Firmwares/hifive1-vp/hello/hello.c

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2020-06-18 12:15:52 +02:00
#include <stdint.h>
#include <stdio.h>
#include <unistd.h>
#include "platform.h"
#include "encoding.h"
#define IOF_SPI1_MASK (0x38 | 0x4)
int factorial(int i){
volatile int result = 1;
for (int ii = 1; ii <= i; ii++) {
result = result * ii;
}
return result;
}
unsigned read_adc(unsigned index){
unsigned char txdata[3];
unsigned result=0;
volatile int x;
txdata[0]=0x1;
txdata[1]=(0x8 | (index&0x7))<<4;
txdata[2]=0x0;
GPIO_REG(GPIO_IOF_SEL) &= ~IOF_SPI1_MASK;
GPIO_REG(GPIO_IOF_EN) |= IOF_SPI1_MASK;
SPI1_REG(SPI_REG_FMT) =
SPI_FMT_PROTO(SPI_PROTO_S) |
SPI_FMT_ENDIAN(SPI_ENDIAN_MSB) |
SPI_FMT_DIR(SPI_DIR_RX) |
SPI_FMT_LEN(8);
SPI1_REG(SPI_REG_CSID) = 0;
SPI1_REG(SPI_REG_CSDEF) = 0xFFFF;
SPI1_REG(SPI_REG_SCKDIV) = 7;
SPI1_REG(SPI_REG_SCKMODE) = SPI_SCK_PHA | SPI_SCK_POL; //shifted on the leading edge, sampled on trailing, Inactive state of SCK is logical 1
SPI1_REG(SPI_REG_CSMODE) = SPI_CSMODE_HOLD;
while (SPI1_REG(SPI_REG_TXFIFO) & SPI_TXFIFO_FULL) ;
SPI1_REG(SPI_REG_TXFIFO) = txdata[0];
while ((x = SPI1_REG(SPI_REG_RXFIFO)) & SPI_RXFIFO_EMPTY);
while (SPI1_REG(SPI_REG_TXFIFO) & SPI_TXFIFO_FULL) ;
SPI1_REG(SPI_REG_TXFIFO) = txdata[1];
while ((x = SPI1_REG(SPI_REG_RXFIFO)) & SPI_RXFIFO_EMPTY);
result = (x & 0xFF)<<8;
while (SPI1_REG(SPI_REG_TXFIFO) & SPI_TXFIFO_FULL) ;
SPI1_REG(SPI_REG_TXFIFO) = txdata[2];
while ((x = SPI1_REG(SPI_REG_RXFIFO)) & SPI_RXFIFO_EMPTY);
result += (x & 0xFF);
SPI1_REG(SPI_REG_CSMODE) = SPI_CSMODE_AUTO;
return result&0x03ff;
}
int main()
{
GPIO_REG(GPIO_IOF_EN) |= 0x30000;
int result = factorial (10);
printf("Factorial of 10 is %d\n", result);
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for(unsigned i=0; i<8; ++i)
printf("ADC%u value read is %u\n", i, read_adc(i));
printf("End of execution");
return 0;
}