Motorola MVME172 用户手册
Programming Model
http://www.mcg.mot.com/literature
4-41
4
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 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.
Series MVME172.
Note
For sDMA operations, the IndustryPack Counter must be
cleared before the DMAC is enabled.
cleared before the DMAC is enabled.
DMA Byte Counter
In the direct mode, this counter is programmed with the number of bytes
of data to be transferred.
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.
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.
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