Texas Instruments TNETE110A, TNETE211, TNETE100A manual Pciint

PCI Configuration Space

r.x.di = addr;

int86(PCI_INT, &r, &r); /* PCI_INT 0x1A */

return (r.x.cx & 0xFF);

}

Normally, the constants in this routine (the values assigned to ah, al, and the opcode for the int86 call) are assigned in the header file for the C code. Their values are inserted as comments to enable the reader to resolve the actual val- ues that are used. The device ID, devid, is known to the driver and is used with another PCI O/S call to find the base addresses needed for this call.

//±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±

//PciRdWord() ± PCI read config word

//Parameters:

//	devid	WORD	pci device	number
//	addr	WORD	address to	read
//

//Return val:

// WORDvalue read

//±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±± WORD PciRdWord(WORD devid, WORD addr)

{

union REGS r;

r.h.ah = PCI_FUNCTION_ID; r.h.al = READ_CONFIG_WORD; r.x.bx = devid;

r.x.di = addr; int86(PCI_INT, &r, &r); return(r.x.cx);

}

This code passes an address >10 if the driver regards the host registers as memory locations (ThunderLAN's first base address register is hardwired as a memory base register), or >14 if the driver treated the host registers as an I/O block (ThunderLAN's second base register is hardwired as an I/O base register). For the I/O port, the following C instruction could be used to put a val- ue into the DIO_ADR host register:

outpw(base_addr+OFF_DIO_ADDR,value);

OFF_DIO_ADDR is a constant for the header file. A memory transfer instruc- tion is used if memory space is used instead of I/O space.

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