ADSP-2126x SHARC Processor Hardware Reference
2-13
Processing Elements
• The DSP does not provide inexact flags. An inexact flag is an
exception flag whose bit position is inexact. The inexact exception
occurs if the rounded result of an operation is not identical to the
exact (infinitely precise) result. Thus, an inexact exception always
occurs when an overflow or an underflow occurs.
• NAN (Not-A-Number) inputs generate an invalid exception and
return a quiet NAN (all 1s).
• Denormal operands, using denormalized (or tiny) numbers, flush
to zero when input to a computational unit and do not generate an
underflow exception. A denormal operand is one of the float-
ing-point operands with an absolute value too small to represent
with full precision in the significant. The denormal exception
occurs if one or more of the operands is a denormal number. This
exception is never regarded as an error.
• The processor supports round-to-nearest and round-toward-zero
modes, but does not support round-to-+Infinity and round-to
--Infinity.
IEEE single-precision floating-point data uses a 23-bit mantissa with an
8-bit exponent plus sign bit. In this case, the computation unit sets the
eight LSBs of floating-point inputs to zeros before performing the opera-
tion. The mantissa of a result rounds to 23 bits (not including the hidden
bit), and the 8 LSBs of the 40-bit result clear to zeros to form a 32-bit
number, which is equivalent to the IEEE standard result.
In fixed-point to floating-point conversion, the rounding boundary is
always 40 bits, even if the
RND32
bit is set.
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 ...