SH7727 Datasheet, PDF (508/1109 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7700 Series

Section 14 Direct Memory Access Controller (DMAC)
CMCNT0 Count Timing
One of four peripheral clocks (Pφ/4, Pφ/8, Pφ/16, Pφ/64) which are divided from the clock (Pφ)
can be selected with the CKS1 and CKS0 bits in CMCSR0. Figure 14.28 shows the timing.
Peripheral clock
(Pφ)
CMT clock
CMCNT0 input
clock
CMCNT0
N-1
N
N+1
Figure 14.28 Count Timing
14.4.4 Compare-Match
Compare-Match Flag Set Timing
When the CMCOR0 register and the CMCNT0 counter match, a compare-match signal is
generated and the CMF bit in the CMCSR0 register is set to 1. The compare-match signal is
generated upon the final state of the match (timing at which the CMCNT0 counter value is
updated). Consequently, after the CMCOR0 register and the CMCNT0 counter match, a compare-
match signal will not be generated until a CMCNT0 counter input clock occurs. Figure 14.29
shows a timing of the CMF bit setting.
Rev. 5.00 Dec 12, 2005 page 436 of 1034
REJ09B0254-0500