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6.6.3
Element Count
6.6.4
Frame/Array Count
6.6.5
Element/(Frame/Array) Index
6.6.6
Element Count Reload
Element count is a 16-bit unsigned value that specifies the number of elements
in a frame (non-2D) or an array (for 2D transfers). Valid values for the element
count can be anywhere between 1 and 65535. Therefore, the maximum num-
ber of elements in a frame is 65535. Operation is undefined if element count
is zero. Details in section 6.11.
Frame count is also a 16-bit unsigned value and it specifies the number of
frames in a non-2D block transfer or number of arrays in a 2D block transfer.
The maximum number of frames in a block is 65536. Therefore a frame/array
count of 0 is actually one frame/array and frame count of 1 corresponds to 2
frames/arrays. Details in section 6.11.
The 16-bit signed value specified in the element and frame index fields are
used for address modification. These fields are used by the EDMA for address
updates depending on the type of transfer chosen (1D or 2D), FS, and SUM/
DUM fields. The src/dst address is modified by an index whose range is be-
tween –32768 and 32767.
Element index provides an address offset to the next element in a frame. Ele-
ment index is used only for non-2D transfers. This is because 2D transfers do
not allow spacing between elements, and hence the term 'array' is used to de-
fine a group of contiguous elements. Frame index provides an offset to the next
frame in a block.
The 16-bit unsigned element count reload value is used to reload the element
count field once the last element in a frame is transferred. This field is used only
for a non-2D read/write sync (FS=0) transfer since the EDMA has to keep track
of the next element address using the element count. This is necessary for
multi-frame EDMA transfers where frame count value is greater than 0. More
details in section 6.11.1.
EDMA Transfer Parameters
EDMA Controller
6-15
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