diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3a6d588..6fa3d9b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -35,7 +35,7 @@ FILE(GLOB TGC_VM_SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/src/vm/interp/vm_*.cpp)
 set(LIB_SOURCES 
     src/vm/fp_functions.cpp
     src/plugin/instruction_count.cpp
-    src/plugin/cov.cpp
+    src/plugin/pctrace.cpp
     
     ${TGC_SOURCES}
     ${TGC_VM_SOURCES}
diff --git a/incl/iss/plugin/cov.h b/incl/iss/plugin/pctrace.h
similarity index 83%
rename from incl/iss/plugin/cov.h
rename to incl/iss/plugin/pctrace.h
index 1f0c9bd..0cad8b0 100644
--- a/incl/iss/plugin/cov.h
+++ b/incl/iss/plugin/pctrace.h
@@ -52,6 +52,18 @@ class cov : public iss::vm_plugin {
         size_t not_taken_delay;
         size_t taken_delay;
     };
+    BEGIN_BF_DECL(instr_desc, uint32_t)
+        BF_FIELD(taken, 24, 8)
+        BF_FIELD(not_taken, 16, 8)
+        BF_FIELD(is_branch, 8, 8)
+        BF_FIELD(size, 0, 8)
+        instr_desc(uint32_t size, uint32_t taken, uint32_t not_taken, bool branch): instr_desc() {
+            this->size=size;
+            this->taken=taken;
+            this->not_taken=not_taken;
+            this->is_branch=branch;
+        }
+    END_BF_DECL();
 
 public:
 
@@ -59,7 +71,7 @@ public:
 
     cov(const cov &&) = delete;
 
-    cov();
+    cov(std::string const &);
 
     virtual ~cov();
 
@@ -75,8 +87,10 @@ public:
 
 private:
     iss::instrumentation_if *instr_if  {nullptr};
-    int counter {0};
     std::ofstream output;
+    std::string filename;
+    std::vector<instr_desc> delays;
+
 };
 }
 }
diff --git a/src/plugin/cov.cpp b/src/plugin/cov.cpp
deleted file mode 100644
index 46b1d32..0000000
--- a/src/plugin/cov.cpp
+++ /dev/null
@@ -1,32 +0,0 @@
-#include <iss/plugin/cov.h>
-#include <iss/arch_if.h>
-#include <iostream>
-
-
-iss::plugin::cov::cov() {
-    std::cout << "Entering Constructor"<<std::endl;
-    output.open("output.txt");
-
-}
-
-iss::plugin::cov::~cov() {
-    std::cout << "Entering Destructor"<<std::endl;
-    output.close();
-
-
-}
-
-bool iss::plugin::cov::registration(const char *const version, vm_if& vm) {
-    instr_if = vm.get_arch()->get_instrumentation_if();
-    return true;
-}
-void iss::plugin::cov::callback(instr_info_t iinfo, const exec_info&) {
-//    if((instr_if->get_next_pc() - instr_if->get_pc() != 4) ||( instr_if->get_next_pc() - instr_if->get_pc() != 2)){
-//        std::cout << "jump from " << std::hex << instr_if->get_pc() << " to " << instr_if->get_next_pc()<< " after " << std::dec << counter <<" linear instructions" <<std::endl;
-//        counter = 0;
-//    }else {
-//        counter++;
-//    }
-
-    output<<std::hex << instr_if->get_pc() << std::endl;
-}
diff --git a/src/plugin/cycle_estimate.cpp b/src/plugin/cycle_estimate.cpp
index 88e275a..f68d241 100644
--- a/src/plugin/cycle_estimate.cpp
+++ b/src/plugin/cycle_estimate.cpp
@@ -85,7 +85,7 @@ bool iss::plugin::cycle_estimate::registration(const char* const version, vm_if&
                                 delays.push_back(instr_desc{size.Get<unsigned>(), d, d, branch.Get<bool>()});
                             } else
                                 throw runtime_error("JSON parse error");
-                        }
+                       }
                     } else {
                         LOG(ERR)<<"plugin cycle_estimate: could not find an entry for "<<core_name<<" in JSON file"<<endl;
                         return false;
@@ -111,7 +111,7 @@ void iss::plugin::cycle_estimate::callback(instr_info_t instr_info, exec_info co
     assert(arch_instr && "No instrumentation interface available but callback executed");
     auto entry = delays[instr_info.instr_id];
     bool taken = exc_info.branch_taken;
-    if (exc_info.branch_taken && entry.taken > 1)
+    if (exc_info.branch_taken && (entry.taken > 1))
         arch_instr->set_curr_instr_cycles(entry.taken);
     else if (entry.not_taken > 1)
         arch_instr->set_curr_instr_cycles(entry.not_taken);
diff --git a/src/plugin/pctrace.cpp b/src/plugin/pctrace.cpp
new file mode 100644
index 0000000..1a92dd4
--- /dev/null
+++ b/src/plugin/pctrace.cpp
@@ -0,0 +1,97 @@
+#include <iss/arch_if.h>
+#include <iss/plugin/pctrace.h>
+#include <util/logging.h>
+#include <rapidjson/document.h>
+#include <rapidjson/istreamwrapper.h>
+#include "rapidjson/writer.h"
+#include "rapidjson/stringbuffer.h"
+#include <rapidjson/ostreamwrapper.h>
+#include <rapidjson/error/en.h>
+#include <fstream>
+
+#include <iostream>
+
+
+using namespace rapidjson;
+using namespace std;
+
+iss::plugin::cov::cov(std::string const &filename)
+    : instr_if(nullptr)
+    , filename(filename)
+{
+    output.open("output.trc");
+}
+
+iss::plugin::cov::~cov() {
+    output.close();
+}
+
+bool iss::plugin::cov::registration(const char *const version, vm_if& vm) {
+    instr_if = vm.get_arch()->get_instrumentation_if();
+    if(!instr_if) return false;
+    const string  core_name = instr_if->core_type_name();
+    if (filename.length() > 0) {
+        ifstream is(filename);
+        if (is.is_open()) {
+            try {
+                IStreamWrapper isw(is);
+                Document d;
+                ParseResult ok = d.ParseStream(isw);
+                if(ok) {
+                    Value& val = d[core_name.c_str()];
+                    if(val.IsArray()){
+                        delays.reserve(val.Size());
+                        for (auto it = val.Begin(); it != val.End(); ++it) {
+                            auto& name = (*it)["name"];
+                            auto& size = (*it)["size"];
+                            auto& delay = (*it)["delay"];
+                            auto& branch = (*it)["branch"];
+                            if(delay.IsArray()) {
+                                auto dt = delay[0].Get<unsigned>();
+                                auto dnt = delay[1].Get<unsigned>();
+                                delays.push_back(instr_desc{size.Get<unsigned>(), dt, dnt, branch.Get<bool>()});
+                            } else if(delay.Is<unsigned>()) {
+                                auto d = delay.Get<unsigned>();
+                                delays.push_back(instr_desc{size.Get<unsigned>(), d, d, branch.Get<bool>()});
+                            } else
+                                throw runtime_error("JSON parse error");
+
+                        }
+                    } else {
+                        LOG(ERR)<<"plugin cycle_estimate: could not find an entry for "<<core_name<<" in JSON file"<<endl;
+                        return false;
+                   }
+                } else {
+                    LOG(ERR)<<"plugin cycle_estimate: could not parse in JSON file at "<< ok.Offset()<<": "<<GetParseError_En(ok.Code())<<endl;
+                    return false;
+               }
+            } catch (runtime_error &e) {
+                LOG(ERR) << "Could not parse input file " << filename << ", reason: " << e.what();
+                return false;
+            }
+        } else {
+            LOG(ERR) << "Could not open input file " << filename;
+            return false;
+        }
+    }
+    return true;
+
+
+
+}
+void iss::plugin::cov::callback(instr_info_t iinfo, const exec_info& einfo) {
+//    if((instr_if->get_next_pc() - instr_if->get_pc() != 4) ||( instr_if->get_next_pc() - instr_if->get_pc() != 2)){
+//        std::cout << "jump from " << std::hex << instr_if->get_pc() << " to " << instr_if->get_next_pc()<< " after " << std::dec << counter <<" linear instructions" <<std::endl;
+//        counter = 0;
+//    }else {
+//        counter++;
+//    }
+    auto delay = 0;
+    auto entry = delays[iinfo.instr_id];
+    bool taken = einfo.branch_taken;
+    if (einfo.branch_taken)
+        delay = entry.taken;
+    else
+       delay = entry.not_taken;
+    output<<std::hex <<"0x" << instr_if->get_pc() <<"," << delay << "\n";
+}
diff --git a/src/sysc/core_complex.cpp b/src/sysc/core_complex.cpp
index 8ec288d..23ab3e5 100644
--- a/src/sysc/core_complex.cpp
+++ b/src/sysc/core_complex.cpp
@@ -69,7 +69,7 @@ using tgc_d_xrb_nn_plat_type = iss::arch::riscv_hart_mu_p<iss::arch::tgc_d_xrb_n
 #include <array>
 #include <iss/plugin/cycle_estimate.h>
 #include <iss/plugin/instruction_count.h>
-#include <iss/plugin/cov.h>
+#include <iss/plugin/pctrace.h>
 
 // clang-format on
 
@@ -426,8 +426,8 @@ void core_complex::before_end_of_elaboration() {
                 auto *plugin = new iss::plugin::cycle_estimate(filename);
                 cpu->vm->register_plugin(*plugin);
                 plugin_list.push_back(plugin);
-            } else if (plugin_name == "cov") {
-                auto *plugin = new iss::plugin::cov();
+            } else if (plugin_name == "pctrace") {
+                auto *plugin = new iss::plugin::cov(filename);
                 cpu->vm->register_plugin(*plugin);
                 plugin_list.push_back(plugin);
             } else {