Motorola MVME172 manual Den

Models: MVME172

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4

IP2 Chip

ADR/SIZ

 

 

$FFFBC022, $3A, $52, $6A (8 bits each)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OPER

R

R

 

R

R

R

R

 

R

 

S

 

 

 

 

 

 

 

 

 

 

 

 

RESET

0 R

0 R

 

0 R

0 R

0 R

0 R

 

0 R

 

0 R

 

 

 

 

 

 

 

 

 

 

 

 

DEN

 

Setting the DEN bit to a one will enable the DMA

 

 

 

 

function. Software should not write to the DMA control

registers between the time the DEN bit is set and the DMA process is completed. In general, this is true on a per channel basis but there are inter-relationships between the DMA channels/board architecture which require the initialization of certain bits for each pair of DMA channels before the DEN bits can be set. That is, if DMA channels a and b are going to be used concurrently, DMA Control Register 1 should be initialized for both channels before ether channel is enabled. This is also true for DMA channels c and d. Refer to the section on the DMA Enable Function.

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Motorola MVME172 manual Den