From a1eac8e35163eccb0a00f03857a3e6ec8e88167d Mon Sep 17 00:00:00 2001 From: Mikael Pettersson Date: Sat, 11 Jul 2020 21:15:50 +0200 Subject: [PATCH] sim: sim_core.hrl: document that the status flags are sticky --- erlang/apps/sim/src/sim_core.hrl | 2 ++ 1 file changed, 2 insertions(+) diff --git a/erlang/apps/sim/src/sim_core.hrl b/erlang/apps/sim/src/sim_core.hrl index f24b066..98fae1e 100644 --- a/erlang/apps/sim/src/sim_core.hrl +++ b/erlang/apps/sim/src/sim_core.hrl @@ -72,6 +72,8 @@ -type word() :: uint36_t(). %%% Program Flags +%%% The Overflow, Carry 1/2, Floating Overflow, Floating Underflow, and No Divide +%%% flags are sticky: hardware sets them, but software must explicitly clear them. %%% Note: architecturally these occupy bits 0-12 (PDP10 bit numbering) of a %%% 36-bit word, but here we express them as occupying bits 12-0 (normal bit %%% numbering) of a 13-bit word. The bit numbers in the definitions are from