From: lkcl <lkcl@web>
Date: Fri, 29 Jan 2021 00:03:30 +0000 (+0000)
Subject: (no commit message)
X-Git-Tag: convert-csv-opcode-to-binary~260
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=217f61c3cb0f8be50bec4dee9f3c47db9b1eda10;p=libreriscv.git

---

diff --git a/openpower/sv/implementation.mdwn b/openpower/sv/implementation.mdwn
index b8a3491d0..88836a382 100644
--- a/openpower/sv/implementation.mdwn
+++ b/openpower/sv/implementation.mdwn
@@ -109,6 +109,10 @@ SV's SVSTATE context is effectively a Sub-PC.  On exceptions the PC is saved int
 
 main SV for-loop, as a FSM, updating `SVSTATE.srcstep`, using it as the index in the for-loop from 0 to VL-1.  Register numbers are incremented by one if marked as vector.
 
+*This loop goes in between decode and issue phases*.  It is as if there were multiple sequential instructions in the instruction stream *and the loop must be treated as such*.  Specifically: all register read and write hazards **MUST** be respected; the Program Order must be respected.
+
+This **includes** any exceptions, hence why SVSTATE exists and why SVSRR0 must be used to store SVSTATE alongside when SRR0 and SRR1 store PC and MSR.
+
 * ISACaller: TODO
 * power-gem5: TODO
 * TestIssuer: TODO