From: Luke Kenneth Casson Leighton Date: Tue, 25 Jun 2019 11:04:01 +0000 (+0100) Subject: clarify abridged spec X-Git-Tag: convert-csv-opcode-to-binary~4453 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=9c19f8f601dd60f280fd1f128a9a5e0eb44a3bc2;p=libreriscv.git clarify abridged spec --- diff --git a/simple_v_extension/abridged_spec.mdwn b/simple_v_extension/abridged_spec.mdwn index 5066624f2..9a70f0b7c 100644 --- a/simple_v_extension/abridged_spec.mdwn +++ b/simple_v_extension/abridged_spec.mdwn @@ -733,15 +733,8 @@ now looks like this: reg_t int_regfile[128]; -where when accessing any individual regfile[n].b entry it is permitted -(in c) to arbitrarily over-run the *declared* length of the array (zero), -and thus "overspill" to consecutive register file entries in a fashion -that is completely transparent to a greatly-simplified software / pseudo-code -representation. -It is however critical to note that it is clearly the responsibility of -the implementor to ensure that, towards the end of the register file, -an exception is thrown if attempts to access beyond the "real" register -bytes is ever attempted. +Implementors must ensure that over-runs of the register file throw +an exception. The pseudo-code is as follows, to demonstrate how the sign-extending and width-extending works: