diff --git a/drivers/device.h b/drivers/device.h
index 416ef13..4c170ba 100644
--- a/drivers/device.h
+++ b/drivers/device.h
@@ -53,7 +53,9 @@ typedef enum {
 
 typedef enum {
 	DEVICE_BPTYPE_BREAK,
-	DEVICE_BPTYPE_WATCH
+	DEVICE_BPTYPE_WATCH,
+	DEVICE_BPTYPE_READ,
+	DEVICE_BPTYPE_WRITE
 } device_bptype_t;
 
 struct device_breakpoint {
diff --git a/drivers/gdbc.c b/drivers/gdbc.c
index 05af2e2..63cc04f 100644
--- a/drivers/gdbc.c
+++ b/drivers/gdbc.c
@@ -226,6 +226,14 @@ static int bp_send(struct gdb_data *gdb, int c, address_t addr,
 		type_code = 1;
 		break;
 
+	case DEVICE_BPTYPE_WRITE:
+		type_code = 2;
+		break;
+
+	case DEVICE_BPTYPE_READ:
+		type_code = 3;
+		break;
+
 	case DEVICE_BPTYPE_WATCH:
 		type_code = 4;
 		break;
diff --git a/drivers/sim.c b/drivers/sim.c
index 0d5d5e4..a415d2d 100644
--- a/drivers/sim.c
+++ b/drivers/sim.c
@@ -53,7 +53,8 @@ struct sim_device {
 		(dev)->memory[offset | 1] = (value) >> 8;	\
 	} while (0);
 
-static void watchpoint_check(struct sim_device *dev, uint16_t addr)
+static void watchpoint_check(struct sim_device *dev, uint16_t addr,
+			     int is_write)
 {
 	int i;
 
@@ -62,8 +63,10 @@ static void watchpoint_check(struct sim_device *dev, uint16_t addr)
 			&dev->base.breakpoints[i];
 
 		if ((bp->flags & DEVICE_BP_ENABLED) &&
-		    bp->type == DEVICE_BPTYPE_WATCH &&
-		    bp->addr == addr) {
+		    (bp->addr == addr) &&
+		    ((bp->type == DEVICE_BPTYPE_WATCH ||
+		      (bp->type == DEVICE_BPTYPE_READ && !is_write) ||
+		      (bp->type == DEVICE_BPTYPE_WRITE && is_write)))) {
 			dev->watchpoint_hit = 1;
 			return;
 		}
@@ -133,12 +136,12 @@ static int fetch_operand(struct sim_device *dev,
 		break;
 	}
 
-	watchpoint_check(dev, addr);
-
 	if (addr_ret)
 		*addr_ret = addr;
 
 	if (data_ret) {
+		watchpoint_check(dev, addr, 0);
+
 		*data_ret = MEM_GETW(dev, addr) & mask;
 
 		if (addr < MEM_IO_END) {
@@ -172,7 +175,7 @@ static int store_operand(struct sim_device *dev,
 		return 0;
 	}
 
-	watchpoint_check(dev, addr);
+	watchpoint_check(dev, addr, 1);
 
 	if (is_byte)
 		MEM_SETB(dev, addr, data);
diff --git a/drivers/tilib.c b/drivers/tilib.c
index c5220ef..59affbe 100644
--- a/drivers/tilib.c
+++ b/drivers/tilib.c
@@ -324,13 +324,14 @@ static void load_break(BpParameter_t *param, address_t addr)
 	param->wExtCombine = 0; /* not used? */
 }
 
-static void load_watch(BpParameter_t *param, address_t addr)
+static void load_complex(BpParameter_t *param, address_t addr,
+			 BpAccess_t acc)
 {
 	param->bpMode = BP_COMPLEX;
 	param->lAddrVal = addr;
 	param->bpType = BP_MAB;
 	param->lReg = 0; /* not used (only for register-write) */
-	param->bpAccess = BP_NO_FETCH;
+	param->bpAccess = acc;
 	param->bpAction = BP_BRK;
 	param->bpOperat = BP_EQUAL;
 	param->lMask = 0xffffff;
@@ -338,7 +339,7 @@ static void load_watch(BpParameter_t *param, address_t addr)
 	param->bpRangeAction = 0; /* not used */
 	param->bpCondition = BP_NO_COND;
 	param->lCondMdbVal = 0;
-	param->bpCondAccess = BP_NO_FETCH;
+	param->bpCondAccess = acc;
 	param->lCondMask = 0; /* what's this? */
 	param->bpCondOperat = BP_EQUAL;
 	param->wExtCombine = 0; /* not used? */
@@ -362,7 +363,17 @@ static int refresh_bps(struct tilib_device *dev)
 				break;
 
 			case DEVICE_BPTYPE_WATCH:
-				load_watch(&param, bp->addr);
+				load_complex(&param, bp->addr, BP_NO_FETCH);
+				break;
+
+			case DEVICE_BPTYPE_READ:
+				load_complex(&param, bp->addr,
+					     BP_READ_DMA);
+				break;
+
+			case DEVICE_BPTYPE_WRITE:
+				load_complex(&param, bp->addr,
+					     BP_WRITE_DMA);
 				break;
 			}
 		} else {
diff --git a/mspdebug.man b/mspdebug.man
index 53863b2..b349082 100644
--- a/mspdebug.man
+++ b/mspdebug.man
@@ -408,6 +408,10 @@ Add a new watchpoint. The watchpoint location is an address expression, and
 an optional index may be specified. Watchpoints are considered to be a type
 of breakpoint and can be inspected or removed using the \fBbreak\fR and
 \fBdelbreak\fR commands. Note that not all drivers support watchpoints.
+.IP "\fBsetwatch_r\fR \fIaddress\fR [\fIindex\fR]"
+Add a watchpoint which is triggered only on read access.
+.IP "\fBsetwatch_w\fR \fIaddress\fR [\fIindex\fR]"
+Add a watchpoint which is triggered only on write access.
 .IP "\fBsimio add\fR \fIclass\fR \fIname\fR [\fIargs ...\fR]"
 Add a new peripheral to the IO simulator. The \fIclass\fR parameter may be
 any of the peripheral types named in the output of the \fBsimio classes\fR
diff --git a/ui/cmddb.c b/ui/cmddb.c
index c804ca5..512b080 100644
--- a/ui/cmddb.c
+++ b/ui/cmddb.c
@@ -68,6 +68,20 @@ const struct cmddb_record commands[] = {
 "setwatch <addr> [index]\n"
 "    Set a watchpoint. If no index is specified. the first available\n"
 "    slot will be used.\n"
+	},
+	{
+		.name = "setwatch_r",
+		.func = cmd_setwatch_r,
+		.help =
+"setwatch_r <addr> [index]\n"
+"    Set a read-only watchpoint.\n"
+	},
+	{
+		.name = "setwatch_w",
+		.func = cmd_setwatch_w,
+		.help =
+"setwatch_w <addr> [index]\n"
+"    Set a write-only watchpoint.\n"
 	},
 	{
 		.name = "delbreak",
diff --git a/ui/devcmd.c b/ui/devcmd.c
index c776e93..b96afd2 100644
--- a/ui/devcmd.c
+++ b/ui/devcmd.c
@@ -615,6 +615,16 @@ int cmd_setwatch(char **arg)
 	return do_setbreak(DEVICE_BPTYPE_WATCH, arg);
 }
 
+int cmd_setwatch_w(char **arg)
+{
+	return do_setbreak(DEVICE_BPTYPE_WRITE, arg);
+}
+
+int cmd_setwatch_r(char **arg)
+{
+	return do_setbreak(DEVICE_BPTYPE_READ, arg);
+}
+
 int cmd_delbreak(char **arg)
 {
 	char *index_text = get_arg(arg);
@@ -661,10 +671,22 @@ int cmd_break(char **arg)
 			print_address(bp->addr, name, sizeof(name));
 			printc("    %d. %s", i, name);
 
-			if (bp->type == DEVICE_BPTYPE_WATCH) {
+			switch (bp->type) {
+			case DEVICE_BPTYPE_WATCH:
 				printc(" [watchpoint]\n");
-			} else {
+				break;
+
+			case DEVICE_BPTYPE_READ:
+				printc(" [read watchpoint]\n");
+				break;
+
+			case DEVICE_BPTYPE_WRITE:
+				printc(" [write watchpoint]\n");
+				break;
+
+			case DEVICE_BPTYPE_BREAK:
 				printc("\n");
+				break;
 			}
 		}
 	}
diff --git a/ui/devcmd.h b/ui/devcmd.h
index f223eaa..35b28b9 100644
--- a/ui/devcmd.h
+++ b/ui/devcmd.h
@@ -33,6 +33,8 @@ int cmd_prog(char **arg);
 int cmd_load(char **arg);
 int cmd_setbreak(char **arg);
 int cmd_setwatch(char **arg);
+int cmd_setwatch_r(char **arg);
+int cmd_setwatch_w(char **arg);
 int cmd_delbreak(char **arg);
 int cmd_break(char **arg);
 int cmd_locka(char **arg);
diff --git a/ui/gdb.c b/ui/gdb.c
index 262fb26..1e9520b 100644
--- a/ui/gdb.c
+++ b/ui/gdb.c
@@ -329,6 +329,14 @@ static int set_breakpoint(struct gdb_data *data, int enable, char *buf)
 		type = DEVICE_BPTYPE_BREAK;
 		break;
 
+	case 2:
+		type = DEVICE_BPTYPE_WRITE;
+		break;
+
+	case 3:
+		type = DEVICE_BPTYPE_READ;
+		break;
+
 	case 4:
 		type = DEVICE_BPTYPE_WATCH;
 		break;