FPGA上でソフトコアCPUを動かす手引き：MAX 10 FPGAで学ぶFPGA開発入門（6）（5/7 ページ）

[大原 雄介，MONOist]

　次はソフトウェアの設定である。Project Templateは「Hello world small」を選んだので自動的に"hello_world_small.c"が生成される（Photo27）。このままだと「Hello from Nios II!」と表示して終わってしまうのだが、これを置き換えるソースコード(ondie_temp.c)がsoftwareフォルダの中に用意されている（List 1）。これをエディタなどで開き、コピーしてhello_world_small.cにペーストする形でプログラムを入れ替える（Photo28）。

Photo27:何というか、説明の必要はまぁないだろう

Photo28:ondie_temp.cをファイルとして追加する方法も何度か試したのだが上手くいかなかった

List 1:
/*
 * main.c
 *
 *  Created on: Oct 29, 2014
 *      Author: apanneer
 */
 
 
//#include "stdio.h"
#include "system.h"
#include "sys/alt_irq.h"
#include "altera_avalon_timer_regs.h"
#include "altera_avalon_pio_regs.h"
#include "altera_modular_adc_sequencer_regs.h"
 
 
 
alt_u8 celsius_lookup(int adc_avg_in);
 
int main()
{
 
	int switch_datain;
 
	volatile int adc_avg=0 ,i;
	printf("*******PIO and On-Die Temp Sensor example********\nChange Switches 1,2, and 3 to change LEDs 1,2 and 3\nThe value of ADC Channel connected to Temperature Sensing Diode is collected every second and is averaged over 64 Samples\n------------------------------------------------------------------------------------------------------");
 
 
	//Starting the ADC sequencer
	IOWR(MODULAR_ADC_0_SEQUENCER_CSR_BASE, 0, 0);
	usleep(10);
	IOWR(MODULAR_ADC_0_SEQUENCER_CSR_BASE, 0, 1);
 
	//Event loop never exits
	while(1)
	{
		// Reads the value from Switch and Displays in the LED
		switch_datain = IORD_ALTERA_AVALON_PIO_DATA(SW_IO_BASE);
		IOWR_ALTERA_AVALON_PIO_DATA(LED_IO_BASE,switch_datain);
		//Giving a 1 Second delay
		usleep(1000000);
 
		adc_avg=0;
		//Getting an average of 64 samples
		for (i=0;i<64;i++)
		{
			int adc_value=IORD(MODULAR_ADC_0_SAMPLE_STORE_CSR_BASE,i);
			adc_avg=adc_avg+adc_value;
		}
 
		printf("\nOn-die temperature = %d",(celsius_lookup(adc_avg/64-3417)-40));
 
	}
	return 0;
}
 
 
 
 
alt_u8 celsius_lookup(int adc_avg_in)
{
	 const alt_u8 celsius_lookup_table[383]={
			165,165,165,164,164,164,163,163,163,162,162,162,161,161,161,160,160,160,
			159,159,159,158,158,158,157,157,157,156,156,156,155,155,155,154,154,154,
			153,153,152,152,152,151,151,151,150,150,150,149,149,149,148,148,148,147,
			147,147,146,146,146,145,145,144,144,144,143,143,143,142,142,142,141,141,
			141,140,140,140,139,139,138,138,138,137,137,137,136,136,136,135,135,135,
			134,134,133,133,133,132,132,132,131,131,131,130,130,129,129,128,128,128,
			128,127,127,126,126,126,125,125,125,124,124,124,123,123,122,122,122,121,
			121,121,120,120,119,119,119,118,118,118,117,117,116,116,116,115,115,114,
			114,114,113,113,113,112,112,111,111,111,110,110,109,109,109,108,108,107,
			107,107,106,106,105,105,105,104,104,103,103,103,102,102,101,101,101,100,
			100,99,99,99,98,98,97,97,96,96,96,95,95,94,94,94,93,93,92,92,91,91,91,90,
			 90,89,89,88,88,88,87,87,86,86,85,85,85,84,84,83,83,82,82,82,81,81,80,80,
			 79,79,78,78,78,77,77,76,76,75,75,74,74,73,73,73,72,72,71,71,70,70,69,69,
			 68,68,67,67,67,66,66,65,65,64,64,63,63,62,62,61,61,60,60,59,59,58,58,57,
			 57,56,56,55,55,55,54,54,53,53,52,52,51,51,50,50,49,49,48,48,47,47,46,46,
			 45,45,44,43,43,42,42,41,41,40,40,39,39,38,38,37,37,36,36,35,35,34,34,33,
			 33,32,31,31,30,30,29,29,28,28,27,27,26,26,25,24,24,23,23,22,22,21,21,20,
			 20,19,18,18,17,17,16,16,15,15,14,13,13,12,12,11,11,10, 9, 9, 8, 8, 7, 7,
			  6, 5, 5, 4, 4, 3, 2, 2, 1, 1, 0 };
 
	//printf("temp = %d",adc_avg_in);
	return (celsius_lookup_table[adc_avg_in]);
 
}
 

List1