It will be a pain for you to get the 8051 type processor to work with the 8237A. The 8051 does not have a bus that supports surrender to a DMA controller and you would have to thus do two main things...

1) Use buffer chips like 74HC244/74HC245's between the 8051 and the DMA controller to isolate the bus during DMA cycles.

2) Have the 8051 poll the bus request line from 8237A so that the 8051 will know to stay away from memory during DMA cycles.

Both of these requirements mean that it would be just as efficient to simply toss the 8237A chip into the mud puddle and use the 8051 to block move the data in software.

Another thing to consider.....If you are doing a project that is something that may go into a production volume then I would discourage the 8237 chip simply on the virtue that it is not a chip recommended for new designs. Most manufacturers that used to make this chip have discontinued it for a number of years now.

Michael Karas