diff --git a/CMakeLists.txt b/CMakeLists.txt
index 00946f1..1cc93ac 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -365,6 +365,7 @@ set(VR4300_SOURCES
   ${PROJECT_SOURCE_DIR}/vr4300/cpu.c
   ${PROJECT_SOURCE_DIR}/vr4300/dcache.c
   ${PROJECT_SOURCE_DIR}/vr4300/decoder.c
+  ${PROJECT_SOURCE_DIR}/vr4300/debug.c
   ${PROJECT_SOURCE_DIR}/vr4300/fault.c
   ${PROJECT_SOURCE_DIR}/vr4300/functions.c
   ${PROJECT_SOURCE_DIR}/vr4300/icache.c
diff --git a/bus/controller.h b/bus/controller.h
index e7ed702..956d745 100644
--- a/bus/controller.h
+++ b/bus/controller.h
@@ -55,11 +55,5 @@ cen64_flatten cen64_hot int bus_read_word(const struct bus_controller *bus,
 cen64_flatten cen64_hot int bus_write_word(struct bus_controller *bus,
   uint32_t address, uint32_t word, uint32_t dqm);
 
-// For asserting and deasserting RCP interrupts.
-enum rcp_interrupt_mask;
-
-int raise_rcp_interrupt(struct bus_controller *bus,
-  enum rcp_interrupt_mask mask);
-
 #endif
 
diff --git a/device/device.c b/device/device.c
index 89924e8..cd5a046 100644
--- a/device/device.c
+++ b/device/device.c
@@ -349,3 +349,6 @@ int device_debug_spin(struct cen64_device *device) {
   return 0;
 }
 
+cen64_cold void device_connect_debugger(struct cen64_device *device, void* break_handler_data, vr4300_debug_break_handler break_handler) {
+  vr4300_connect_debugger(device->vr4300, break_handler_data, break_handler);
+}
\ No newline at end of file
diff --git a/device/device.h b/device/device.h
index 34003bc..81709c2 100644
--- a/device/device.h
+++ b/device/device.h
@@ -67,5 +67,7 @@ cen64_cold struct cen64_device *device_create(struct cen64_device *device,
 cen64_cold void device_exit(struct bus_controller *bus);
 cen64_cold void device_run(struct cen64_device *device);
 
+cen64_cold void device_connect_debugger(struct cen64_device *device, void* break_handler_data, vr4300_debug_break_handler break_handler);
+
 #endif
 
diff --git a/vr4300/cpu.c b/vr4300/cpu.c
index 81a269a..c238ec1 100644
--- a/vr4300/cpu.c
+++ b/vr4300/cpu.c
@@ -70,6 +70,8 @@ int vr4300_init(struct vr4300 *vr4300, struct bus_controller *bus, bool profilin
   else
     vr4300->profile_samples = NULL;
 
+  vr4300_debug_init(&vr4300->debug);
+
   return 0;
 }
 
@@ -126,11 +128,23 @@ void vr4300_print_summary(struct vr4300_stats *stats) {
 }
 
 uint64_t vr4300_get_register(struct vr4300 *vr4300, size_t i) {
-    return vr4300->regs[i];
+  return vr4300->regs[i];
 }
 
 uint64_t vr4300_get_pc(struct vr4300 *vr4300) {
-    return vr4300->pipeline.dcwb_latch.common.pc;
+  return vr4300->pipeline.dcwb_latch.common.pc;
+}
+
+cen64_cold void vr4300_signal_break(struct vr4300 *vr4300) {
+  vr4300_debug_signal(&vr4300->debug, VR4300_DEBUG_SIGNALS_BREAK);
+}
+
+cen64_cold void vr4300_set_breakpoint(struct vr4300 *vr4300, uint64_t at) {
+  vr4300_debug_set_breakpoint(&vr4300->debug, at);
+}
+
+cen64_cold void vr4300_remove_breakpoint(struct vr4300 *vr4300, uint64_t at) {
+  vr4300_debug_remove_breakpoint(&vr4300->debug, at);
 }
 
 struct vr4300* vr4300_alloc() {
@@ -140,6 +154,7 @@ struct vr4300* vr4300_alloc() {
 }
 
 cen64_cold void vr4300_free(struct vr4300* ptr) {
+    vr4300_debug_cleanup(&ptr->debug);
     free(ptr);
 }
 
@@ -152,3 +167,8 @@ cen64_cold struct vr4300_stats* vr4300_stats_alloc() {
 cen64_cold void vr4300_stats_free(struct vr4300_stats* ptr) {
     free(ptr);
 }
+
+cen64_cold void vr4300_connect_debugger(struct vr4300 *vr4300, void* break_handler_data, vr4300_debug_break_handler break_handler) {
+  vr4300->debug.break_handler = break_handler;
+  vr4300->debug.break_handler_data = break_handler_data;
+}
\ No newline at end of file
diff --git a/vr4300/cpu.h b/vr4300/cpu.h
index 53b73b5..423a29a 100644
--- a/vr4300/cpu.h
+++ b/vr4300/cpu.h
@@ -14,7 +14,9 @@
 #include "vr4300/cp0.h"
 #include "vr4300/cp1.h"
 #include "vr4300/dcache.h"
+#include "vr4300/debug.h"
 #include "vr4300/icache.h"
+#include "vr4300/interface.h"
 #include "vr4300/opcodes.h"
 #include "vr4300/pipeline.h"
 
@@ -23,6 +25,7 @@ struct bus_controller;
 enum vr4300_signals {
   VR4300_SIGNAL_FORCEEXIT = 0x000000001,
   VR4300_SIGNAL_COLDRESET = 0x000000002,
+  VR4300_SIGNAL_BREAK = 0x000000004,
 };
 
 enum vr4300_register {
@@ -103,6 +106,8 @@ struct vr4300 {
   struct vr4300_icache icache;
 
   uint64_t *profile_samples;
+
+  struct vr4300_debug debug;
 };
 
 struct vr4300_stats {
@@ -112,7 +117,6 @@ struct vr4300_stats {
   unsigned long opcode_counts[NUM_VR4300_OPCODES];
 };
 
-cen64_cold int vr4300_init(struct vr4300 *vr4300, struct bus_controller *bus, bool profiling);
 cen64_cold void vr4300_print_summary(struct vr4300_stats *stats);
 
 cen64_flatten cen64_hot void vr4300_cycle_(struct vr4300 *vr4300);
diff --git a/vr4300/debug.c b/vr4300/debug.c
new file mode 100644
index 0000000..19f2ace
--- /dev/null
+++ b/vr4300/debug.c
@@ -0,0 +1,55 @@
+//
+// vr4300/debug.c: VR4300 debug hooks.
+//
+// CEN64: Cycle-Accurate Nintendo 64 Emulator.
+// Copyright (C) 2015, Tyler J. Stachecki.
+//
+// This file is subject to the terms and conditions defined in
+// 'LICENSE', which is part of this source code package.
+//
+
+#include "debug.h"
+
+cen64_cold void vr4300_debug_init(struct vr4300_debug* debug) {
+  hash_table_init(&debug->breakpoints, 0);
+  debug->break_handler = NULL;
+  debug->break_handler_data = NULL;
+}
+
+cen64_cold void vr4300_debug_cleanup(struct vr4300_debug* debug) {
+  hash_table_free(&debug->breakpoints);
+}
+
+cen64_cold void vr4300_debug_check_breakpoints(struct vr4300_debug* debug, uint64_t pc) {
+  if (debug->break_handler) {
+    enum vr4300_debug_break_reason reason = VR4300_DEBUG_BREAK_REASON_NONE;
+    if (hash_table_get(&debug->breakpoints, (unsigned long)pc, NULL)) {
+      reason = VR4300_DEBUG_BREAK_REASON_BREAKPOINT;
+    } else if (debug->signals & VR4300_DEBUG_SIGNALS_BREAK) {
+      reason = VR4300_DEBUG_BREAK_REASON_PAUSE;
+    }
+    
+    if (reason != VR4300_DEBUG_BREAK_REASON_NONE) {
+      debug->signals &= ~VR4300_DEBUG_SIGNALS_BREAK;
+      debug->break_handler(debug->break_handler_data, reason);
+    }
+  }
+}
+
+cen64_cold void vr4300_debug_exception(struct vr4300_debug* debug) {
+  if (debug->break_handler) {
+    debug->break_handler(debug->break_handler_data, VR4300_DEBUG_BREAK_REASON_EXCEPTION);
+  }
+}
+
+cen64_cold void vr4300_debug_set_breakpoint(struct vr4300_debug* debug, uint64_t pc) {
+  hash_table_set(&debug->breakpoints, (unsigned long)pc, 1);
+}
+
+cen64_cold void vr4300_debug_remove_breakpoint(struct vr4300_debug* debug, uint64_t pc) {
+  hash_table_delete(&debug->breakpoints, (unsigned long)pc);
+}
+
+cen64_cold void vr4300_debug_signal(struct vr4300_debug* debug, enum vr4300_debug_signals signal) {
+  debug->signals |= signal;
+}
\ No newline at end of file
diff --git a/vr4300/debug.h b/vr4300/debug.h
new file mode 100644
index 0000000..f4a613c
--- /dev/null
+++ b/vr4300/debug.h
@@ -0,0 +1,38 @@
+//
+// vr4300/debug.h: VR4300 debug hooks.
+//
+// CEN64: Cycle-Accurate Nintendo 64 Emulator.
+// Copyright (C) 2015, Tyler J. Stachecki.
+//
+// This file is subject to the terms and conditions defined in
+// 'LICENSE', which is part of this source code package.
+//
+
+#ifndef __vr4300_debug_h__
+#define __vr4300_debug_h__
+#include "common.h"
+#include "common/hash_table.h"
+#include "vr4300/interface.h"
+
+enum vr4300_debug_signals {
+  VR4300_DEBUG_SIGNALS_BREAK  = 0x000000001,
+};
+
+struct vr4300_debug {
+    struct hash_table breakpoints;
+    vr4300_debug_break_handler break_handler;
+    void* break_handler_data;
+    unsigned signals;
+};
+
+cen64_cold void vr4300_debug_init(struct vr4300_debug* debug);
+
+cen64_cold void vr4300_debug_cleanup(struct vr4300_debug* debug);
+cen64_cold void vr4300_debug_check_breakpoints(struct vr4300_debug* debug, uint64_t pc);
+cen64_cold void vr4300_debug_exception(struct vr4300_debug* debug);
+cen64_cold void vr4300_debug_set_breakpoint(struct vr4300_debug* debug, uint64_t pc);
+cen64_cold void vr4300_debug_remove_breakpoint(struct vr4300_debug* debug, uint64_t pc);
+
+cen64_cold void vr4300_debug_signal(struct vr4300_debug* debug, enum vr4300_debug_signals signal);
+
+#endif
\ No newline at end of file
diff --git a/vr4300/fault.c b/vr4300/fault.c
index 70c0e51..072710a 100644
--- a/vr4300/fault.c
+++ b/vr4300/fault.c
@@ -483,6 +483,7 @@ void VR4300_BRPT(struct vr4300 *vr4300) {
   vr4300_exception_prolog(vr4300, common, &cause, &status, &epc);
   vr4300_exception_epilogue(vr4300, (cause & ~0xFF) | (9 << 2),
     status, epc, 0x180);
+  vr4300_debug_exception(&vr4300->debug);
 }
 
 // TRAP: Trap exception
@@ -495,6 +496,7 @@ void VR4300_TRAP(struct vr4300* vr4300) {
   vr4300_exception_prolog(vr4300, common, &cause, &status, &epc);
   vr4300_exception_epilogue(vr4300, (cause & ~0xFF) | (13 << 2),
     status, epc, 0x180);
+  vr4300_debug_exception(&vr4300->debug);
 }
 
 // RI: Reserved Instruction exception
@@ -521,5 +523,6 @@ void VR4300_WAT(struct vr4300 *vr4300) {
     status, epc, 0x180);
 
   vr4300_dc_fault(vr4300, VR4300_FAULT_WAT);
+  vr4300_debug_exception(&vr4300->debug);
 }
 
diff --git a/vr4300/interface.c b/vr4300/interface.c
index 743a467..9250d2a 100644
--- a/vr4300/interface.c
+++ b/vr4300/interface.c
@@ -10,6 +10,7 @@
 
 #include "common.h"
 #include "bus/address.h"
+#include "bus/controller.h"
 #include "vr4300/cpu.h"
 #include "vr4300/interface.h"
 #ifdef _WIN32
@@ -190,3 +191,52 @@ uint64_t get_profile_sample(struct vr4300 const *vr4300, size_t i)
     return vr4300->profile_samples[i];
 }
 
+bool vr4300_read_word_vaddr(struct vr4300 *vr4300, uint64_t vaddr, uint32_t* result) {
+  if (vaddr & 0x3) {
+    // must be aligned
+    return false;
+  }
+
+  const struct segment* segment = get_segment(vaddr, vr4300->regs[VR4300_CP0_REGISTER_STATUS]);
+
+  if (!segment) {
+    return false;
+  }
+
+  uint32_t paddr;
+  bool cached;
+
+  if (segment->mapped) {
+    unsigned asid = vr4300->regs[VR4300_CP0_REGISTER_ENTRYHI] & 0xFF;
+    unsigned select, tlb_miss, index;
+    uint32_t page_mask;
+
+    tlb_miss = tlb_probe(&vr4300->cp0.tlb, vaddr, asid, &index);
+    page_mask = vr4300->cp0.page_mask[index];
+    select = ((page_mask + 1) & vaddr) != 0;
+
+    if (unlikely(tlb_miss || !(vr4300->cp0.state[index][select] & 2))) {
+      return false;
+    }
+
+    cached = ((vr4300->cp0.state[index][select] & 0x38) != 0x10);
+    paddr = (vr4300->cp0.pfn[index][select]) | (vaddr & page_mask);
+  } else {
+    paddr = vaddr - segment->offset;
+    cached = segment->cached;
+  }
+
+  if (cached) {
+    struct vr4300_dcache_line* line = vr4300_dcache_probe(&vr4300->dcache, vaddr, paddr);
+
+    if (line) {
+      memcpy(result, line->data + ((paddr & 0xf) ^ WORD_ADDR_XOR), sizeof(uint32_t));
+    } else {
+      bus_read_word(vr4300->bus, paddr, result);
+    }
+  } else {
+    bus_read_word(vr4300->bus, paddr, result);
+  }
+
+  return true;
+}
\ No newline at end of file
diff --git a/vr4300/interface.h b/vr4300/interface.h
index 745c6d6..e77a4a0 100644
--- a/vr4300/interface.h
+++ b/vr4300/interface.h
@@ -24,6 +24,15 @@ enum rcp_interrupt_mask {
 struct vr4300;
 struct vr4300_stats;
 
+enum vr4300_debug_break_reason {
+  VR4300_DEBUG_BREAK_REASON_NONE,
+  VR4300_DEBUG_BREAK_REASON_BREAKPOINT,
+  VR4300_DEBUG_BREAK_REASON_EXCEPTION,
+  VR4300_DEBUG_BREAK_REASON_PAUSE,
+};
+
+typedef void (*vr4300_debug_break_handler)(void* data, enum vr4300_debug_break_reason reason);
+
 cen64_cold struct vr4300* vr4300_alloc();
 cen64_cold void vr4300_free(struct vr4300*);
 
@@ -39,6 +48,8 @@ cen64_cold void vr4300_cycle_extra(struct vr4300 *vr4300, struct vr4300_stats *s
 uint64_t vr4300_get_register(struct vr4300 *vr4300, size_t i);
 uint64_t vr4300_get_pc(struct vr4300 *vr4300);
 
+bool vr4300_read_word_vaddr(struct vr4300 *vr4300, uint64_t vaddr, uint32_t* result);
+
 int read_mi_regs(struct vr4300 *vr4300, uint32_t address, uint32_t *word);
 int write_mi_regs(struct vr4300 *vr4300, uint32_t address, uint32_t word, uint32_t dqm);
 
@@ -51,5 +62,10 @@ void signal_dd_interrupt(struct vr4300 *vr4300);
 uint64_t get_profile_sample(struct vr4300 const *vr4300, size_t i);
 int has_profile_samples(struct vr4300 const *vr4300);
 
+cen64_cold void vr4300_signal_break(struct vr4300 *vr4300);
+cen64_cold void vr4300_set_breakpoint(struct vr4300 *vr4300, uint64_t at);
+cen64_cold void vr4300_remove_breakpoint(struct vr4300 *vr4300, uint64_t at);
+cen64_cold void vr4300_connect_debugger(struct vr4300 *vr4300, void* break_handler_data, vr4300_debug_break_handler break_handler);
+
 #endif
 
diff --git a/vr4300/pipeline.c b/vr4300/pipeline.c
index e085485..4620400 100644
--- a/vr4300/pipeline.c
+++ b/vr4300/pipeline.c
@@ -522,6 +522,8 @@ void vr4300_cycle_(struct vr4300 *vr4300) {
     if (vr4300_wb_stage(vr4300))
       return;
 
+    vr4300_debug_check_breakpoints(&vr4300->debug, vr4300_get_pc(vr4300));
+
     if (vr4300_dc_stage(vr4300))
       return;