SVR5
dma_get_best_mode(D3)
dma_get_best_mode --
determine best transfer mode for DMA command
Synopsis
#include <sys/types.h>
#include <sys/dma.h>
#include <sys/ddi.h>
uchar_t dma_get_best_mode(struct dma_cb *dmacbptr);
Description
dma_get_best_mode determines
the best DMA transfer mode
to use with the DMA operation specified in the command
block whose address is given by dmacbptr.
This function is used for
ISA, EISA, and MCA
DMA channels.
Arguments
dmacbptr-
Pointer to a DMA command block.
Return values
dma_get_best_mode returns a value
that specifies the transfer mode.
This value should be used to set the
``cycles'' field of the
dma_cb(D4)
structure.
Usage
Prior to the call to dma_get_best_mode,
all fields of the command block should have been
initialized except for ``cycles''.
The ``cycles'' field should be initialized using
the return value from dma_get_best_mode.
Context and synchronization
All
contexts.
Hardware applicability
PC-AT compatible platforms
with ISA, EISA, or MCA buses
Version applicability
ddi:
1, 2, 3, 4, 5, 5mp, 6, 6mp, 7, 7mp, 7.1, 7.1mp, 8, 8mp
Future directions
This interface is expected to be replaced or modified in a future release.
References
dma_cb(D4)
``DMA'' in HDK Technical Reference
19 June 2005
© 2005 The SCO Group, Inc. All rights reserved.
OpenServer 6 and UnixWare (SVR5) HDK - June 2005