Programming Model

DMA IndustryPack Address Counter

In the direct mode, this counter is programmed with the starting address of the data buffer in IndustryPack memory. The value programed in the IndustryPack address counter is the address that would be used when referencing the IndustryPack memory space from the local bus. Refer to the addressing mapping from the local bus to the IndustryPack bus for different IndustryPack memory widths, described later in this chapter.

The registers which control IP_c and IP_d are not used on the 200/300- Series MVME172.

Note For sDMA operations, the IndustryPack Counter must be cleared before the DMAC is enabled.

ADR/SIZ

 

$FFFBC02C, $44, $5C, $74 (32 bits each)

 

 

 

 

 

 

BIT

31...23

 

22

 

0

 

 

 

 

 

 

NAME

0

 

 

DMA Industry Pack Address Counter

 

 

 

 

 

 

 

OPER

R

 

 

R/W

 

 

 

 

 

 

 

RESET

 

 

 

0 R

 

 

 

 

 

 

 

DMA Byte Counter

In the direct mode, this counter is programmed with the number of bytes of data to be transferred.

For sDMA operations, if the port width is 16 bits, then the byte count must be initialized to an even value; if the width is 32 bits, then the byte count must be initialized to a multiple of four bytes.

If the port width is 8 bits, the byte count value does not have restrictions.

4

http://www.mcg.mot.com/literature

4-41

Page 277
Image 277
Motorola MVME172 manual DMA IndustryPack Address Counter, DMA Byte Counter