write data to the address (PC104)--solved

[zhoupeng]

Recently , I want to write data to register of can device. At first I use IO space , so I can't make the device operated. Later, I change to use memory space. I can send data and receive data from the register.

IO space:

/*
---------------------------------------------------
 两个最基本的SJA1000寄存器读写函数
*/
/*unsigned char read_sja(unsigned char RegNum)
{
 unsigned char bValue;

 RegNum &= 0x7F;      //最高位清0

 inport_byte(BASE_ADDRESS+RegNum,bValue);

 return (bValue);
}

void write_sja(unsigned char RegNum, unsigned char bValue)
{
 RegNum &= 0x7F;   //最高位清0
 outport_byte(BASE_ADDRESS+RegNum,bValue);
 delay(50000);
}*/

memory space:

unsigned char read_sja(unsigned char RegNum)
{
 unsigned char data;
 RegNum &= 0x7F;
 data =  * (volatile unsigned char *)((BASE_ADDRESS)+RegNum);
 return (data);
}
void write_sja(unsigned char RegNum, unsigned char data)
{
 RegNum &= 0x7F;
 * (volatile unsigned char *)((BASE_ADDRESS)+RegNum) = data;
}

By the way , not all the PC-104 have can module. If you PC-104 have can module, you can follow the manual. But you must  find out if the operation of register is IO space or memory space.
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