20.4.2 DMA channels with no triggering capability
The other channels of the DMA MUX provide the normal routing functionality as
described in
20.4.3 "Always enabled" DMA sources
In addition to the peripherals that can be used as DMA sources, there are 10 additional
DMA sources that are "always enabled". Unlike the peripheral DMA sources, where the
peripheral controls the flow of data during DMA transfers, the "always enabled" sources
provide no such "throttling" of the data transfers. These sources are most useful in the
following cases:
• Doing DMA transfers to/from GPIO—Moving data from/to one or more GPIO pins,
either un-throttled (that is as fast as possible), or periodically (using the DMA
triggering capability).
• Doing DMA transfers from memory to memory—Moving data from memory to
memory, typically as fast as possible, sometimes with software activation.
• Doing DMA transfers from memory to the external bus (or vice-versa)—Similar to
memory to memory transfers, this is typically done as quickly as possible.
• Any DMA transfer that requires software activation—Any DMA transfer that should
be explicitly started by software.
In cases where software should initiate the start of a DMA transfer, an "always enabled"
DMA source can be used to provide maximum flexibility. When activating a DMA
channel via software, subsequent executions of the minor loop require a new "start" event
be sent. This can either be a new software activation, or a transfer request from the DMA
channel MUX. The options for doing this are:
• Transfer all data in a single minor loop. By configuring the DMA to transfer all of
the data in a single minor loop (that is major loop counter = 1), no re-activation of the
channel is necessary. The disadvantage to this option is the reduced granularity in
determining the load that the DMA transfer will incur on the system. For this option,
the DMA channel should be disabled in the DMA channel MUX.
Functional description
K53 Sub-Family Reference Manual, Rev. 6, Nov 2011
432
Freescale Semiconductor, Inc.
Содержание K53 Series
Страница 2: ...K53 Sub Family Reference Manual Rev 6 Nov 2011 2 Freescale Semiconductor Inc...
Страница 58: ...K53 Sub Family Reference Manual Rev 6 Nov 2011 58 Freescale Semiconductor Inc...
Страница 70: ...Orderable part numbers K53 Sub Family Reference Manual Rev 6 Nov 2011 70 Freescale Semiconductor Inc...
Страница 168: ...Human machine interfaces HMI K53 Sub Family Reference Manual Rev 6 Nov 2011 168 Freescale Semiconductor Inc...
Страница 206: ...Boot K53 Sub Family Reference Manual Rev 6 Nov 2011 206 Freescale Semiconductor Inc...
Страница 218: ...Security Interactions with other Modules K53 Sub Family Reference Manual Rev 6 Nov 2011 218 Freescale Semiconductor Inc...
Страница 342: ...PMC Memory Map Register Definition K53 Sub Family Reference Manual Rev 6 Nov 2011 342 Freescale Semiconductor Inc...
Страница 362: ...Functional description K53 Sub Family Reference Manual Rev 6 Nov 2011 362 Freescale Semiconductor Inc...
Страница 384: ...Initialization application information K53 Sub Family Reference Manual Rev 6 Nov 2011 384 Freescale Semiconductor Inc...
Страница 406: ...Application Information K53 Sub Family Reference Manual Rev 6 Nov 2011 406 Freescale Semiconductor Inc...
Страница 424: ...Functional Description K53 Sub Family Reference Manual Rev 6 Nov 2011 424 Freescale Semiconductor Inc...
Страница 514: ...Initialization application information K53 Sub Family Reference Manual Rev 6 Nov 2011 514 Freescale Semiconductor Inc...
Страница 524: ...Functional Description K53 Sub Family Reference Manual Rev 6 Nov 2011 524 Freescale Semiconductor Inc...
Страница 546: ...Restrictions on Watchdog Operation K53 Sub Family Reference Manual Rev 6 Nov 2011 546 Freescale Semiconductor Inc...
Страница 594: ...Interrupts K53 Sub Family Reference Manual Rev 6 Nov 2011 594 Freescale Semiconductor Inc...
Страница 628: ...Functional description K53 Sub Family Reference Manual Rev 6 Nov 2011 628 Freescale Semiconductor Inc...
Страница 702: ...Flash Operation in Low Power Modes K53 Sub Family Reference Manual Rev 6 Nov 2011 702 Freescale Semiconductor Inc...
Страница 772: ...Functional description K53 Sub Family Reference Manual Rev 6 Nov 2011 772 Freescale Semiconductor Inc...
Страница 808: ...Initialization Application Information K53 Sub Family Reference Manual Rev 6 Nov 2011 808 Freescale Semiconductor Inc...
Страница 864: ...Application information K53 Sub Family Reference Manual Rev 6 Nov 2011 864 Freescale Semiconductor Inc...
Страница 894: ...DAC Interrupts K53 Sub Family Reference Manual Rev 6 Nov 2011 894 Freescale Semiconductor Inc...
Страница 908: ...Functional Description K53 Sub Family Reference Manual Rev 6 Nov 2011 908 Freescale Semiconductor Inc...
Страница 920: ...Functional Description K53 Sub Family Reference Manual Rev 6 Nov 2011 920 Freescale Semiconductor Inc...
Страница 926: ...Functional Description K53 Sub Family Reference Manual Rev 6 Nov 2011 926 Freescale Semiconductor Inc...
Страница 1092: ...FTM Interrupts K53 Sub Family Reference Manual Rev 6 Nov 2011 1092 Freescale Semiconductor Inc...
Страница 1114: ...Functional description K53 Sub Family Reference Manual Rev 6 Nov 2011 1114 Freescale Semiconductor Inc...
Страница 1156: ...Functional description K53 Sub Family Reference Manual Rev 6 Nov 2011 1156 Freescale Semiconductor Inc...
Страница 1304: ...On The Go Operation K53 Sub Family Reference Manual Rev 6 Nov 2011 1304 Freescale Semiconductor Inc...
Страница 1334: ...USB Voltage Regulator Module Signal Descriptions K53 Sub Family Reference Manual Rev 6 Nov 2011 1334 Freescale Semiconductor Inc...
Страница 1388: ...Initialization Application Information K53 Sub Family Reference Manual Rev 6 Nov 2011 1388 Freescale Semiconductor Inc...
Страница 1514: ...Application information K53 Sub Family Reference Manual Rev 6 Nov 2011 1514 Freescale Semiconductor Inc...
Страница 1622: ...Software restrictions K53 Sub Family Reference Manual Rev 6 Nov 2011 1622 Freescale Semiconductor Inc...
Страница 1694: ...Initialization application information K53 Sub Family Reference Manual Rev 6 Nov 2011 1694 Freescale Semiconductor Inc...
Страница 1704: ...Functional description K53 Sub Family Reference Manual Rev 6 Nov 2011 1704 Freescale Semiconductor Inc...
Страница 1734: ...Application information K53 Sub Family Reference Manual Rev 6 Nov 2011 1734 Freescale Semiconductor Inc...
Страница 1800: ...Application information K53 Sub Family Reference Manual Rev 6 Nov 2011 1800 Freescale Semiconductor Inc...
Страница 1822: ...K53 Sub Family Reference Manual Rev 6 Nov 2011 1822 Freescale Semiconductor Inc...