RISC-V: Difference between revisions
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* 5-Bits specify register. 33 registers (r0 is always 0). 4-bits will get you 16, 3-Bits will get you 8. |
* 5-Bits specify register. 33 registers (r0 is always 0). 4-bits will get you 16, 3-Bits will get you 8. |
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* All the 32-bit instructions in the base ISA have their lowest two bits set to 11 |
* All the 32-bit instructions in the base ISA have their lowest two bits set to 11 |
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xxxxxxxxxxxxxxaa 16-bit (aa != 11) |
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xxxxxxxxxxxbbb11 32-bit (bbb != 111) |
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xxxxxxxxxx011111 48-bit |
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xxxxxxxxx0111111 64-bit |
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xnnnxxxxx1111111 (80+16*nnn)-bit, nnn != 111 |
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x111xxxxx1111111 Reserved for ≥192-bits |
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* [http://stackoverflow.com/questions/29618439/what-is-the-size-of-integer-in-8-bit-16-bit-32-bit-processors-microcontrollersOn an 8-bit Atmel AVR Arduino, sizeof(int) returns 2 (e.g. 16-bits) when compiled with GCC 4.3.2 (WinAVR 20081205)] |
* [http://stackoverflow.com/questions/29618439/what-is-the-size-of-integer-in-8-bit-16-bit-32-bit-processors-microcontrollersOn an 8-bit Atmel AVR Arduino, sizeof(int) returns 2 (e.g. 16-bits) when compiled with GCC 4.3.2 (WinAVR 20081205)] |
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Revision as of 06:51, 2 November 2016
Minimum Sized ISA
- 5-Bits specify register. 33 registers (r0 is always 0). 4-bits will get you 16, 3-Bits will get you 8.
- All the 32-bit instructions in the base ISA have their lowest two bits set to 11
xxxxxxxxxxxxxxaa 16-bit (aa != 11) xxxxxxxxxxxbbb11 32-bit (bbb != 111) xxxxxxxxxx011111 48-bit xxxxxxxxx0111111 64-bit xnnnxxxxx1111111 (80+16*nnn)-bit, nnn != 111 x111xxxxx1111111 Reserved for ≥192-bits