Analog Devices VISUALDSP++ 3.5, Manual

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Vi+ Loader Manual 3-17
for 16-Bit Processors
ADSP-219x DSP Loader/Splitter
divided by 2 to obtain the corresponding logical address. The first alias
window of
seg_ext_data
that can accessed properly is range
0x02 A000
to
0x02 AFFF
; this results in the logical range
0x01 5000
to
0x01 57FF
.
Similarly, the addresses of segment
seg_ext_code
can be calculated by
dividing the physical addresses by 4. For example, the alias window
between
0x04 B000
and
0x04 FFFF
can be used, resulting in the logical
addresses
0x01 2C00
to
0x01 3FFF
.
The corresponding .
LDF
file would include the following.
MEMORY {
. . .
seg_int_code {
TYPE(PM RAM) START(0x000000) END(0x000000) WIDTH(24) }
seg_int_data {
TYPE(DM RAM) START(0x008000) END(0x009FFF) WIDTH(16) }
seg_ext_code {
TYPE(PM ROM) START(0x012C00) END(0x013FFF) WIDTH(8) }
seg_ext_data {
TYPE(DM ROM) START(0x015000) END(0x0157FF) WIDTH(8) }
...
}
By default, the
elfloader
emits true EPROM addresses by multiplying
the logical addresses accordingly. The address aliasing, which this example
takes advantage of, can be corrected if the loader is invoked with the
Table 3-4. EPROM Image With No-boot Data
Address range Purpose
0x000000–0x009FFF
Boot stream
0x00A000–0x00AFFF
seg_ext_data
(External read-only data)
0x00B000–0x00FFFF seg_ext_code
(External program)