DMA_TCDn_CSR field descriptions (continued)
Field
Description
If this flag is set, the channel is requesting service. The eDMA hardware automatically clears this flag after
the channel begins execution.
0
The channel is not explicitly started.
1
The channel is explicitly started via a software initiated service request.
22.3.31 TCD Beginning Minor Loop Link, Major Loop Count (Channel
Linking Enabled) (DMA_TCDn_BITER_ELINKYES)
If the TCDn_BITER[ELINK] bit is set, the TCDn_BITER register is defined as follows.
Address: 4000_8000h base + 101Eh (32d × i), where i=0d to 15d
Bit
15
14
13
12
11
10
9
8
Read
Write
Reset
Bit
7
6
5
4
3
2
1
0
Read
Write
Reset
* Notes:
x = Undefined at reset.
•
DMA_TCDn_BITER_ELINKYES field descriptions
Field
Description
15
ELINK
Enables channel-to-channel linking on minor loop complete
As the channel completes the minor loop, this flag enables the linking to another channel, defined by
BITER[LINKCH]. 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 disables, the BITER value
extends 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: When the software loads the TCD, this field must be set equal to the corresponding CITER field;
otherwise, a configuration error is reported. As the major iteration count is exhausted, the
contents of this field are reloaded into the CITER field.
0
The channel-to-channel linking is disabled
1
The channel-to-channel linking is enabled
14–13
Reserved
This field is reserved.
12–9
LINKCH
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 at the channel defined by this field by setting that channel’s
TCDn_CSR[START] bit.
Table continues on the next page...
Memory map/register definition
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
474
Freescale Semiconductor, Inc.
