ADSP-2126x SHARC Processor Hardware Reference
4-21
Data Address Generators
64-bit bus, and the odd numbered register – 1 value (
I0
or
B2
in this
example) transfers on the upper half (bits 63-32) of the bus.
In both the even and odd numbered cases, the explicitly specified DAG
register sources or sinks bits 31-0 of the long word addressed memory.
For implicit moves and long word accesses that use the
PX
registers, as for
example:
I0 = PX;
equates to
I0 = PX1;
only the contents of the
PX1
register are written into I0. However, the fol-
lowing example:
PX = I0;
equates to
PX1 = PX2 = I0;
.
DAG Register Transfer Restrictions
The two types of transfer restrictions are hold-off conditions and illegal
conditions that the DSP does not detect.
For certain instruction sequences involving transfers to and from DAG
registers, an extra (
NOP
) cycle is automatically inserted by the processor. In
case where an instruction that loads a DAG register is followed by an
instruction that uses any register in the same DAG register pair
1
for data
addressing, modify instructions, or indirect jumps, the DSP inserts an
extra (
NOP
) cycle between the two instructions. This hold-off occurs
Figure 4-7. Long Word DAG Register-to-Data Register Transfers
EXPLICIT (NAMED)
DAG1 OR DAG2 REGISTERS
0
31
31
0
63
DM OR PM DATA BUS
IMPLICIT (NAMED + OR - 1)
DAG1 OR DAG2 REGISTERS
0
31
Содержание ADSP-21261 SHARC
Страница 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Страница 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Страница 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Страница 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Страница 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...