From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Tue, 25 Jun 2019 13:53:27 +0000 (+0100)
Subject: explain gate saving
X-Git-Tag: convert-csv-opcode-to-binary~4426
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=606a6ec63a26b074706f11e18c610f67a418b842;p=libreriscv.git

explain gate saving
---

diff --git a/simple_v_extension/specification.mdwn b/simple_v_extension/specification.mdwn
index 79273a9b3..c4250a5cd 100644
--- a/simple_v_extension/specification.mdwn
+++ b/simple_v_extension/specification.mdwn
@@ -585,7 +585,10 @@ described above.
 
 The 16 bit Predication CSR Table is a key-value store, so
 implementation-wise it will be faster to turn the table around (maintain
-topologically equivalent state):
+topologically equivalent state).  Opportunities then exist to access
+registers in unary form instead of binary, saving gates and power by
+only activating "redirection" with a single AND gate, instead of
+multiple multi-bit XORs (a CAM):
 
 [[!inline raw="yes" pages="simple_v_extension/pred_table" ]]