diff --git a/src/platforms/hosted/dap.c b/src/platforms/hosted/dap.c
index e3d53e0c..196ed7c6 100644
--- a/src/platforms/hosted/dap.c
+++ b/src/platforms/hosted/dap.c
@@ -32,6 +32,7 @@
 
 /*- Includes ----------------------------------------------------------------*/
 #include <general.h>
+#include "exception.h"
 #include "dap.h"
 #include "jtag_scan.h"
 
@@ -329,12 +330,13 @@ static uint32_t wait_word(uint8_t *buf, int size, int len, uint8_t *dp_fault)
 			break;
 	} while (buf[1] == DAP_TRANSFER_WAIT);
 
-	if (buf[1] > DAP_TRANSFER_WAIT) {
-		DEBUG_WARN("dap wait_word reg %x fault %x\n",
-				   cmd_copy[3], buf[1]);
+	if(buf[1] == SWDP_ACK_FAULT) {
 		*dp_fault = 1;
 		return 0;
 	}
+
+	if(buf[1] != SWDP_ACK_OK)
+		raise_exception(EXCEPTION_ERROR, "SWDP invalid ACK");
 	uint32_t res =
 		((uint32_t)buf[5] << 24) | ((uint32_t)buf[4] << 16) |
 		((uint32_t)buf[3] << 8) | (uint32_t)buf[2];
diff --git a/src/target/adiv5.h b/src/target/adiv5.h
index 63abecf4..95c62f62 100644
--- a/src/target/adiv5.h
+++ b/src/target/adiv5.h
@@ -170,7 +170,7 @@ typedef struct ADIv5_DP_s {
 	void (*seq_out_parity)(uint32_t MS, int ticks);
 	uint32_t (*seq_in)(int ticks);
 	bool (*seq_in_parity)(uint32_t *ret, int ticks);
-	/* dp_low_write returns true if no OK resonse. */
+	/* dp_low_write returns true if no OK resonse, but ignores errors */
 	bool (*dp_low_write)(struct ADIv5_DP_s *dp, uint16_t addr,
 						 const uint32_t data);
 	uint32_t (*dp_read)(struct ADIv5_DP_s *dp, uint16_t addr);