英文:
Send data through SPI with DMA
问题
I need to send data as fast as possible from an Arduino DUE to an external DAC. To do so, I use DMA & SPI, and I want DMA to fetch data from memory and send it to SPI, which will relay it via its Master Output Slave Input. So far, I did a DMA transfer from one variable to another, and it worked perfectly. I'm using the same code but changing the address to SPI_TDR (Transmit Data Register), unfortunately, it's not working. I guess the address is not correct, but if so, what should I do?
Here is my code:
#include <dmac.h>
#include <SPI.h>
#define DMA_CH 0 // DMA Channel number
#define DMA_BUF_SIZE 32 // DMA memory size
uint32_t g_dma_buf2[DMA_BUF_SIZE];
void setup() {
Serial.begin(9600);
SPI.begin();
SPI0->SPI_WPMR = 0x53504900; // Protection key
SPI0->SPI_IDR = 0x0000070F; // Disable interrupts
SPI0->SPI_MR = SPI_MR_MSTR | SPI_MR_PS; // SPI master
}
void loop() {
Serial.println("+++++");
pmc_enable_periph_clk(ID_DMAC);
uint32_t i;
uint32_t cfg;
dma_transfer_descriptor_t desc;
for (i = 0; i < DMA_BUF_SIZE; i++) {
g_dma_buf2[i] = i;
Serial.print(g_dma_buf2[i]);
}
Serial.println();
dmac_init(DMAC);
dmac_set_priority_mode(DMAC, DMAC_PRIORITY_ROUND_ROBIN);
dmac_enable(DMAC);
cfg = DMAC_CFG_SOD_ENABLE | DMAC_CFG_AHB_PROT(1) | DMAC_CFG_FIFOCFG_ALAP_CFG; // CFG register config
dmac_channel_set_configuration(DMAC, DMA_CH, cfg);
desc.ul_source_addr = (uint32_t)g_dma_buf2;
desc.ul_destination_addr = SPI0->SPI_TDR;
desc.ul_ctrlA = DMAC_CTRLA_BTSIZE(DMA_BUF_SIZE) | DMAC_CTRLA_SRC_WIDTH_WORD | DMAC_CTRLA_DST_WIDTH_WORD;
desc.ul_ctrlB = DMAC_CTRLB_SRC_DSCR_FETCH_DISABLE | DMAC_CTRLB_DST_DSCR_FETCH_DISABLE | DMAC_CTRLB_FC_MEM2MEM_DMA_FC | DMAC_CTRLB_SRC_INCR_INCREMENTING | DMAC_CTRLB_DST_INCR_FIXED;
desc.ul_descriptor_addr = 0;
SPI_Enable(SPI0);
dmac_channel_multi_buf_transfer_init(DMAC, DMA_CH, &desc);
dmac_channel_enable(DMAC, DMA_CH);
Serial.println("*****");
while (!dmac_channel_is_transfer_done(DMAC, DMA_CH)) { Serial.print('X'); }
Serial.print("SR : "); Serial.println(SPI0->SPI_SR, HEX);
Serial.print("TDR : "); Serial.println(SPI0->SPI_TDR, HEX);
Serial.print("PSR : "); Serial.println(PIOA->PIO_PSR, HEX); // PIO_SODR
Serial.print("OSR : "); Serial.println(PIOA->PIO_OSR, HEX);
Serial.println(DMAC->DMAC_CH_NUM[0].DMAC_SADDR , HEX);
Serial.println(DMAC->DMAC_CH_NUM[0].DMAC_DADDR, HEX);
Serial.println("-----");
}
I mainly use this example: Microchip DMA Controller Application Note.
And here is the datasheet of the microcontroller: Microchip Cortex-M3 Microcontroller Datasheet.
You can see at the bottom of my code several prints, and from them, I had many ideas: does the PIO block the data? Could the address PIO_PA26A_SPI0_MOSI work? Could the SPI block the data because conditions are not met?
Any idea is welcomed; I've been working on this for some time now.
Edit: SPI is not a necessity; the idea is to send data without a length limit (unlike UART). I'm considering using SSC.
英文:
I need to send data as fast as possible from an Arduino DUE to an extern DAC. To do so I use DMA & SPI and I want DMA to fetch data from the memory and send it to the SPI which will just relay it via its Master Output Slave input.
So far I did a DMA transfer from a variable to another, woked perfectly. I'm using the same code but change the address as SPI_TDR (Transmit Data Register), unfortunatly it's not working. I guess the address is not good but if so what should I do ?
Here is my code :
#include <dmac.h>
#include <SPI.h>
#define DMA_CH 0 //N° Canal du DMA
#define DMA_BUF_SIZE 32 //Taille mémoire DMA
uint32_t g_dma_buf2[DMA_BUF_SIZE];
void setup() {
Serial.begin(9600);
SPI.begin();
SPI0->SPI_WPMR = 0x53504900; //Protection key
SPI0->SPI_IDR = 0x0000070F; //Desactivation interrupts
SPI0->SPI_MR = SPI_MR_MSTR | SPI_MR_PS; //SPI master
}
void loop() {
Serial.println("+++++");
pmc_enable_periph_clk(ID_DMAC);
uint32_t i;
uint32_t cfg;
dma_transfer_descriptor_t desc;
for (i = 0; i < DMA_BUF_SIZE; i++) {
g_dma_buf2[i] = i;
Serial.print(g_dma_buf2[i]);
}
Serial.println();
dmac_init(DMAC);
dmac_set_priority_mode(DMAC, DMAC_PRIORITY_ROUND_ROBIN);
dmac_enable(DMAC);
cfg = DMAC_CFG_SOD_ENABLE | DMAC_CFG_AHB_PROT(1) | DMAC_CFG_FIFOCFG_ALAP_CFG; //Config registre CFG
dmac_channel_set_configuration(DMAC, DMA_CH, cfg);
desc.ul_source_addr = (uint32_t)g_dma_buf2;
desc.ul_destination_addr = SPI0->SPI_TDR;
desc.ul_ctrlA = DMAC_CTRLA_BTSIZE(DMA_BUF_SIZE) | DMAC_CTRLA_SRC_WIDTH_WORD | DMAC_CTRLA_DST_WIDTH_WORD;
desc.ul_ctrlB = DMAC_CTRLB_SRC_DSCR_FETCH_DISABLE | DMAC_CTRLB_DST_DSCR_FETCH_DISABLE | DMAC_CTRLB_FC_MEM2MEM_DMA_FC | DMAC_CTRLB_SRC_INCR_INCREMENTING | DMAC_CTRLB_DST_INCR_FIXED;
desc.ul_descriptor_addr = 0;
SPI_Enable(SPI0);
dmac_channel_multi_buf_transfer_init(DMAC, DMA_CH, &desc);
dmac_channel_enable(DMAC, DMA_CH);
Serial.println("*****");
while (!dmac_channel_is_transfer_done(DMAC, DMA_CH)) { Serial.print('X'); }
Serial.print("SR : "); Serial.println(SPI0->SPI_SR, HEX);
Serial.print("TDR : "); Serial.println(SPI0->SPI_TDR, HEX);
Serial.print("PSR : "); Serial.println(PIOA->PIO_PSR, HEX); //PIO_SODR
Serial.print("OSR : "); Serial.println(PIOA->PIO_OSR, HEX);
Serial.println(DMAC->DMAC_CH_NUM[0].DMAC_SADDR , HEX);
Serial.println(DMAC->DMAC_CH_NUM[0].DMAC_DADDR, HEX);
Serial.println("-----");
}
I use mainly this example : https://ww1.microchip.com/downloads/en/Appnotes/Atmel-42291-SAM3A-3U-3X-4E-DMA-Controller-DMAC_ApplicationNote_AT07892.pdf#_OPENTOPIC_TOC_PROCESSING_d91e3076
And here is the datasheet of the µc : https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-11057-32-bit-Cortex-M3-Microcontroller-SAM3X-SAM3A_Datasheet.pdf
You can see at the bottom of my code sevral prints, from them I had many idea : does the PIO could block the data ? Does the address PIO_PA26A_SPI0_MOSI could work ? Could the SPI block the data because conditions are not met ?
Any idea is welcomed, I'm on this for some time now.
Edit : SPI is not a necessity, the idea is to send data without length limit (unlike UART). I'm considering using SSC.
答案1
得分: 0
我设法解决了,但不是用SPI,而是使用微控制器的SSC(它支持I²S并自动使用DMA):
uint32_t liste[] PROGMEM = { 0x8F66F1, 0x0, 0xAAAAAB }; //要发送的数据
#define DMA_BUF_SIZE (sizeof(liste) / sizeof(liste[0])) //DMA缓冲区大小
uint32_t i;
void setup() {
uint clk_div = 0x90; //所需的时钟分频器
clk_div = (clk_div / 24) / DMA_BUF_SIZE;
clk_div = floor(clk_div + 0.5);
clk_div = clk_div * 24 * DMA_BUF_SIZE; //调整时钟分频器 -> MCK/2*clk_div
PMC->PMC_WPMR = 0x504D4300; //禁用PMC保护
PMC->PMC_PCER0 = (1 << ID_SSC); //启用SSC时钟
PMC->PMC_SCER |= 0x100; //启用时钟
PIOA->PIO_WPMR = 0x50494F00; //禁用Port I/O A保护
PIOA->PIO_PDR = PIO_PDR_P14 | PIO_PDR_P15 | PIO_PDR_P16; //I/O由外设控制
PIOA->PIO_ABSR |= PIO_PA14B_TK | PIO_PA15B_TF | PIO_PA16B_TD; //将I/O分配给SSC
SSC->SSC_CR = SSC_CR_RXDIS | SSC_CR_TXDIS | SSC_CR_SWRST; //禁用和重置SSC
SSC->SSC_WPMR = 0x53534300; //禁用SSC保护
SSC->SSC_IDR = 0xFFFFFFFF; //禁用中断
SSC->SSC_IER = 0x00000000; //禁用中断(另一种方式)
SSC->SSC_CMR = clk_div; //时钟管理
SSC->SSC_TFMR = SSC_TFMR_DATLEN(0x18) | SSC_TFMR_MSBF | SSC_TFMR_DATNB(0); //数据传输管理
SSC->SSC_TCMR = SSC_TCMR_CKS_MCK | SSC_TCMR_CKO_CONTINUOUS | SSC_TCMR_START_CONTINUOUS | SSC_TCMR_STTDLY(0); //传输期间的时钟管理
SSC->SSC_CR = SSC_CR_TXEN; //启用SSC传输
}
void loop() {
for (i = 0; i < DMA_BUF_SIZE; i++) {
ssc_write((Ssc*)SSC, (uint32_t)liste[i]); //SSC传输
}
}
英文:
I managed to solve it but not with SPI, I use the SSC of the µcontroller (which does I²S and uses DMA automatically) :
uint32_t liste[] PROGMEM = { 0x8F66F1, 0x0, 0xAAAAAB }; //Data to send
#define DMA_BUF_SIZE (sizeof(liste) / sizeof(liste[0])) //Size DMA buffer
uint32_t i;
void setup() {
uint clk_div = 0x90; //Clock divider wanted
clk_div = (clk_div / 24) / DMA_BUF_SIZE;
clk_div = floor(clk_div + 0.5);
clk_div = clk_div * 24 * DMA_BUF_SIZE; //Clock divider adjusted -> MCK/2*clk_div
PMC->PMC_WPMR = 0x504D4300; //Desactivation protection PMC
PMC->PMC_PCER0 = (1 << ID_SSC); //Activation SSC clock
PMC->PMC_SCER |= 0x100; //Activation clock
PIOA->PIO_WPMR = 0x50494F00; //Desactivation protection Port I/O A
PIOA->PIO_PDR = PIO_PDR_P14 | PIO_PDR_P15 | PIO_PDR_P16; //I/O controlled by the peripheral
PIOA->PIO_ABSR |= PIO_PA14B_TK | PIO_PA15B_TF | PIO_PA16B_TD; //Assignation of I/O to SSC
SSC->SSC_CR = SSC_CR_RXDIS | SSC_CR_TXDIS | SSC_CR_SWRST; //Desactivation and reset SSC
SSC->SSC_WPMR = 0x53534300; //Desactivation protection SSC
SSC->SSC_IDR = 0xFFFFFFFF; //Desactivation Interrupts
SSC->SSC_IER = 0x00000000; //Desactivation Interrupts bis
SSC->SSC_CMR = clk_div; //Clock management
SSC->SSC_TFMR = SSC_TFMR_DATLEN(0x18) | SSC_TFMR_MSBF | SSC_TFMR_DATNB(0); //Data transfert management
SSC->SSC_TCMR = SSC_TCMR_CKS_MCK | SSC_TCMR_CKO_CONTINUOUS | SSC_TCMR_START_CONTINUOUS | SSC_TCMR_STTDLY(0); //Clock during transfert management
SSC->SSC_CR = SSC_CR_TXEN; //Activation transmission SSC
}
void loop() {
for (i = 0; i < DMA_BUF_SIZE; i++) {
ssc_write((Ssc*)SSC, (uint32_t)liste[i]); //Transmission SSC
}
}
In case someone try the same thing.
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