0032EJ0120 Rev.1.20
Page 596 of 1006
Feb 20, 2013
18.5.4
Notes on Rewriting Compare Match Timer Control Register (CMCR)
When rewriting to the CMCR competes with generation of the compare match, writing to the CMCR is ignored.
Therefore, it is necessary to check if data is written correctly by reading the CMCR after writing to the CMCR. If the
data is not written correctly, once again the writing should be carried out to the CMCR. Because the read value of bit 7 in
CMCR is not defined, care should to be taken while comparing it with the written data.
18.5.5
Notes on Compare Match Timer Counter (CMCNT) and Compare Match
Constant Register (CMCOR)
Do not set the CMCNT and the CMCOR to the same value while the count operation of the CMCNT is stopped. If the
CMCNT and the CMCOR are set to the same value with the CMCNT count operation halted, the compare match occurs
irrespective of halted count operation. At this time, when the compare match interrupt enable bit (the CMIE bit in
CMCR) has been enabled (set to 1), the compare match interrupt occurs. Despite of disabling/enabling of the compare
match interrupt, if the compare match occurs due to matching of the value with the value of the CMCOR, the CMCNT is
automatically cleared to 0000h.