update 64-bit prefix format

diff --git a/simple_v_extension/sv_prefix_proposal.rst b/simple_v_extension/sv_prefix_proposal.rst
index 97f94c4f6ff541de4864610031afc9e675d3373f..2e66d4fcae85ae1ee04ae470528d95657e99aca7 100644 (file)
--- a/simple_v_extension/sv_prefix_proposal.rst
+++ b/simple_v_extension/sv_prefix_proposal.rst
@@ -161,7 +161,7 @@ now set to "0b0111111".
 
 The extra bit for src and dest registers provides the full range of
 up to 128 registers, when combined with the extra bit from the 48 bit
-prefix as well.
+prefix as well.  SVtyp encodes how (whether) to set VL and MAXVL.
 
 SVtyp field encoding
 ====================