Clarify that misaligned accesses violating PMPs become partially visible

1 files changed, 11 insertions, 3 deletions

diff --git a/src/machine.tex b/src/machine.tex
index bf661ec..e03c349 100644
--- a/src/machine.tex
+++ b/src/machine.tex
@@ -2657,6 +2657,14 @@ Failed accesses generate a load, store, or instruction access exception.  Note
 that a single instruction may generate multiple accesses, which may not be
 mutually atomic.  An access exception is generated if at least one access
 generated by an instruction fails, though other accesses generated by that
-instruction may succeed with visible side effects.  In particular, misaligned
-loads, stores, and instruction fetches may be decomposed into multiple
-accesses, as will instructions that reference virtual memory.
+instruction may succeed with visible side effects.  In particular,
+instructions that reference virtual memory are decomposed into multiple
+accesses.
+
+On some implementations, misaligned loads, stores, and instruction fetches may
+also be decomposed into multiple accesses, some of which may succeed before an
+access exception is raised.  Notably, the portion of a misaligned store that
+passes the PMP check may become visible, even if another portion fails the PMP
+check.  The same behavior may manifest for floating-point stores wider than
+XLEN bits (e.g., the FSD instruction in RV32D), even when the store address is
+naturally aligned.