Fujitsu FR81S User Manual
CHAPTER 8: DMA CONTROLLER (DMAC)
6. DMA Usage Examples
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : DMA CONTROLLER (DMAC)
FUJITSU SEMICONDUCTOR CONFIDENTIAL
46
This is a communication example via the multi-function serial interface that uses the DMA. In this example,
an interrupt of the multi-function serial interface is occupied by the DMA transfer request. Therefore, the
CPU polls the status registers to check for an error occurrence.
Figure 6-2 Communication Example via the Multi-function Serial Interface That Uses DMA
Multi-function serial interface
FIFO
UART
External device
CPU
DMAC
Settings (DMA transfer conditions)
Settings (protocol, etc.)
Settings (FIFO interrupt conditions)
Settings (DMA disable)
Settings (communication disable)
Settings (clear each item)
Settings (reset)
Settings (communication disable)
Settings (clear each item)
Settings (reset)
Check for existence of error
Check for existence of error
DMA requestby interrupt
Data transfer
Data
Data
DMA requestby interrupt
Data transfer
MB91520 Series
MN705-00010-1v0-E
345