diff --git a/src/platforms/libftdi/jtagtap.c b/src/platforms/libftdi/jtagtap.c
index 0ac8b6c..11256d0 100644
--- a/src/platforms/libftdi/jtagtap.c
+++ b/src/platforms/libftdi/jtagtap.c
@@ -185,11 +185,11 @@ jtagtap_tdi_tdo_seq(uint8_t *DO, const uint8_t final_tms, const uint8_t *DI, int
 }
 #endif
 
-uint8_t jtagtap_next(uint8_t dTMS, uint8_t dTDO)
+uint8_t jtagtap_next(uint8_t dTMS, uint8_t dTDI)
 {
 	uint8_t ret;
 	uint8_t tmp[3] = "\x6B\x00\x00";
-	tmp[2] = (dTDO?0x80:0) | (dTMS?0x01:0);
+	tmp[2] = (dTDI?0x80:0) | (dTMS?0x01:0);
 //	assert(ftdi_write_data(ftdic, tmp, 3) == 3);
 //	while(ftdi_read_data(ftdic, &ret, 1) != 1);
 	platform_buffer_write(tmp, 3);
@@ -197,7 +197,7 @@ uint8_t jtagtap_next(uint8_t dTMS, uint8_t dTDO)
 
 	ret &= 0x80;
 
-//	DEBUG("jtagtap_next(TMS = %d, TDO = %d) = %02X\n", dTMS, dTDO, ret);
+//	DEBUG("jtagtap_next(TMS = %d, TDI = %d) = %02X\n", dTMS, dTDI, ret);
 
 	return ret;
 }
diff --git a/src/platforms/stm32/jtagtap.c b/src/platforms/stm32/jtagtap.c
index ecd0698..1ee8cfe 100644
--- a/src/platforms/stm32/jtagtap.c
+++ b/src/platforms/stm32/jtagtap.c
@@ -51,17 +51,17 @@ void jtagtap_reset(void)
 	jtagtap_soft_reset();
 }
 
-inline uint8_t jtagtap_next(uint8_t dTMS, uint8_t dTDO)
+inline uint8_t jtagtap_next(uint8_t dTMS, uint8_t dTDI)
 {
 	uint16_t ret;
 
 	gpio_set_val(TMS_PORT, TMS_PIN, dTMS);
-	gpio_set_val(TDI_PORT, TDI_PIN, dTDO);
+	gpio_set_val(TDI_PORT, TDI_PIN, dTDI);
 	gpio_set(TCK_PORT, TCK_PIN);
 	ret = gpio_get(TDO_PORT, TDO_PIN);
 	gpio_clear(TCK_PORT, TCK_PIN);
 
-	//DEBUG("jtagtap_next(TMS = %d, TDO = %d) = %d\n", dTMS, dTDO, ret);
+	//DEBUG("jtagtap_next(TMS = %d, TDI = %d) = %d\n", dTMS, dTDI, ret);
 
 	return ret != 0;
 }
diff --git a/src/platforms/tm4c/jtagtap.c b/src/platforms/tm4c/jtagtap.c
index c6b8d7e..056a4fd 100644
--- a/src/platforms/tm4c/jtagtap.c
+++ b/src/platforms/tm4c/jtagtap.c
@@ -26,17 +26,17 @@ jtagtap_reset(void)
 }
 
 uint8_t
-jtagtap_next(const uint8_t dTMS, const uint8_t dTDO)
+jtagtap_next(const uint8_t dTMS, const uint8_t dTDI)
 {
 	uint16_t ret;
 
 	gpio_set_val(TMS_PORT, TMS_PIN, dTMS);
-	gpio_set_val(TDI_PORT, TDI_PIN, dTDO);
+	gpio_set_val(TDI_PORT, TDI_PIN, dTDI);
 	gpio_set(TCK_PORT, TCK_PIN);
 	ret = gpio_get(TDO_PORT, TDO_PIN);
 	gpio_clear(TCK_PORT, TCK_PIN);
 
-	DEBUG("jtagtap_next(TMS = %d, TDO = %d) = %d\n", dTMS, dTDO, ret);
+	DEBUG("jtagtap_next(TMS = %d, TDI = %d) = %d\n", dTMS, dTDI, ret);
 
 	return ret != 0;
 }