K60P100M100SF2RM Datasheet, PDF (478/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Memory map/register definition
DMA_TCDn_CITER_ELINKYES field descriptions
Field
15
ELINK
Description
Enable channel-to-channel linking on minor-loop complete
As the channel completes the minor loop, this flag enables linking to another channel, defined by the
LINKCH field. The link target channel initiates a channel service request via an internal mechanism that
sets the TCDn_CSR[START] bit of the specified channel.
If channel linking is disabled, the CITER value is extended to 15 bits in place of a link channel number. If
the major loop is exhausted, this link mechanism is suppressed in favor of the MAJORELINK channel
linking.
NOTE: This bit must be equal to the BITER[ELINK] bit. Otherwise, a configuration error is reported.
14–13
Reserved
12–9
LINKCH
8–0
CITER
0 The channel-to-channel linking is disabled
1 The channel-to-channel linking is enabled
This read-only field is reserved and always has the value zero.
Link Channel Number
If channel-to-channel linking is enabled (ELINK = 1), then after the minor loop is exhausted, the eDMA
engine initiates a channel service request to the channel defined by these four bits by setting that
channel’s TCDn_CSR[START] bit.
Current Major Iteration Count
This 9-bit (ELINK = 1) or 15-bit (ELINK = 0) count represents the current major loop count for the channel.
It is decremented each time the minor loop is completed and updated in the transfer control descriptor
memory. After the major iteration count is exhausted, the channel performs a number of operations (e.g.,
final source and destination address calculations), optionally generating an interrupt to signal channel
completion before reloading the CITER field from the beginning iteration count (BITER) field.
NOTE: When the CITER field is initially loaded by software, it must be set to the same value as that
contained in the BITER field.
NOTE: If the channel is configured to execute a single service request, the initial values of BITER and
CITER should be 0x0001.
21.3.27 TCD Current Minor Loop Link, Major Loop Count (Channel
Linking Disabled) (DMA_TCD_CITER_ELINKNO)
If TCDn_CITER[ELINK] is cleared, the TCDn_CITER register is defined as follows.
Addresses: 4000_8000h base + 1016h offset + (32d × n), where n = 0d to 15d
Bit 15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Read
Write
CITER
Reset x* x* x* x* x* x* x* x* x* x* x* x* x* x* x* x*
* Notes:
• x = Undefined at reset.
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
478
Freescale Semiconductor, Inc.