diff --git a/src/execution-engine-spec/subsystems.adoc b/src/execution-engine-spec/subsystems.adoc
index dccfa7f..dd84c11 100644
--- a/src/execution-engine-spec/subsystems.adoc
+++ b/src/execution-engine-spec/subsystems.adoc
@@ -40,7 +40,7 @@ The {central-arch-name} allows up to 16 subystem identifiers. Not all of these i
 ===== sr0: Simulation Control
 
 The Simulation Control register is a register that is 32-bits wide. It is accessible in unprivileged and privileged modes.
-Writing to it is only possible when the _Execution Engine_ in which the software executes is being simulated. Real hardware should generate an *UnknownInstr* exception if it happens.
+Writing to it is only possible when the _Execution Engine_ in which the software executes is being simulated. Real hardware should generate an *PrivFault* exception if it happens.
 
 [source]
 ----
@@ -50,6 +50,9 @@ ssw ss3, r0, sr0, 0 <2>
 <1> Read the Simulation Control register.
 <2> Write in the Simulation Control register.
 
-The register contains the value 1 when under simulation and 0 otherwise.
-Writing any value to it while under simulation has the effect of ending the simulation.
+The register contains the value 1 if under simulation and 0 otherwise. +
+Writing a value to it while under simulation has the effect of ending the simulation:
+
+* Writing 0 ends the simulation normaly
+* Writing any other value ends the simulation with an error
 
diff --git a/src/execution-engine-spec/system-behavior.adoc b/src/execution-engine-spec/system-behavior.adoc
index 323f7e7..560f49f 100644
--- a/src/execution-engine-spec/system-behavior.adoc
+++ b/src/execution-engine-spec/system-behavior.adoc
@@ -18,11 +18,11 @@ The _Execution Engine_ starts execution in Supervisor mode.
 |N/A
 
 |pc_user, pc_fault
-|0x0000_0004
+|0x0000_0000
 |#TODO: Describe it#
 
 |pc_svc
-|0x0000_0000
+|0x0000_0004
 |#TODO: Describe it#
 
 |psr