Why I2C Master core not work?(MAX10) - Why I2C Master core not work?(MAX10) I use DE10-LITE board. I try to use I2C for connect with external ROM. In QSYS, I set up NIOS and I2C Master Core. it is my code GPIO(0) <= '0' WHEN SDA_OE = '1' ELSE 'Z'; GPIO(1) <= '0' WHEN SCL_OE = '1' ELSE 'Z'; SDA <= GPIO(0); SCL <= GPIO(1); u0 : component QSYS port map ( clk_clk => MAX10_CLK1_50, -- clk.clk reset_reset_n => RST, -- reset.reset_n i2c_0_i2c_serial_sda_in => SDA, -- i2c_0_i2c_serial.sda_in i2c_0_i2c_serial_scl_in => SCL, -- .scl_in i2c_0_i2c_serial_sda_oe => SDA_OE, -- .sda_oe i2c_0_i2c_serial_scl_oe => SCL_OE -- .scl_oe ); and i write program code in Eclips like this. i2c_dev = alt_avalon_i2c_open("/dev/i2c_0"); if (NULL==i2c_dev) { printf("Error: Cannot find /dev/i2c_0\n"); //return 1; } while(1) { alt_avalon_i2c_master_target_set(i2c_dev,SLAVE_ROM_ADDR); status=alt_avalon_i2c_enable(i2c_dev); i2c_tx_buf[0] = 0x00; i2c_tx_buf[1] = 0x00; i2c_tx_buf[2] = 0x03; i2c_tx_buf[3] = 0x04; status=alt_avalon_i2c_master_tx(i2c_dev, i2c_tx_buf, 4, 0); } and i connect gpio pins to oscilloscope. but it doesn't send any signals. what is problem? Replies: Re: Why I2C Master core not work?(MAX10) I recommend to check out this example of Master-Slave https://www.macnica.co.jp/business/semiconductor/articles/intel/129485/ is in Japanese but you can get the example files and then translate the bits that you do not understand, the example worked for me.