diff --git a/doc/ChangeLog.txt b/doc/ChangeLog.txt
index 89520094..c68c054c 100644
--- a/doc/ChangeLog.txt
+++ b/doc/ChangeLog.txt
@@ -7,6 +7,11 @@ The report_parasitics_annotation command reports SPEF annotation completeness.
 
   report_parasitics_annotation [-report_unannotated]
 
+The read_power_activities command reads a verilog vcd file and extracts
+pin activities for power analysis.
+
+  read_power_activities -vcd filename
+
 Release 2.3.3 2022/09/24
 -------------------------
 
diff --git a/doc/OpenSTA.odt b/doc/OpenSTA.odt
index fe4a1436..58cf047d 100644
Binary files a/doc/OpenSTA.odt and b/doc/OpenSTA.odt differ
diff --git a/doc/OpenSTA.pdf b/doc/OpenSTA.pdf
index c0f39f83..d22933d3 100644
Binary files a/doc/OpenSTA.pdf and b/doc/OpenSTA.pdf differ
diff --git a/power/Power.tcl b/power/Power.tcl
index bdd9ba42..c929a61a 100644
--- a/power/Power.tcl
+++ b/power/Power.tcl
@@ -31,7 +31,8 @@ define_cmd_args "report_power" \
 proc_redirect report_power {
   global sta_report_default_digits
 
-  parse_key_args "report_power" args keys {-instances -corner -digits} flags {} 1
+  parse_key_args "report_power" args \
+    keys {-instances -corner -digits} flags {}
 
   if { [info exists keys(-digits)] } {
     set digits $keys(-digits)
@@ -205,7 +206,7 @@ define_cmd_args "set_power_activity" { [-global]\
 proc set_power_activity { args } {
   parse_key_args "set_power_activity" args \
     keys {-input_ports -pins -activity -duty} \
-    flags {-global -input} 1
+    flags {-global -input}
 
   set activity 0.0
   if { [info exists keys(-activity)] } {
@@ -248,8 +249,18 @@ proc set_power_activity { args } {
 
 ################################################################
 
-# Defined in StaTcl.i
-define_cmd_args "read_vcd_activities" { filename }
+define_cmd_args "read_power_activities" { -vcd filename }
+
+proc read_power_activities { args } {
+  parse_key_args "read_power_activities" args \
+    keys {-vcd} flags {}
+
+  check_arg1 $args
+  set filename [file nativename [lindex $args 0]]
+  read_vcd_activities $filename
+}
+
+################################################################
 
 proc power_find_nan { } {
   set corner [cmd_corner]