CONT_REG

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Dear TA's, Where does bit 9, bit 8 and bit 6-0 come from fro the CONT_REG? Since we are designing this part of the circuit, do we just leave these bits as inputs?

-- Ko-Hua Chu (chuk@ecf.toronto.edu), February 18, 1999

Answers

Your DMA controller is just like any other peripheral device on the 68000 bus. In ece341, when you wanted to use the PIT, you had to write to certain control registers to configure it. Things are no different your circuit.

In this lab, the CONT_REG is used to control certain features of your DMA circuit. The values in the register are written to the register by a test program (that you have written) running on the 68000.

-- Steven Caranci (caranci@eecg.toronto.edu), February 18, 1999.


count is the number of words to be transferred.

-- Steven Caranci (caranci@eecg.toronto.edu), February 22, 1999.

Shouldn't the CONT_REG be made up of 10 bits rather than 9? I assumed COUNT would be made up of 8 bits since we will be adding it to the address in the ADDR_REG but the lab only shows 7 bits for COUNT. Please clear this up for me. Thanks.

-- Confused (confused@ecf.toronto.edu), February 19, 1999.

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