4 files changed, 19 insertions, 3 deletions

diff --git a/src/hypervisor.adoc b/src/hypervisor.adoc
index 7f63f69..124afca 100644
--- a/src/hypervisor.adoc
+++ b/src/hypervisor.adoc
@@ -1755,11 +1755,14 @@ Virtual supervisor external interrupt +
 Machine external interrupt 
 |1 +
 1 +
+1 +
 1
 |12 +
-13-15 +
+13 +
+14-15 +
 ≥16
 |Supervisor guest external interrupt +
+_Reserved for counter-overflow interrupt_ +
 _Reserved_ +
 _Designated for platform use_
 |0 +
diff --git a/src/machine.adoc b/src/machine.adoc
index 5c323d9..12bc039 100644
--- a/src/machine.adoc
+++ b/src/machine.adoc
@@ -1677,10 +1677,16 @@ Supervisor external interrupt +
 _Reserved_ +
 Machine external interrupt 
 |1 +
+1 +
+1 +
 1
-|12-15 +
+|12 +
+13 +
+14-15 +
 ≥16
 |_Reserved_ +
+_Reserved for counter-overflow interrupt_ +
+_Reserved_ +
 _Designated for platform use_ 
 |0 +
 0 +
diff --git a/src/priv-preface.adoc b/src/priv-preface.adoc
index a300fbe..5509389 100644
--- a/src/priv-preface.adoc
+++ b/src/priv-preface.adoc
@@ -37,6 +37,7 @@ version 1.12:
 * Defined the `misa`.V field to reflect that the V extension has been
 implemented.
 * Defined the RV32-only `medelegh` and `hedelegh` CSRs.
+* Reserved interrupt 13 for forthcoming counter-overflow interrupt extension.
 * Specified synchronization requirements when changing the PBMTE fields
 in `menvcfg` and `henvcfg`.
 * Clarified that "platform- or custom-use" interrupts are actually
diff --git a/src/supervisor.adoc b/src/supervisor.adoc
index a860ce5..16b74d3 100644
--- a/src/supervisor.adoc
+++ b/src/supervisor.adoc
@@ -425,6 +425,8 @@ include::images/bytefield/scausereg.edn[]
 1 +
 1 +
 1 +
+1 +
+1 +
 1
 |0 +
 1 +
@@ -432,7 +434,9 @@ include::images/bytefield/scausereg.edn[]
 5 +
 6-8 +
 9 +
-10-15 +
+10-12 +
+13 +
+14-15 +
 ≥16
 |_Reserved_ +
 Supervisor software interrupt +
@@ -441,6 +445,8 @@ Supervisor timer interrupt +
 _Reserved_ +
 Supervisor external interrupt +
 _Reserved_ +
+_Reserved for counter-overflow interrupt_ +
+_Reserved_ +
 _Designated for platform use_ 
 
 |0 +