Packing In Adsp-218X And Adsp-219X Dsps - Analog Devices VisualDSP++ 3.5 Manual

LDF Commands
group, and whether and where null bytes are to be inserted to preserve
alignment on the target. In this case, null refers to usage; the target ignores
the null byte. Coincidentally, the linker sets these bytes to 0s.
Syntax
The command syntax is:
PACKING (number_of_bytes byte_order_list)
where:
•
number_of_bytes
pack (reorder) before repeating the pattern
•
byte_order_list
writes into memory. Each list entry consists of
byte's number (in a group) at the storage medium (memory) and
follows these rules.
• Parameters are delimited by whitespace characters
• The total number of non-null bytes is
• If null bytes are included, they are labeled

Packing in ADSP-218x and ADSP-219x DSPs

In ADSP-21xx DSPs, some buses (PMA, DMA, PMD, ...) are 24 bits
wide, and some (DMD) are 16 bits wide. Each device's configuration,
placement, and amount of memory is implementation-specific.
Example
If the processor unpacks three 16-bit memory words to build two 24-bit
instruction words, the following unpacked and storage orders could apply
the requisite transfer order. The linker must reorder the bytes into their
unpacked order.
3-34
is an integer specifying the number of bytes to
is the output byte ordering—what the linker
VisualDSP++ 3.5 Linker and Utilities Manual
followed by the
B
number_of_bytes
B0
for 16-Bit Processors