SH7785 Datasheet, PDF (752/1692 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

14. Direct Memory Access Controller (DMAC)
CLKOUT
Bus cycle
DREQ (Rising edge)
DRAK (High-active)
DACK (High-active)
CPU
1st acceptance
DMAC
2nd acceptance
CPU
: Non-sensitive period
Acceptance started
Accepted after one cycle of CLKOUT
at the first rising edge of the divided-up DACK
Figure 14.14 Example 2 of DREQ Input Detection in Cycle Steal Mode Edge Detection
(Word Transfer in 8-Bit Bus Width, Longword Transfer in 8/16-Bit Bus Width, 16/32-Byte
Transfer in 8/16/32/64-Bit Bus Width: DACK of DMA1 Transfer Divided)
CLKOUT
Bus cycle
Address
DREQ (Rising edge)
DRAK (High-active)
DACK (High-active)
CPU
1st acceptance
DMAC
2nd acceptance
CPU
: Non-sensitive period
Acceptance started
Accepted after one cycle of CLKOUT
at the rising edge of DACK
Figure 14.15 Example 3 of DREQ Input Detection in Cycle Steal Mode Edge Detection
(Word Transfer in 8-Bit Bus Width, Longword Transfer in 8/16-Bit Bus Width, or 16/32-
Byte Transfer in 8/16/32/64-Bit Bus Width: DACK of DMA1 Transfer Is Connected)
Rev.1.00 Jan. 10, 2008 Page 722 of 1658
REJ09B0261-0100