ADSP-2126x Memory Map
5-12
ADSP-2126x SHARC Processor Hardware Reference
Normal word address space is also used by the program sequencer
to fetch 48-bit instructions. Note that a 48-bit fetch spans three
columns that can lead to a different address range between instruc-
tion fetches and data fetches (
).
Normal word address space can also optionally be used to fetch
40-bit data (from three columns) if the
IMDWx
(Internal Memory
Data Width) bit in the
SYSCTL
register is set. There are two bits in
the
SYSCTL
register,
IMDW0
and
IMDW1
, which determine whether
access to each block is 32 or 40 bits.
“Accessing Memory” on page 5-22.
The I/O processor’s memory-mapped registers control the system configu-
ration of the DSP and I/O operations. For information about the I/O
Processor, see
. These registers occupy consecu-
tive 32-bit locations in this region.
If a program uses long word addressing (forced with the
LW
mnemonic) to
access this region, the access is only to the addressed 32-bit register, rather
than the two adjacent I/O processor registers. The register contents are
transferred on bits 31–0 of the data bus.
Memory Organization and Word Size
The DSP’s internal memory is organized as four 16-bit wide by 64K high
columns. These columns of memory are addressable as a variety of word
sizes:
• 64-bit long word data (four columns)
• 48-bit instruction words or 40-bit extended-precision normal word
data (3 columns)
Summary of Contents for ADSP-21261 SHARC
Page 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Page 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Page 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Page 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Page 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Page 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Page 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Page 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Page 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Page 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Page 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Page 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...