From 04e9ffa2b2c607880631677654634bc4aa52882a Mon Sep 17 00:00:00 2001
From: Andrew Dennison <andrew@motec.com.au>
Date: Tue, 1 Jun 2021 09:48:02 +1000
Subject: [PATCH] soc/csr: Document simulation side effects of read/write

---
 litex/soc/interconnect/csr.py | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/litex/soc/interconnect/csr.py b/litex/soc/interconnect/csr.py
index ba4409bea..b9fc46e78 100644
--- a/litex/soc/interconnect/csr.py
+++ b/litex/soc/interconnect/csr.py
@@ -419,11 +419,16 @@ class CSRStorage(_CompoundCSR):
         self.sync += self.re.eq(sc.re)
 
     def read(self):
-        """Read method for simulation."""
+        """Read method for simulation.
+
+        Side effects: none (asynchronous)."""
         return (yield self.storage)
 
     def write(self, value):
-        """Write method for simulation."""
+        """Write method for simulation.
+
+        Side effects: synchronous advances simulation clk by one tick."""
+
         yield self.storage.eq(value)
         yield self.re.eq(1)
         if hasattr(self, "fields"):