VisualDSP++ 4.5 Loader and Utilities Manual - Analog Devices

Loader for ADSP-2126x/2136x/2137x SHARC Processors
The linker packs the external memory data in the .dxe file according to
the WIDTH() and PACKING() commands. This is the only valid way to specify
external memory. The correct physical address is in the .dxe file
(selected with WIDTH() and PACKING()) because each 8-bit or 16-bit word
occupies one external address, and there is no logical addressing of external
memory. The loader utility unpacks the data from the .dxe file and
packs the data again into 32-bit words in the loader file (see Table 5-4). In
the loader file, tag INIT_EXT8 is used for 8-bit external packed sections,
and tag INIT_EXT16 is used for 16-bit external packed sections.
Table 5-4. External Packed Sections in .DXE Files Versus Repacked Blocks
in .LDR Files
External
Width
� ZERO_INIT
Address
in .dxe
Packed
in .dxe
WIDTH(8) 0x01000000 0x0000001100
0x01000001 0x0000002200
0x01000002 0x0000003300
Block Address
in .ldr
Repacked to 32-bit
in .ldr
0x01000003 0x0000004400 0x01000000 0x44332211
0x01000004 0x0000005500
0x01000005 0x0000006600
0x01000006 0x0000007700
0x01000007 0x0000008800 0x01000004 0x88776655
WIDTH(16) 0x02000000 0x0000112200
0x02000001 0x0000334400 0x02000000 0x33441122
0x02000002 0x0000556600
0x02000003 0x0000778800 0x02000002 0x77885566
sections are treated like 32-bit ZERO_INIT sections,
meaning the count contains the number of 32-bit zeros.
VisualDSP++ 4.5 Loader and Utilities Manual 5-7