Operation Of Dma Controller; Operation Procedure - NEC 78K0R/KE3 User Manual

16-bit single-chip microcontrollers

Table of Contents

14.4 Operation of DMA Controller

<1> The DMA controller is enabled to operate when DENn = 1. Before writing the other registers, be sure to set

DENn to 1. Use 80H to write with an 8-bit manipulation instruction.

<2> Set an SFR address, a RAM address, the number of times of transfer, and a transfer mode of DMA transfer

to the DSAn, DRAn, CBCn, and DMCn registers.

<3> The DMA controller waits for a DMA trigger when DSTn = 1. Use 81H to write with an 8-bit manipulation

instruction.

<4> When a software trigger (STGn) or a start source trigger specified by IFCn3 to IFCn0 is input, a DMA transfer

<5> Transfer is completed when the number of times of transfer set by the DBCn register reaches 0, and transfer

is automatically terminated by occurrence of an interrupt (INTDMAn).

<6> Stop the operation of the DMA controller by clearing DENn to 0 when the DMA controller is not used.

CHAPTER 14 DMA CONTROLLER

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