diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c
index 702dbef49..4a4ea53dc 100644
--- a/src/server/gdb_server.c
+++ b/src/server/gdb_server.c
@@ -1779,7 +1779,7 @@ static int gdb_breakpoint_watchpoint_packet(struct connection *connection,
 		case 4:
 		{
 			if (packet[0] == 'Z') {
-				retval = watchpoint_add(target, address, size, wp_type, 0, 0xffffffffu);
+				retval = watchpoint_add(target, address, size, wp_type, 0, WATCHPOINT_IGNORE_DATA_VALUE_MASK);
 				if (retval == ERROR_NOT_IMPLEMENTED) {
 					/* Send empty reply to report that watchpoints of this type are not supported */
 					gdb_put_packet(connection, "", 0);
diff --git a/src/target/arm7_9_common.c b/src/target/arm7_9_common.c
index bbdbc4981..ad814e054 100644
--- a/src/target/arm7_9_common.c
+++ b/src/target/arm7_9_common.c
@@ -451,6 +451,7 @@ static int arm7_9_set_watchpoint(struct target *target, struct watchpoint *watch
 	struct arm7_9_common *arm7_9 = target_to_arm7_9(target);
 	int rw_mask = 1;
 	uint32_t mask;
+	const uint32_t wp_data_mask = watchpoint->mask;
 
 	mask = watchpoint->length - 1;
 
@@ -469,8 +470,8 @@ static int arm7_9_set_watchpoint(struct target *target, struct watchpoint *watch
 			watchpoint->address);
 		embeddedice_set_reg(&arm7_9->eice_cache->reg_list[EICE_W0_ADDR_MASK], mask);
 		embeddedice_set_reg(&arm7_9->eice_cache->reg_list[EICE_W0_DATA_MASK],
-			watchpoint->mask);
-		if (watchpoint->mask != 0xffffffffu)
+			wp_data_mask);
+		if (wp_data_mask != (uint32_t)WATCHPOINT_IGNORE_DATA_VALUE_MASK)
 			embeddedice_set_reg(&arm7_9->eice_cache->reg_list[EICE_W0_DATA_VALUE],
 				watchpoint->value);
 		embeddedice_set_reg(&arm7_9->eice_cache->reg_list[EICE_W0_CONTROL_MASK],
@@ -488,8 +489,8 @@ static int arm7_9_set_watchpoint(struct target *target, struct watchpoint *watch
 			watchpoint->address);
 		embeddedice_set_reg(&arm7_9->eice_cache->reg_list[EICE_W1_ADDR_MASK], mask);
 		embeddedice_set_reg(&arm7_9->eice_cache->reg_list[EICE_W1_DATA_MASK],
-			watchpoint->mask);
-		if (watchpoint->mask != 0xffffffffu)
+			wp_data_mask);
+		if (wp_data_mask != (uint32_t)WATCHPOINT_IGNORE_DATA_VALUE_MASK)
 			embeddedice_set_reg(&arm7_9->eice_cache->reg_list[EICE_W1_DATA_VALUE],
 				watchpoint->value);
 		embeddedice_set_reg(&arm7_9->eice_cache->reg_list[EICE_W1_CONTROL_MASK],
diff --git a/src/target/arm_dpm.c b/src/target/arm_dpm.c
index fd6fb263f..ab9b50e23 100644
--- a/src/target/arm_dpm.c
+++ b/src/target/arm_dpm.c
@@ -918,7 +918,7 @@ static int dpm_watchpoint_setup(struct arm_dpm *dpm, unsigned index_t,
 	uint32_t control;
 
 	/* this hardware doesn't support data value matching or masking */
-	if (wp->value || wp->mask != ~(uint32_t)0) {
+	if (wp->mask != WATCHPOINT_IGNORE_DATA_VALUE_MASK) {
 		LOG_DEBUG("watchpoint values and masking not supported");
 		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 	}
diff --git a/src/target/armv8_dpm.c b/src/target/armv8_dpm.c
index d1eefe5b3..9ba6b5453 100644
--- a/src/target/armv8_dpm.c
+++ b/src/target/armv8_dpm.c
@@ -1210,7 +1210,7 @@ static int dpmv8_watchpoint_setup(struct arm_dpm *dpm, unsigned index_t,
 	uint32_t control;
 
 	/* this hardware doesn't support data value matching or masking */
-	if (wp->value || wp->mask != ~(uint32_t)0) {
+	if (wp->mask != WATCHPOINT_IGNORE_DATA_VALUE_MASK) {
 		LOG_DEBUG("watchpoint values and masking not supported");
 		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 	}
diff --git a/src/target/breakpoints.c b/src/target/breakpoints.c
index bbaff4e75..4d268cebb 100644
--- a/src/target/breakpoints.c
+++ b/src/target/breakpoints.c
@@ -393,7 +393,7 @@ struct breakpoint *breakpoint_find(struct target *target, target_addr_t address)
 }
 
 static int watchpoint_add_internal(struct target *target, target_addr_t address,
-		uint32_t length, enum watchpoint_rw rw, uint32_t value, uint32_t mask)
+		uint32_t length, enum watchpoint_rw rw, uint64_t value, uint64_t mask)
 {
 	struct watchpoint *watchpoint = target->watchpoints;
 	struct watchpoint **watchpoint_p = &target->watchpoints;
@@ -460,7 +460,7 @@ bye:
 }
 
 int watchpoint_add(struct target *target, target_addr_t address,
-		uint32_t length, enum watchpoint_rw rw, uint32_t value, uint32_t mask)
+		uint32_t length, enum watchpoint_rw rw, uint64_t value, uint64_t mask)
 {
 	if (target->smp) {
 		struct target_list *head;
diff --git a/src/target/breakpoints.h b/src/target/breakpoints.h
index a9ae48435..d447515bf 100644
--- a/src/target/breakpoints.h
+++ b/src/target/breakpoints.h
@@ -36,11 +36,13 @@ struct breakpoint {
 	int linked_brp;
 };
 
+#define WATCHPOINT_IGNORE_DATA_VALUE_MASK (~(uint64_t)0)
+
 struct watchpoint {
 	target_addr_t address;
 	uint32_t length;
-	uint32_t mask;
-	uint32_t value;
+	uint64_t mask;
+	uint64_t value;
 	enum watchpoint_rw rw;
 	bool is_set;
 	unsigned int number;
@@ -69,7 +71,7 @@ static inline void breakpoint_hw_set(struct breakpoint *breakpoint, unsigned int
 void watchpoint_clear_target(struct target *target);
 int watchpoint_add(struct target *target,
 		target_addr_t address, uint32_t length,
-		enum watchpoint_rw rw, uint32_t value, uint32_t mask);
+		enum watchpoint_rw rw, uint64_t value, uint64_t mask);
 void watchpoint_remove(struct target *target, target_addr_t address);
 
 /* report type and address of just hit watchpoint */
diff --git a/src/target/cortex_m.c b/src/target/cortex_m.c
index 9541caa79..987dc9b24 100644
--- a/src/target/cortex_m.c
+++ b/src/target/cortex_m.c
@@ -2046,8 +2046,14 @@ int cortex_m_add_watchpoint(struct target *target, struct watchpoint *watchpoint
 		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 	}
 
-	/* hardware doesn't support data value masking */
-	if (watchpoint->mask != ~(uint32_t)0) {
+	/* REVISIT This DWT may well be able to watch for specific data
+	 * values.  Requires comparator #1 to set DATAVMATCH and match
+	 * the data, and another comparator (DATAVADDR0) matching addr.
+	 *
+	 * NOTE: hardware doesn't support data value masking, so we'll need
+	 * to check that mask is zero
+	 */
+	if (watchpoint->mask != WATCHPOINT_IGNORE_DATA_VALUE_MASK) {
 		LOG_TARGET_DEBUG(target, "watchpoint value masks not supported");
 		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 	}
@@ -2068,18 +2074,6 @@ int cortex_m_add_watchpoint(struct target *target, struct watchpoint *watchpoint
 		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 	}
 
-	/* Caller doesn't seem to be able to describe watching for data
-	 * values of zero; that flags "no value".
-	 *
-	 * REVISIT This DWT may well be able to watch for specific data
-	 * values.  Requires comparator #1 to set DATAVMATCH and match
-	 * the data, and another comparator (DATAVADDR0) matching addr.
-	 */
-	if (watchpoint->value) {
-		LOG_TARGET_DEBUG(target, "data value watchpoint not YET supported");
-		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
-	}
-
 	cortex_m->dwt_comp_available--;
 	LOG_TARGET_DEBUG(target, "dwt_comp_available: %d", cortex_m->dwt_comp_available);
 
diff --git a/src/target/target.c b/src/target/target.c
index 89eaa23d8..96f4ae7d3 100644
--- a/src/target/target.c
+++ b/src/target/target.c
@@ -4061,8 +4061,8 @@ COMMAND_HANDLER(handle_wp_command)
 		while (watchpoint) {
 			command_print(CMD, "address: " TARGET_ADDR_FMT
 					", len: 0x%8.8" PRIx32
-					", r/w/a: %i, value: 0x%8.8" PRIx32
-					", mask: 0x%8.8" PRIx32,
+					", r/w/a: %i, value: 0x%8.8" PRIx64
+					", mask: 0x%8.8" PRIx64,
 					watchpoint->address,
 					watchpoint->length,
 					(int)watchpoint->rw,
@@ -4076,15 +4076,20 @@ COMMAND_HANDLER(handle_wp_command)
 	enum watchpoint_rw type = WPT_ACCESS;
 	target_addr_t addr = 0;
 	uint32_t length = 0;
-	uint32_t data_value = 0x0;
-	uint32_t data_mask = 0xffffffff;
+	uint64_t data_value = 0x0;
+	uint64_t data_mask = WATCHPOINT_IGNORE_DATA_VALUE_MASK;
+	bool mask_specified = false;
 
 	switch (CMD_ARGC) {
 	case 5:
-		COMMAND_PARSE_NUMBER(u32, CMD_ARGV[4], data_mask);
+		COMMAND_PARSE_NUMBER(u64, CMD_ARGV[4], data_mask);
+		mask_specified = true;
 		/* fall through */
 	case 4:
-		COMMAND_PARSE_NUMBER(u32, CMD_ARGV[3], data_value);
+		COMMAND_PARSE_NUMBER(u64, CMD_ARGV[3], data_value);
+		// if user specified only data value without mask - the mask should be 0
+		if (!mask_specified)
+			data_mask = 0;
 		/* fall through */
 	case 3:
 		switch (CMD_ARGV[2][0]) {
diff --git a/src/target/xscale.c b/src/target/xscale.c
index 03aa5166b..fbf43516d 100644
--- a/src/target/xscale.c
+++ b/src/target/xscale.c
@@ -2296,7 +2296,7 @@ static int xscale_add_watchpoint(struct target *target,
 		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 	}
 
-	if (watchpoint->value)
+	if (watchpoint->mask != WATCHPOINT_IGNORE_DATA_VALUE_MASK)
 		LOG_WARNING("xscale does not support value, mask arguments; ignoring");
 
 	/* check that length is a power of two */
diff --git a/src/target/xtensa/xtensa.c b/src/target/xtensa/xtensa.c
index 431be894b..c575b534e 100644
--- a/src/target/xtensa/xtensa.c
+++ b/src/target/xtensa/xtensa.c
@@ -2570,7 +2570,7 @@ int xtensa_watchpoint_add(struct target *target, struct watchpoint *watchpoint)
 		return ERROR_TARGET_NOT_HALTED;
 	}
 
-	if (watchpoint->mask != ~(uint32_t)0) {
+	if (watchpoint->mask != WATCHPOINT_IGNORE_DATA_VALUE_MASK) {
 		LOG_TARGET_ERROR(target, "watchpoint value masks not supported");
 		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 	}