DMA 是否可以用于CAN 和 SCI 的收发？

http://www.deyisupport.com/question_answer/microcontrollers/hercules/f/70/t/45136.aspx

http://www.deyisupport.com/question_answer/microcontrollers/hercules/f/70/t/62677.aspx

SCI

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经测试能够在RM49L952上运行，仅供参考：

sciInit();
load_data();
/* - DMA Configuration */

/* Enable DMA */
dmaEnable();

/* assigning dma request: channel-0 with request line - 1 - TX*/
/* DMA Request 29 is for LIN ( SCI2) Transmit */
/* Refer Data sheet - Default DMA Request Map section */
dmaReqAssign(DMA_CH0,29);

/* - configuring dma control packets */
g_dmaCTRLPKT.SADD = (uint32)(&TX_DATA); /* source address */
g_dmaCTRLPKT.DADD = (uint32)(&scilinREG->TD); /* destination address */
g_dmaCTRLPKT.CHCTRL = 0; /* channel control */
g_dmaCTRLPKT.FRCNT = D_SIZE; /* frame count */
g_dmaCTRLPKT.ELCNT = 1; /* element count */
g_dmaCTRLPKT.ELDOFFSET = 0; /* element destination offset - is required? */
g_dmaCTRLPKT.ELSOFFSET = 0; /* element source offset - is required? */
g_dmaCTRLPKT.FRDOFFSET = 0; /* frame detination offset - is required? */
g_dmaCTRLPKT.FRSOFFSET = 0; /* frame source offset - is required? */
g_dmaCTRLPKT.PORTASGN = 4; /* port b */
g_dmaCTRLPKT.RDSIZE = ACCESS_8_BIT; /* read size */
g_dmaCTRLPKT.WRSIZE = ACCESS_8_BIT; /* write size */
g_dmaCTRLPKT.TTYPE = FRAME_TRANSFER ; /* transfer type */
g_dmaCTRLPKT.ADDMODERD = ADDR_INC1; /* address mode read */
g_dmaCTRLPKT.ADDMODEWR = ADDR_FIXED; /* address mode write */
g_dmaCTRLPKT.AUTOINIT = AUTOINIT_OFF; /* autoinit (loop) */
dmaSetCtrlPacket(DMA_CH0,g_dmaCTRLPKT);
/* - setting dma control packets for transmit */
dmaSetCtrlPacket(DMA_CH0,g_dmaCTRLPKT);

/* - setting the dma channel to trigger on h/w request */
dmaSetChEnable(DMA_CH0, DMA_HW);

/* Enable TX DMA */
scilinREG->SETINT = (1 << 16);