Texas Instruments TNETE100A, TNETE211, TNETE110A manual Registers

External Devices

Writing to the NetSio register involves writing a >000 to the host register DIO_ADR, then writing to the DIO_DATA host register. Control of the EEPROM interface shifts to the bits in NetSio when a write takes place to the DIO_DATA host register. Following is an example of how one might read a byte of data from the EEPROM, using the control bits in NetSio from the internal register block.

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

//EeRdByte() ± read byte of data from EEPROM (see Exel XL24C02 device specification)

//

//Parameters:

//	base_addr	WORD	base address of TLAN internal
		registers
//	addr	WORD	address to read
//

//Return val:

// BYTEvalue read //±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±

BYTE EeRdByte(WORD base_addr, WORD addr)

{

int i,ips,tmp;

CritOn();

CritOn turns off the interrupts. Remember that there are two possible control points for reading and writing to the EEPROM. This is an attempt to avoid a control shift and avoid loss of focus on just which byte, word, or double word one accesses, since accessing the EEPROM is a relatively long process.

// send EEPROM start sequence

set(ECLOK); set(EDATA); set(ETXEN); clr(EDATA); clr(ECLOK);

ThunderLAN Registers 2-27