Re: Proposal: Supervisor Timer CSR and Virtual Supervisor Timer CSR
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Greg Favor
A few other small nits: - Besides by S-mode and M-mode, the stimecmp CSR is accessible by HS-mode; and is accessible by VS-mode as well (during which the vstimecmp CSR contents substitute for stimecmp
contents). - The vstimecmp CSR is indirectly read/write accessible during VS-mode (as well as directly during M-mode and HS-mode). - The *stimecmp CSR's are shown as having bits [11:0] and they are shown as TBD. They instead should have the same format as mtimecmp, i.e. a full 64-bit unsigned value. - Section 2.2 mistakenly says that "instructions that access stimecmp when V==0 access vstimecmp instead". That should be for when V==1. - From M/S/HS/VS modes, access to stimecmp does not trap. But it does trap from U/VU modes. - From M/S/HS modes, access to vstimecmp does not trap. But it does trap from VS/U/VU modes. - Lastly, what section 4 asks for, I believe is already provided via hideleg bit 6. Greg
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