SH7670 Datasheet, PDF (944/1292 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7670 Series

Section 21 Compare Match Timer (CMT)
21.4 Interrupts
21.4.1 Interrupt Sources and DMA Transfer Requests
The CMT has channels and each of them to which a different vector address is allocated has a
compare match interrupt. When both the compare match flag (CMF) and the interrupt enable bit
(CMIE) are set to 1, 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 controller
settings. For details, see section 6, Interrupt Controller (INTC).
Clear the CMF bit to 0 by the user exception handling routine. If this operation is not carried out,
another interrupt will be generated. The direct memory access controller (DMAC) can be set to be
activated when a compare match interrupt is requested. In this case, an interrupt is not issued to
the CPU. If the setting to activate the DMAC has not been made, an interrupt request is sent to the
CPU. The CMF bit is automatically cleared to 0 when data is transferred by the DMAC.
21.4.2 Timing of Compare Match Flag Setting
When CMCOR and CMCNT match, a compare match signal is generated at the last state in which
the values match (the timing when the CMCNT value is updated to H'0000) and the CMF bit in
CMCSR is set to 1. That is, after a match between CMCOR and CMCNT, the compare match
signal is not generated until the next CMCNT counter clock input. Figure 21.4 shows the timing of
CMF bit setting.
Rev. 1.00 Nov. 14, 2007 Page 918 of 1262
REJ09B0437-0100