PXS20RM Datasheet, PDF (425/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

Enhanced Direct Memory Access (eDMA)
Table 19-35. TCDn Word 7 (TCDn.{biter, control/status}) field descriptions
Name
biter.e_link
Description
Enable channel-to-channel linking
on minor loop complete
Value
This is the initial value copied into the citer.e_link field
when the major loop is completed. The citer.e_link
field controls channel linking during channel
execution. This bit must be equal to the citer.e_link bit
otherwise a configuration error will be reported.
biter[0:5]
or
biter.linkch[0:5]
Beginning “major” iteration count
or
Beginning Link channel number
0 The channel-to-channel linking is disabled.
1 The channel-to-channel linking is enabled.
This is the initial value copied into the citer field or
citer.linkch field when the major loop is completed.
The citer fields controls the iteration count and linking
during channel execution.
if (TCD.biter.e_link = 0) then
No channel-to-channel linking (or chaining) is
performed after the inner "minor" loop is exhausted.
TCD word 5, bits [30:25] are used to form a 15 bit biter
field.
else
After the "minor" loop is exhausted, the eDMA engine
initiates a channel service request at the channel
defined by biter.linkch[5:0] by setting that channel’s
TCD.start bit.
The value contained in biter.linkch[5:0] must not
exceed the number of implemented channels.
biter[6:14]
Beginning “major” iteration count
For this device, bits 0:1 of this field are reserved.
This is the initial value copied into the citer field or
citer.linkch field when the major loop is completed.
The citer fields controls the iteration count and linking
during channel execution.
This 9- or 15-bit count represents the beginning major
loop count for the channel. As the major iteration
count is exhausted, the contents of the entire 16-bit
biter entry is reloaded into the 16-bit citer entry.
When the biter field is initially loaded by software, it
must be set to the same value as that contained in the
citer field.
If the channel is configured to execute a single
service request, the initial values of biter and citer
should be 0x0001.
Freescale Semiconductor
PXS20 Microcontroller Reference Manual, Rev. 1
19-29