diff --git a/vpi/sys_display.c b/vpi/sys_display.c
index e92ca15b6..c291d00e3 100644
--- a/vpi/sys_display.c
+++ b/vpi/sys_display.c
@@ -1122,6 +1122,7 @@ static PLI_INT32 sys_monitor_calltf(PLI_BYTE8*name)
 		case vpiReg:
 		case vpiIntegerVar:
 		case vpiRealVar:
+		case vpiMemoryWord:
 		    /* Monitoring reg and net values involves setting
 		       a callback for value changes. Pass the storage
 		       pointer for the callback itself as user_data so
diff --git a/vvp/array.cc b/vvp/array.cc
index 8341c218c..3593bbda5 100644
--- a/vvp/array.cc
+++ b/vvp/array.cc
@@ -63,6 +63,7 @@ struct __vpiArray {
       struct __vpiArrayWord*vals_words;
 
       class vvp_fun_arrayport*ports_;
+      struct __vpiCallback *vpi_callbacks;
 };
 
 struct __vpiArrayIterator {
@@ -192,11 +193,25 @@ static const struct __vpirt vpip_array_vthr_A_rt = {
 # define ARRAY_HANDLE(ref) (assert(ref->vpi_type->type_code==vpiMemory), \
 			    (struct __vpiArray*)ref)
 
-# define ARRAY_VAR_WORD(ref) (assert(ref->vpi_type->type_code==vpiMemoryWord), \
-			      (struct __vpiArrayWord*)ref)
+static struct __vpiArrayWord* array_var_word_from_handle(vpiHandle ref)
+{
+      if (ref == 0)
+	    return 0;
+      if (ref->vpi_type != &vpip_array_var_word_rt)
+	    return 0;
 
-# define ARRAY_VTHR_A_HANDLE(ref) (assert(ref->vpi_type->type_code==vpiMemoryWord), \
-			    (struct __vpiArrayVthrA*)ref)
+      return (struct __vpiArrayWord*) ref;
+}
+
+static struct __vpiArrayVthrA* array_vthr_a_from_handle(vpiHandle ref)
+{
+      if (ref == 0)
+	    return 0;
+      if (ref->vpi_type != &vpip_array_vthr_A_rt)
+	    return 0;
+
+      return (struct __vpiArrayVthrA*) ref;
+}
 
 static void array_make_vals_words(struct __vpiArray*parent)
 {
@@ -315,9 +330,10 @@ static vpiHandle vpi_array_index(vpiHandle ref, int index)
 
 static int vpi_array_var_word_get(int code, vpiHandle ref)
 {
-      struct __vpiArrayWord*obj = ARRAY_VAR_WORD(ref);
+      struct __vpiArrayWord*obj = array_var_word_from_handle(ref);
       struct __vpiArray*parent;
 
+      assert(obj);
       decode_array_word_pointer(obj, parent);
 
       switch (code) {
@@ -331,9 +347,10 @@ static int vpi_array_var_word_get(int code, vpiHandle ref)
 
 static void vpi_array_var_word_get_value(vpiHandle ref, p_vpi_value value)
 {
-      struct __vpiArrayWord*obj = ARRAY_VAR_WORD(ref);
+      struct __vpiArrayWord*obj = array_var_word_from_handle(ref);
       struct __vpiArray*parent;
 
+      assert(obj);
       unsigned index = decode_array_word_pointer(obj, parent);
 
       vpip_vec4_get_value(parent->vals[index], parent->vals_width,
@@ -342,9 +359,10 @@ static void vpi_array_var_word_get_value(vpiHandle ref, p_vpi_value value)
 
 static vpiHandle vpi_array_var_word_put_value(vpiHandle ref, p_vpi_value vp, int flags)
 {
-      struct __vpiArrayWord*obj = ARRAY_VAR_WORD(ref);
+      struct __vpiArrayWord*obj = array_var_word_from_handle(ref);
       struct __vpiArray*parent;
 
+      assert(obj);
       unsigned index = decode_array_word_pointer(obj, parent);
 
       vvp_vector4_t val = vec4_from_vpi_value(vp, parent->vals_width);
@@ -426,7 +444,8 @@ static int array_index_free_object(vpiHandle ref)
 
 static int vpi_array_vthr_A_get(int code, vpiHandle ref)
 {
-      struct __vpiArrayVthrA*obj = ARRAY_VTHR_A_HANDLE(ref);
+      struct __vpiArrayVthrA*obj = array_vthr_a_from_handle(ref);
+      assert(obj);
       struct __vpiArray*parent = obj->array;
 
       switch (code) {
@@ -443,7 +462,8 @@ static int vpi_array_vthr_A_get(int code, vpiHandle ref)
 }
 static void vpi_array_vthr_A_get_value(vpiHandle ref, p_vpi_value value)
 {
-      struct __vpiArrayVthrA*obj = ARRAY_VTHR_A_HANDLE(ref);
+      struct __vpiArrayVthrA*obj = array_vthr_a_from_handle(ref);
+      assert(obj);
       struct __vpiArray*parent = obj->array;
 
       assert(parent);
@@ -456,7 +476,8 @@ static void vpi_array_vthr_A_get_value(vpiHandle ref, p_vpi_value value)
 
 static vpiHandle vpi_array_vthr_A_put_value(vpiHandle ref, p_vpi_value vp, int)
 {
-      struct __vpiArrayVthrA*obj = ARRAY_VTHR_A_HANDLE(ref);
+      struct __vpiArrayVthrA*obj = array_vthr_a_from_handle(ref);
+      assert(obj);
       struct __vpiArray*parent = obj->array;
 
       unsigned index = obj->address;
@@ -579,6 +600,7 @@ static vpiHandle vpip_make_array(char*label, const char*name,
 
 	// Initialize (clear) the read-ports list.
       obj->ports_ = 0;
+      obj->vpi_callbacks = 0;
 
 	/* Add this symbol to the array_symbols table for later lookup. */
       if (!array_table)
@@ -745,6 +767,42 @@ void array_word_change(vvp_array_t array, unsigned long addr)
 {
       for (vvp_fun_arrayport*cur = array->ports_; cur; cur = cur->next_)
 	    cur->check_word_change(addr);
+
+	// Run callbacks attatched to the array itself.
+      struct __vpiCallback *next = array->vpi_callbacks;
+      struct __vpiCallback *prev = 0;
+
+      while (next) {
+	    struct __vpiCallback*cur = next;
+	    next = cur->next;
+
+	      // Skip callbacks for callbacks not for me.
+	    if (cur->extra_data != (long)addr) {
+		  prev = cur;
+		  continue;
+	    }
+
+	    if (cur->cb_data.cb_rtn != 0) {
+		  if (cur->cb_data.value)
+			vpip_vec4_get_value(array->vals[addr], array->vals_width,
+					    false, cur->cb_data.value);
+
+		  callback_execute(cur);
+		  prev = cur;
+
+	    } else if (prev == 0) {
+
+		  array->vpi_callbacks = next;
+		  cur->next = 0;
+		  delete_vpi_callback(cur);
+
+	    } else {
+		  assert(prev->next == cur);
+		  prev->next = next;
+		  cur->next = 0;
+		  delete_vpi_callback(cur);
+	    }
+      }
 }
 
 class array_port_resolv_list_t : public resolv_list_s {
@@ -780,6 +838,23 @@ bool array_port_resolv_list_t::resolve(bool mes)
       return true;
 }
 
+void vpip_array_word_change(struct __vpiCallback*cb, vpiHandle obj)
+{
+      struct __vpiArray*parent = 0;
+      if (struct __vpiArrayWord*word = array_var_word_from_handle(obj)) {
+	    unsigned addr = decode_array_word_pointer(word, parent);
+	    cb->extra_data = addr;
+
+      } else if (struct __vpiArrayVthrA*word = array_vthr_a_from_handle(obj)) {
+	    parent = word->array;
+	    cb->extra_data = word->address;
+      }
+
+      assert(parent);
+      cb->next = parent->vpi_callbacks;
+      parent->vpi_callbacks = cb;
+}
+
 void compile_array_port(char*label, char*array, char*addr)
 {
       array_port_resolv_list_t*resolv_mem
diff --git a/vvp/array.h b/vvp/array.h
index c081a4eb6..e67832761 100644
--- a/vvp/array.h
+++ b/vvp/array.h
@@ -45,6 +45,11 @@ extern void array_set_word(vvp_array_t arr,
 
 extern vvp_vector4_t array_get_word(vvp_array_t array, unsigned adddress);
 
+/* VPI hooks */
+
+extern void vpip_array_word_change(struct __vpiCallback*cb, vpiHandle word);
+
+/* Compile hooks */
 extern void compile_variablew(char*label, vvp_array_t array,
 			      unsigned long array_addr,
 			     int msb, int lsb, char signed_flag);
diff --git a/vvp/vpi_callback.cc b/vvp/vpi_callback.cc
index 2348d9e65..6313c3896 100644
--- a/vvp/vpi_callback.cc
+++ b/vvp/vpi_callback.cc
@@ -103,7 +103,7 @@ struct __vpiCallback* new_vpi_callback()
       return obj;
 }
 
-static void delete_vpi_callback(struct __vpiCallback* ref)
+void delete_vpi_callback(struct __vpiCallback* ref)
 {
       assert(ref);
       assert(ref->base.vpi_type);
@@ -162,6 +162,10 @@ static struct __vpiCallback* make_value_change(p_cb_data data)
 	    nev->callbacks = obj;
 	    break;
 
+	  case vpiMemoryWord:
+	    vpip_array_word_change(obj, data->obj);
+	    break;
+
 	  case vpiModule:
 	  case vpiConstant:
 	  case vpiParameter:
@@ -461,14 +465,11 @@ void callback_execute(struct __vpiCallback*cur)
 vvp_vpi_callback::vvp_vpi_callback()
 {
       vpi_callbacks_ = 0;
-      array_ = 0;
-      array_word_ = 0;
 }
 
 vvp_vpi_callback::~vvp_vpi_callback()
 {
       assert(vpi_callbacks_ == 0);
-      assert(array_ == 0);
 }
 
 void vvp_vpi_callback::add_vpi_callback(__vpiCallback*cb)
@@ -477,13 +478,6 @@ void vvp_vpi_callback::add_vpi_callback(__vpiCallback*cb)
       vpi_callbacks_ = cb;
 }
 
-void vvp_vpi_callback::attach_as_word(vvp_array_t arr, unsigned long addr)
-{
-      assert(array_ == 0);
-      array_ = arr;
-      array_word_ = addr;
-}
-
 /*
  * A vvp_fun_signal uses this method to run its callbacks whenever it
  * has a value change. If the cb_rtn is non-nil, then call the
@@ -495,8 +489,6 @@ void vvp_vpi_callback::run_vpi_callbacks()
       struct __vpiCallback *next = vpi_callbacks_;
       struct __vpiCallback *prev = 0;
 
-      if (array_) array_word_change(array_, array_word_);
-
       while (next) {
 	    struct __vpiCallback*cur = next;
 	    next = cur->next;
@@ -523,6 +515,31 @@ void vvp_vpi_callback::run_vpi_callbacks()
       }
 }
 
+vvp_vpi_callback_wordable::vvp_vpi_callback_wordable()
+{
+      array_ = 0;
+      array_word_ = 0;
+}
+
+vvp_vpi_callback_wordable::~vvp_vpi_callback_wordable()
+{
+      assert(array_ == 0);
+}
+
+void vvp_vpi_callback_wordable::run_vpi_callbacks()
+{
+      if (array_) array_word_change(array_, array_word_);
+
+      vvp_vpi_callback::run_vpi_callbacks();
+}
+
+void vvp_vpi_callback_wordable::attach_as_word(vvp_array_t arr, unsigned long addr)
+{
+      assert(array_ == 0);
+      array_ = arr;
+      array_word_ = addr;
+}
+
 void vvp_fun_signal::get_value(struct t_vpi_value*vp)
 {
       switch (vp->format) {
diff --git a/vvp/vpi_priv.h b/vvp/vpi_priv.h
index 77e685e36..fc43caeff 100644
--- a/vvp/vpi_priv.h
+++ b/vvp/vpi_priv.h
@@ -141,11 +141,15 @@ struct __vpiCallback {
 	// scheduled event
       struct sync_cb* cb_sync;
 
+	// The calback holder may use this for various purposes.
+      long extra_data;
+
 	// Used for listing callbacks.
       struct __vpiCallback*next;
 };
 
 extern struct __vpiCallback* new_vpi_callback();
+extern void delete_vpi_callback(struct __vpiCallback* ref);
 extern void callback_execute(struct __vpiCallback*cur);
 
 struct __vpiSystemTime {
diff --git a/vvp/vvp_net.h b/vvp/vvp_net.h
index bcf2638c7..db99205a2 100644
--- a/vvp/vvp_net.h
+++ b/vvp/vvp_net.h
@@ -882,20 +882,29 @@ class vvp_vpi_callback {
       vvp_vpi_callback();
       virtual ~vvp_vpi_callback();
 
-      void run_vpi_callbacks();
+      virtual void run_vpi_callbacks();
       void add_vpi_callback(struct __vpiCallback*);
 
       virtual void get_value(struct t_vpi_value*value) =0;
 
+    private:
+      struct __vpiCallback*vpi_callbacks_;
+};
+
+class vvp_vpi_callback_wordable : public vvp_vpi_callback {
+    public:
+      vvp_vpi_callback_wordable();
+      ~vvp_vpi_callback_wordable();
+
+      void run_vpi_callbacks();
       void attach_as_word(class __vpiArray* arr, unsigned long addr);
 
     private:
-      struct __vpiCallback*vpi_callbacks_;
       class __vpiArray* array_;
       unsigned long array_word_;
 };
 
-class vvp_fun_signal_base : public vvp_net_fun_t, public vvp_vpi_callback {
+class vvp_fun_signal_base : public vvp_net_fun_t, public vvp_vpi_callback_wordable {
 
     public:
       vvp_fun_signal_base();