A good example of such a controller chip is the
National Instruments TNT4882. This 100-pin chip contains both a
complete ISA bus interface and a complete GPIB interface. You only need
to provide a 40-MHz clock signal to create a fully functional GPIB
controller. The chip appears to the PC as a set of read/write registers
accessible as 16 consecutive I/O ports. Writing appropriate values into
the registers allows you to control the GPIB bus any way you want.
Normally you don't program the interface chip's registers directly either. When you buy a GPIB card for a PC, it comes with software drivers that provide a set of high-level functions you can call to communicate with and and control the instruments on the GPIB. Since these functions differ from one board manufacturer to another, they won't be discussed here.
However for completeness here is a list of GPIB controllers that exist or have existed:
Besides these chips there are a number of other vendors like INES ( Germany ) CEC ( Capital Equipment USA ) and IO-Data / Data translation that have made their own chips. these are based either on the TMS9914 or the NEC UPD7210. Some are even switchable by pulling a certain pin high or low. The functionality remains but in some cases FIFO's have been added inside the chip or the output drivers are on board.
Normally you don't program the interface chip's registers directly either. When you buy a GPIB card for a PC, it comes with software drivers that provide a set of high-level functions you can call to communicate with and and control the instruments on the GPIB. Since these functions differ from one board manufacturer to another, they won't be discussed here.
However for completeness here is a list of GPIB controllers that exist or have existed:
- Intel 8291: The basic slave GPIB chip. Needs a 8292 to become master.
- Intel 8292: Master functionality for 8291.
- Intel 8293: The IO drivers for the 8291 / 8292 chips.
- Motorola 68488: GPIB for the 68xx family from
- NEC uPD7210: Most used GPIb controller. Is basically an integration of the Intel chipset into a single chip.
- Philips HEF4743: Slave controller only.
- TI TMS9914: the grand-daddy of them all. For TI processors with bit reversed data bus ( can be a real pain if writing software for it. If the datasheet talks about bit 1 in a register you need to write bit 6 !.
- NI TNT488: All in one GPIB controller with integrated drivers.
feature standard mode and ISA mode. ISA mode changes pinout to hook it
up to a PC motherboard directly.
Besides these chips there are a number of other vendors like INES ( Germany ) CEC ( Capital Equipment USA ) and IO-Data / Data translation that have made their own chips. these are based either on the TMS9914 or the NEC UPD7210. Some are even switchable by pulling a certain pin high or low. The functionality remains but in some cases FIFO's have been added inside the chip or the output drivers are on board.
Wed, 2010-09-01 18:08
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