embeded/ARM2014. 9. 22. 14:38
i.mx283 뒤지다가 영 스펙이 제대로 안나와서 헤매느중..
아무튼 검색을 하다보니 DSP & SIMD로
ARMv5TE 계열에 지원하는 DSP Enchancement 로 몇가지 명령어를 지원하는 것으로 보이지만...
컴파일 옵션에 DSP multiply 정도로 밖에 안나오는것 봐서는
ARMv6 계열의 SIMD에 비하면 정말 미미한 수준의 DSP/멀티미디어 확장일 것으로 보인다.

ARMv5TE 계열인 ARM946의 DSP enhancement instruction
느낌으로는.. 32bit 짜리로 8bit 씩 4개의 데이터에 대한 확장 명령이 존재할 것으로 보여진다.

[링크 : http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dvi0022a/ar01s02s14.html]

QADD, QSUB, QDADD, and QDSUB
Signed Add, Subtract, Double and Add, Double and Subtract, saturating the result to the signed range -2^31 ≤ x ≤ 2^31-1.

Syntax
op{cond} {Rd}, Rm, Rn

where:
op        is one of QADD, QSUB, QDADD, or QDSUB.
cond     is an optional condition code.
Rd         is the destination register.
Rm, Rn  are the registers holding the operands.
[링크 : http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0489e/Cihidceh.html

[링크 : http://www.arm.com/products/processors/technologies/dsp-simd.php]

5TEJ ARMv5 with Thumb, interworking, DSP multiply, double-word instructions, and Jazelle® extensions ARM926EJ-S, ARM1026EJ-S, SC200 
[링크 : http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0491g/CIHGEBDH.html]

DSP enhancement instructions
To improve the ARM architecture for digital signal processing and multimedia applications, DSP instructions were added to the set. These are signified by an "E" in the name of the ARMv5TE and ARMv5TEJ architectures. E-variants also imply T, D, M and I.

The new instructions are common in digital signal processor architectures. They include variations on signed multiply–accumulate, saturated add and subtract, and count leading zeros. 

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