Overview
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
17-3
Single-write start mode. The DMA process can be started by using a single-write
command to either the descriptor address register in one of the chaining modes or the
source/destination address registers in one of the direct modes.
External control capability. This allows an external agent to start, pause, and check the
status of a DMA transfer that has already been initialized.
Channel continue capability. The channel continue capability allows software the
flexibility of having the DMA controller start with descriptors that have already been
programmed while software continues to build more descriptors in memory.
Channel abort capability. The software can abort a previously initiated transfer by setting
the bit MRn[CA]. The DMA controller terminates all outstanding transfers initiated by the
channel without generating any errors before entering an idle state.
(
Refer to Section 17.2, Functional Description for details on these modes. Figure 17-2 shows the general
DMA operational flow chart.
Figure 17-2. DMA Operational Flow Chart
Table 17-1. Relationship of Modes and Features
Mode
Mode with One Additional Feature
Mode with Two Additional Features
B (Basic)
BD (basic direct)
BDS (BD single-write start)
BC (basic chaining)
BCS (BC single-write start)
Ext (Extended)
ExtD (extended direct)
ExtDS (ExtD single-write start)
ExtC (extended chaining)
ExtCS (ExtC single-write start)
Software Sets 1st Link
Process Link
Last Link?
Is
N
Y
N
Chain or Extended
Done — DMA Halts
Y
Is
Last List?
N
Y
Advance List
Advance
Mode?
In
Link
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...