diff --git a/src/jtag/commands.c b/src/jtag/commands.c
index c679c56c5..a15af68db 100644
--- a/src/jtag/commands.c
+++ b/src/jtag/commands.c
@@ -210,14 +210,14 @@ int jtag_build_buffer(const struct scan_command *cmd, uint8_t **buffer)
 						? DEBUG_JTAG_IOZ
 								: cmd->fields[i].num_bits);
 
-				LOG_DEBUG("fields[%u].out_value[%i]: 0x%s", i,
+				LOG_DEBUG("fields[%u].out_value[%u]: 0x%s", i,
 						cmd->fields[i].num_bits, char_buf);
 				free(char_buf);
 			}
 			buf_set_buf(cmd->fields[i].out_value, 0, *buffer,
 					bit_count, cmd->fields[i].num_bits);
 		} else {
-			LOG_DEBUG_IO("fields[%u].out_value[%i]: NULL",
+			LOG_DEBUG_IO("fields[%u].out_value[%u]: NULL",
 					i, cmd->fields[i].num_bits);
 		}
 
@@ -242,7 +242,7 @@ int jtag_read_buffer(uint8_t *buffer, const struct scan_command *cmd)
 		 * are specified we don't have to examine this field
 		 */
 		if (cmd->fields[i].in_value) {
-			int num_bits = cmd->fields[i].num_bits;
+			const unsigned int num_bits = cmd->fields[i].num_bits;
 			uint8_t *captured = buf_set_buf(buffer, bit_count,
 					malloc(DIV_ROUND_UP(num_bits, 8)), 0, num_bits);
 
@@ -252,7 +252,7 @@ int jtag_read_buffer(uint8_t *buffer, const struct scan_command *cmd)
 						? DEBUG_JTAG_IOZ
 								: num_bits);
 
-				LOG_DEBUG("fields[%u].in_value[%i]: 0x%s",
+				LOG_DEBUG("fields[%u].in_value[%u]: 0x%s",
 						i, num_bits, char_buf);
 				free(char_buf);
 			}
diff --git a/src/jtag/core.c b/src/jtag/core.c
index a8190dd23..261de9861 100644
--- a/src/jtag/core.c
+++ b/src/jtag/core.c
@@ -964,12 +964,12 @@ int default_interface_jtag_execute_queue(void)
 					struct scan_field *field = cmd->cmd.scan->fields + i;
 					if (field->out_value) {
 						char *str = buf_to_hex_str(field->out_value, field->num_bits);
-						LOG_DEBUG_IO("  %db out: %s", field->num_bits, str);
+						LOG_DEBUG_IO("  %ub out: %s", field->num_bits, str);
 						free(str);
 					}
 					if (field->in_value) {
 						char *str = buf_to_hex_str(field->in_value, field->num_bits);
-						LOG_DEBUG_IO("  %db  in: %s", field->num_bits, str);
+						LOG_DEBUG_IO("  %ub  in: %s", field->num_bits, str);
 						free(str);
 					}
 				}
@@ -1337,7 +1337,7 @@ static int jtag_validate_ircapture(void)
 	int retval;
 
 	/* when autoprobing, accommodate huge IR lengths */
-	int total_ir_length = 0;
+	unsigned int total_ir_length = 0;
 	for (tap = jtag_tap_next_enabled(NULL); tap; tap = jtag_tap_next_enabled(tap)) {
 		if (tap->ir_length == 0)
 			total_ir_length += JTAG_IRLEN_MAX;
diff --git a/src/jtag/drivers/bitq.c b/src/jtag/drivers/bitq.c
index 6816b9b86..ef870e648 100644
--- a/src/jtag/drivers/bitq.c
+++ b/src/jtag/drivers/bitq.c
@@ -19,7 +19,7 @@ struct bitq_interface *bitq_interface; /* low level bit queue interface */
 struct bitq_state {
 	struct jtag_command *cmd; /* command currently processed */
 	unsigned int field_idx; /* index of field currently being processed */
-	int bit_pos; /* position of bit currently being processed */
+	unsigned int bit_pos; /* position of bit currently being processed */
 	int status; /* processing status */
 };
 static struct bitq_state bitq_in_state;
@@ -142,11 +142,10 @@ static void bitq_runtest(unsigned int num_cycles)
 
 static void bitq_scan_field(struct scan_field *field, int do_pause)
 {
-	int bit_cnt;
 	int tdo_req;
 
 	const uint8_t *out_ptr;
-	uint8_t  out_mask;
+	uint8_t out_mask;
 
 	if (field->in_value)
 		tdo_req = 1;
@@ -155,7 +154,7 @@ static void bitq_scan_field(struct scan_field *field, int do_pause)
 
 	if (!field->out_value) {
 		/* just send zeros and request data from TDO */
-		for (bit_cnt = field->num_bits; bit_cnt > 1; bit_cnt--)
+		for (unsigned int i = 0; i < (field->num_bits - 1); i++)
 			bitq_io(0, 0, tdo_req);
 
 		bitq_io(do_pause, 0, tdo_req);
@@ -163,7 +162,7 @@ static void bitq_scan_field(struct scan_field *field, int do_pause)
 		/* send data, and optionally request TDO */
 		out_mask = 0x01;
 		out_ptr  = field->out_value;
-		for (bit_cnt = field->num_bits; bit_cnt > 1; bit_cnt--) {
+		for (unsigned int i = 0; i < (field->num_bits - 1); i++) {
 			bitq_io(0, ((*out_ptr) & out_mask) != 0, tdo_req);
 			if (out_mask == 0x80) {
 				out_mask = 0x01;
diff --git a/src/jtag/drivers/cmsis_dap.c b/src/jtag/drivers/cmsis_dap.c
index 243b01c63..a6dcfcd3d 100644
--- a/src/jtag/drivers/cmsis_dap.c
+++ b/src/jtag/drivers/cmsis_dap.c
@@ -1772,11 +1772,11 @@ static void cmsis_dap_execute_scan(struct jtag_command *cmd)
 	cmsis_dap_end_state(cmd->cmd.scan->end_state);
 
 	struct scan_field *field = cmd->cmd.scan->fields;
-	unsigned scan_size = 0;
+	unsigned int scan_size = 0;
 
 	for (unsigned int i = 0; i < cmd->cmd.scan->num_fields; i++, field++) {
 		scan_size += field->num_bits;
-		LOG_DEBUG_IO("%s%s field %u/%u %d bits",
+		LOG_DEBUG_IO("%s%s field %u/%u %u bits",
 			field->in_value ? "in" : "",
 			field->out_value ? "out" : "",
 			i,
diff --git a/src/jtag/drivers/ftdi.c b/src/jtag/drivers/ftdi.c
index 4f253fa6d..82117f12c 100644
--- a/src/jtag/drivers/ftdi.c
+++ b/src/jtag/drivers/ftdi.c
@@ -451,7 +451,7 @@ static void ftdi_execute_scan(struct jtag_command *cmd)
 
 	for (unsigned int i = 0; i < cmd->cmd.scan->num_fields; i++, field++) {
 		scan_size += field->num_bits;
-		LOG_DEBUG_IO("%s%s field %u/%u %d bits",
+		LOG_DEBUG_IO("%s%s field %u/%u %u bits",
 			field->in_value ? "in" : "",
 			field->out_value ? "out" : "",
 			i,
diff --git a/src/jtag/drivers/jlink.c b/src/jtag/drivers/jlink.c
index ff3916735..21a5da887 100644
--- a/src/jtag/drivers/jlink.c
+++ b/src/jtag/drivers/jlink.c
@@ -183,7 +183,7 @@ static void jlink_execute_scan(struct jtag_command *cmd)
 
 	for (unsigned int i = 0; i < cmd->cmd.scan->num_fields; i++, field++) {
 		scan_size += field->num_bits;
-		LOG_DEBUG_IO("%s%s field %u/%u %d bits",
+		LOG_DEBUG_IO("%s%s field %u/%u %u bits",
 			field->in_value ? "in" : "",
 			field->out_value ? "out" : "",
 			i,
diff --git a/src/jtag/jtag.h b/src/jtag/jtag.h
index 520b5b8c0..f0a0fe5e1 100644
--- a/src/jtag/jtag.h
+++ b/src/jtag/jtag.h
@@ -86,7 +86,7 @@ extern tap_state_t cmd_queue_cur_state;
  */
 struct scan_field {
 	/** The number of bits this field specifies */
-	int num_bits;
+	unsigned int num_bits;
 	/** A pointer to value to be scanned into the device */
 	const uint8_t *out_value;
 	/** A pointer to a 32-bit memory location for data scanned out */
diff --git a/src/target/riscv/batch.c b/src/target/riscv/batch.c
index d39967e4d..d4bdadf17 100644
--- a/src/target/riscv/batch.c
+++ b/src/target/riscv/batch.c
@@ -211,12 +211,12 @@ void dump_field(int idle, const struct scan_field *field)
 
 		log_printf_lf(LOG_LVL_DEBUG,
 				__FILE__, __LINE__, __PRETTY_FUNCTION__,
-				"%db %s %08x @%02x -> %s %08x @%02x; %di",
+				"%ub %s %08x @%02x -> %s %08x @%02x; %di",
 				field->num_bits, op_string[out_op], out_data, out_address,
 				status_string[in_op], in_data, in_address, idle);
 	} else {
 		log_printf_lf(LOG_LVL_DEBUG,
-				__FILE__, __LINE__, __PRETTY_FUNCTION__, "%db %s %08x @%02x -> ?; %di",
+				__FILE__, __LINE__, __PRETTY_FUNCTION__, "%ub %s %08x @%02x -> ?; %di",
 				field->num_bits, op_string[out_op], out_data, out_address, idle);
 	}
 }
diff --git a/src/target/riscv/riscv-011.c b/src/target/riscv/riscv-011.c
index be296cdd8..565721c28 100644
--- a/src/target/riscv/riscv-011.c
+++ b/src/target/riscv/riscv-011.c
@@ -412,7 +412,7 @@ static void dump_field(const struct scan_field *field)
 
 	log_printf_lf(LOG_LVL_DEBUG,
 			__FILE__, __LINE__, "scan",
-			"%db %s %c%c:%08x @%02x -> %s %c%c:%08x @%02x",
+			"%ub %s %c%c:%08x @%02x -> %s %c%c:%08x @%02x",
 			field->num_bits,
 			op_string[out_op], out_interrupt, out_haltnot, out_data,
 			out_address,
diff --git a/src/target/riscv/riscv-013.c b/src/target/riscv/riscv-013.c
index 0aa82031c..dbf9aad1d 100644
--- a/src/target/riscv/riscv-013.c
+++ b/src/target/riscv/riscv-013.c
@@ -389,7 +389,7 @@ static void dump_field(int idle, const struct scan_field *field)
 
 	log_printf_lf(LOG_LVL_DEBUG,
 			__FILE__, __LINE__, "scan",
-			"%db %s %08x @%02x -> %s %08x @%02x; %di",
+			"%ub %s %08x @%02x -> %s %08x @%02x; %di",
 			field->num_bits, op_string[out_op], out_data, out_address,
 			status_string[in_op], in_data, in_address, idle);