communication between TNT4882and uC

[Marco_C]

I would appreciate if someone would explain me communication between TNT4882 chip and microcontroller.

TNT4882 has a address and data bus so uC addresses registers in which he wants to write or from which he wants to read from.

TNT4882 is 488.2 compliant and that means he understands common commands like IDN? or OPC? etc.

When I send IDN command (or any other commad), what does uC writes in TNT4882 registers?

When do I use 16-bit data transfers?

Thank you

[Collin M]

I'll answer your specific questions below:

>>TNT4882 is 488.2 compliant and that means he understands common commands like IDN? or OPC? etc.
The TNT4882 itself does not "understand" data transfers like *IDN?. It just provides the hardware interface for the firmware/driver to receive these transfers from another GPIB device. The TNT4882 does handle true GPIB commands such as MTA (my talk address) and GET (group execute trigger) completely in hardware. From the TNT4882's perspective, *IDN? is just an arbitrary data transfer so it does no interpretation of it.

>>When I send IDN command (or any other commad), what does uC writes in TNT4882 registers?
You are essentially asking how to write a driver. Can you be a little more specific? Have you looked at the application notes online and looked at the software sections of the TNT4882 programming manual?

>>When do I use 16-bit data transfers?
The TNT4882 has a FIFO for GPIB data transfers that can be accessed either 8-bits or 16-bits per access. It is possible to only use 8-bit accesses. This might simplify the firmware and physical routing of the signals between the TNT4882 and uC. Of course, 8-bit transfers are exactly half as efficient as 16-bit transfers. Accesses to registers other than the FIFO must be 8-bit accesses.


I suggest you review the software section in the TNT4882 manual. It may also be beneficial to review chapter 4 of the TNT5002 manual as the TNT4882 and TNT5002 are software compatible. The TNT5002 manual is organized differently than the TNT4882 manual.

[MichaelChaney]

Hi Marco,

Collin has some great advice.  I just wanted to point you to the resources he's talking about.  To reiterate what collin said, be sure to pay special attention and follow all the instruction in Chaper 4 Programming Considerations of either the TNT4882 Programmer Reference Manual or the TNT5002 Technical Reference Manual.

Thanks,