Having problem with TNT 4882 working w/ Blackfin

[jiangliang]

Hi Everyone

I'm currently using TNT4882 chip to provide GPIB I/F for my application, but the thing is when I declare a address to the TNT chip, and scan from MAX, I will found two address in MAX, one is the address I declared, and one is like 16 less.

e.g. I declared address 28, in MAX I will see both address 28 and 12 are displayed.

and if we declared address less then 16, the MAX will found nothing at all.

BTW, I didn't have any other instrument in GPIB bus.

Could anyone give me some advice? Thanks in advance!

[Steven_T]

Hello Jiangliang,

Would you be able to share your initialization routine?

My hunch is that you did not disable the second address when initializing the TNT4882 with the primary address.  The best way to perform addressing is to write 0x31 to ADMR, write the lower primary address to ADR (this will enable talking and listening on adr0), disable reading and writing on the second address (by writing 0xE0 to ADR).

I hope this helps,

Steven T.