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Preliminary
S3C2451X RISC MICROPROCESSOR
DMA CONTROLLER
9-7
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
EXAMPLES OF POSSIBLE CASES
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
2cycles
3 cycles
Double
synch
Figure 9-6. Whole service, Handshake Mode, Single Transfer Size