diff --git a/firmware/common/cpld_jtag.c b/firmware/common/cpld_jtag.c
index 3e34f0b9..0948858c 100644
--- a/firmware/common/cpld_jtag.c
+++ b/firmware/common/cpld_jtag.c
@@ -29,47 +29,6 @@ static refill_buffer_cb refill_buffer;
 static uint32_t xsvf_buffer_len, xsvf_pos;
 static unsigned char* xsvf_buffer;
 
-void cpld_jtag_setup(jtag_t* const jtag) {
-	scu_pinmux(SCU_PINMUX_CPLD_TDO, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION4);
-	scu_pinmux(SCU_PINMUX_CPLD_TCK, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-	scu_pinmux(SCU_PINMUX_CPLD_TMS, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-	scu_pinmux(SCU_PINMUX_CPLD_TDI, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-#ifdef USER_INTERFACE_PORTAPACK
-	scu_pinmux(SCU_PINMUX_PP_TMS,   SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-	scu_pinmux(SCU_PINMUX_PP_TDO,   SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-#endif
-	
-	gpio_input(jtag->gpio->gpio_tdo);
-	gpio_output(jtag->gpio->gpio_tck);
-	gpio_output(jtag->gpio->gpio_tms);
-	gpio_output(jtag->gpio->gpio_tdi);
-#ifdef USER_INTERFACE_PORTAPACK
-	gpio_output(jtag->gpio->gpio_pp_tms);
-	gpio_input(jtag->gpio->gpio_pp_tdo);
-#endif
-}
-
-/* set pins as inputs so we don't interfere with an external JTAG device */
-void cpld_jtag_release(jtag_t* const jtag) {
-	scu_pinmux(SCU_PINMUX_CPLD_TDO, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION4);
-	scu_pinmux(SCU_PINMUX_CPLD_TCK, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-	scu_pinmux(SCU_PINMUX_CPLD_TMS, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-	scu_pinmux(SCU_PINMUX_CPLD_TDI, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-#ifdef USER_INTERFACE_PORTAPACK
-	scu_pinmux(SCU_PINMUX_PP_TMS,   SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-	scu_pinmux(SCU_PINMUX_PP_TDO,   SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-#endif
-	
-	gpio_input(jtag->gpio->gpio_tdo);
-	gpio_input(jtag->gpio->gpio_tck);
-	gpio_input(jtag->gpio->gpio_tms);
-	gpio_input(jtag->gpio->gpio_tdi);
-#ifdef USER_INTERFACE_PORTAPACK
-	gpio_input(jtag->gpio->gpio_pp_tms);
-	gpio_input(jtag->gpio->gpio_pp_tdo);
-#endif
-}
-
 /* return 0 if success else return error code see xsvfExecute() */
 int cpld_jtag_program(
 		jtag_t* const jtag,
@@ -78,12 +37,10 @@ int cpld_jtag_program(
         refill_buffer_cb refill
 ) {
 	int error;
-	cpld_jtag_setup(jtag);
 	xsvf_buffer = buffer;
 	xsvf_buffer_len = buffer_length;
         refill_buffer = refill;
 	error = xsvfExecute(jtag->gpio);
-	cpld_jtag_release(jtag);
 	
 	return error;
 }
diff --git a/firmware/common/cpld_jtag.h b/firmware/common/cpld_jtag.h
index f8ce0b0e..04292d22 100644
--- a/firmware/common/cpld_jtag.h
+++ b/firmware/common/cpld_jtag.h
@@ -43,8 +43,6 @@ typedef struct jtag_t {
 
 typedef void (*refill_buffer_cb)(void);
 
-void cpld_jtag_release(jtag_t* const jtag);
-
 /* Return 0 if success else return error code see xsvfExecute() see micro.h.
  *
  * We expect the buffer to be initially full of data. After the entire
diff --git a/firmware/common/hackrf_core.c b/firmware/common/hackrf_core.c
index d1842557..74becd01 100644
--- a/firmware/common/hackrf_core.c
+++ b/firmware/common/hackrf_core.c
@@ -758,21 +758,50 @@ void ssp1_set_mode_max5864(void)
 	spi_bus_start(max5864.bus, &ssp_config_max5864);
 }
 
+static void jtag_setup(void) {
+	/* TDI and TMS pull-ups are required in all JTAG-compliant devices.
+	 * Therefore, do not pull up TDI and TMS on HackRF CPLD, which is always present.
+	 * HackRF TMS and TDI are dedicated, just drive instead of pulling up/down.
+	 * TCK is recommended to be held low.
+	 * TDO is undriven except when in Shift-IR or Shift-DR phases, so pull down to keep from floating.
+	 * Nail down other signals before causing any transitions on TCK, to prevent undesired
+	 * state changes.
+	 */
+	/* LPC43xx pull-up and pull-down resistors are approximately 53K. */
+#ifdef USER_INTERFACE_PORTAPACK
+	gpio_set(jtag_gpio_cpld.gpio_pp_tms);
+#endif
+	gpio_set(jtag_gpio_cpld.gpio_tms);
+	gpio_set(jtag_gpio_cpld.gpio_tdi);
+	gpio_clear(jtag_gpio_cpld.gpio_tck);
+
+#ifdef USER_INTERFACE_PORTAPACK
+	/* Do not drive PortaPack-specific pins, initially, just to be cautious. */
+	gpio_input(jtag_gpio_cpld.gpio_pp_tms);
+	gpio_input(jtag_gpio_cpld.gpio_pp_tdo);
+#endif
+	gpio_output(jtag_gpio_cpld.gpio_tms);
+	gpio_output(jtag_gpio_cpld.gpio_tdi);
+	gpio_output(jtag_gpio_cpld.gpio_tck);
+	gpio_input(jtag_gpio_cpld.gpio_tdo);
+
+	/* Configure CPLD JTAG pins */
+#ifdef USER_INTERFACE_PORTAPACK
+	scu_pinmux(SCU_PINMUX_PP_TMS,   SCU_GPIO_PUP    | SCU_CONF_FUNCTION0);
+	scu_pinmux(SCU_PINMUX_PP_TDO,   SCU_GPIO_PDN    | SCU_CONF_FUNCTION0);
+#endif
+	scu_pinmux(SCU_PINMUX_CPLD_TMS, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
+	scu_pinmux(SCU_PINMUX_CPLD_TDI, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
+	scu_pinmux(SCU_PINMUX_CPLD_TDO, SCU_GPIO_PDN    | SCU_CONF_FUNCTION4);
+	scu_pinmux(SCU_PINMUX_CPLD_TCK, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
+}
+
 void pin_setup(void) {
 	/* Configure all GPIO as Input (safe state) */
 	gpio_init();
 
-	/* Release CPLD JTAG pins */
-	scu_pinmux(SCU_PINMUX_CPLD_TDO, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION4);
-	scu_pinmux(SCU_PINMUX_CPLD_TCK, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-	scu_pinmux(SCU_PINMUX_CPLD_TMS, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-	scu_pinmux(SCU_PINMUX_CPLD_TDI, SCU_GPIO_NOPULL | SCU_CONF_FUNCTION0);
-	
-	gpio_input(&gpio_cpld_tdo);
-	gpio_input(&gpio_cpld_tck);
-	gpio_input(&gpio_cpld_tms);
-	gpio_input(&gpio_cpld_tdi);
-	
+	jtag_setup();
+
 	/* Configure SCU Pin Mux as GPIO */
 	scu_pinmux(SCU_PINMUX_LED1, SCU_GPIO_NOPULL);
 	scu_pinmux(SCU_PINMUX_LED2, SCU_GPIO_NOPULL);