2

VMEchip2

TVME

This bit defines the direction in which the DMAC

 

transfers data. When this bit is high, data is transferred to

 

the VMEbus. When it is low, data is transferred to the

 

local bus.

LINC

When this bit is high, the local bus address counter is

 

incremented during DMA transfers. When this bit is low,

 

the counter is not incremented. This bit should normally

 

be set high. In special situations such as transferring data

 

to or from a FIFO, it may be desirable to not increment the

 

counter.

 

VINC

When this bit is high, the VMEbus address counter is

 

incremented during DMA transfers. When this bit is low,

 

the counter is not incremented. This bit should normally

 

be set high. In special situations such as transferring data

 

to or from a FIFO, it may be desirable to not increment the

 

counter.

 

SNP

These bits control the snoop signal lines on the local bus

 

when the DMAC is local bus master and it is not accessing

 

the command table.

 

0

Snoop inhibited

 

1

Snoop enabled

INTE

This bit is used only in the command chaining mode and

 

it is only modified when the DMAC loads the control

 

register from the control word in the command packet.

When this bit in the command packet is set, an interrupt is sent to the local bus interrupter when the command in the packet has been executed. The local bus is interrupted if the DMAC interrupt is enabled.

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Image 136
Motorola MVME172 manual Tvme, Linc, Vinc, Snp, Inte