Advantech ITA-1611 Series, User Manual

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ITA-1611 User Manual 52
6.1 Function Call Reference
ICH SMBUS Access code
?The following codes simulate BIOS visiting SMBUS. Borland C++ 3.1 compiles
OK. This has be tested under DOS, nut not other OS?
#define SMBUS_PORT 0x400 //SMB_BASE?0x400
typedefunsigned char BYTE;
////////////////////////////////////////////////////////////////////////////////////////////////////
/
BYTEsmbus_read_byte(BYTE addr, BYTE offset)
//Read value of SMBUS Register byte. One byte value is returned each time,
among which addr is slave address,like 0x40?offset is register offset
{
int i;
BYTE data;
outportb(SMBU 4, (addr | 1)); //Write slave address to SMB_BASE
+ 4 (Before reading, please set slave address bit 0 to 1, so there is addr|1)
newiodelay(); //delay
newiodelay(); //delay
chk_smbus_ready(); //Determine if SMBUS is ready
outportb(SMBU 3, offset); //Write register offset to SM 3
newiodelay(); //delay
newiodelay(); //delay
outportb(SMBU 2, 0x48); //Write SBMBUS command toSMB_BASE
+ 2, 0x48 means starting Byte data transmission
newiodelay(); //delay
newiodelay(); //delay
for (i = 0; i <= 0x100; i++)
{
newiodelay(); //long time delay
}
chk_smbus_ready(); //Determine if SMBUS is ready
return(inportb(SMBU 5)); //Read byte value from SM 5
}
////////////////////////////////////////////////////////////////////////////////////////////////////
/
voidsmbus_write_byte(BYTE addr, BYTE offset, BYTE value)
//Write SMBUS Register byte value. One byte value can be written each time,
among which addr indicates slave address, like 0x40; offset is register offset;
value is the value to be written
{
int i;
outportb(SMBU 4, addr); //Write slave address to SM 4
(Please set slave address bit 0 to 0 before writing)
moredelay(); //long time delay
moredelay(); //long time delay