User's Manual

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S3C2450X RISC MICROPROCESSOR DMA CONTROLLER
9-7
3.2 EXAMPLES OF POSSIBLE CASES
3.2.1 Single service, Demand Mode, Single Transfer Size
The assertion of XnXDREQ is need for every unit transfer (Single service mode), the operation continues while
the XnXDREQ is asserted(Demand mode), and one pair of Read and Write(Single transfer size) is performed.
XnXDREQ
XnXDACK
XSCLK
XnXDREQ
XnXDACK
Double
synch
Read Write Read Write
Figure 9-4. Single service, Demand Mode, Single Transfer Size
Single service/Handshake Mode, Single Transfer Size
XnXDREQ
XnXDACK
XSCLK
Read Write
Read Write
2cycles
Double
synch
Figure 9-5. Single service, Handshake Mode, Single Transfer Size
Whole service/Handshake Mode, Single Transfer Size
XSCLK
XnXDREQ
XnXDACK
Read Write Read Write Read Write
2cycles 2cycles3 cycles
Double
synch
Figure 9-6. Whole service, Handshake Mode, Single Transfer Size