diff --git a/tools/include/atrf.h b/tools/include/atrf.h
index fb66111..b5ffea5 100644
--- a/tools/include/atrf.h
+++ b/tools/include/atrf.h
@@ -40,6 +40,7 @@ void atrf_reset_rf(struct atrf_dsc *dsc);
 enum atrf_chip_id atrf_identify(struct atrf_dsc *dsc);
 
 int atrf_test_mode(struct atrf_dsc *dsc);
+int atrf_slp_tr(struct atrf_dsc *dsc, int on);
 int atrf_set_clkm(struct atrf_dsc *dsc, int mhz);
 
 void atrf_reg_write(struct atrf_dsc *dsc, uint8_t reg, uint8_t value);
diff --git a/tools/lib/atben.c b/tools/lib/atben.c
index 5e67787..03175ca 100644
--- a/tools/lib/atben.c
+++ b/tools/lib/atben.c
@@ -326,6 +326,20 @@ static int atben_buf_read(void *handle, void *buf, int size)
 }
 
 
+/* ----- SLP_TR ------------------------------------------------------------ */
+
+
+static void atben_slp_tr(void *handle, int on)
+{
+	struct atben_dsc *dsc = handle;
+
+	if (on)
+		PDDATS = SLP_TR;
+	else
+		PDDATC = SLP_TR;
+}
+
+
 /* ----- RF interrupt ------------------------------------------------------ */
 
 
@@ -347,6 +361,7 @@ struct atrf_driver atben_driver = {
 	.reset		= NULL,
 	.reset_rf	= atben_reset_rf,
 	.test_mode	= NULL,
+	.slp_tr		= atben_slp_tr,
 	.reg_write	= atben_reg_write,
 	.reg_read	= atben_reg_read,
 	.buf_write	= atben_buf_write,
diff --git a/tools/lib/atrf.c b/tools/lib/atrf.c
index 1d5774e..08bc6c1 100644
--- a/tools/lib/atrf.c
+++ b/tools/lib/atrf.c
@@ -149,6 +149,15 @@ int atrf_test_mode(struct atrf_dsc *dsc)
 }
 
 
+int atrf_slp_tr(struct atrf_dsc *dsc, int on)
+{
+	if (!dsc->driver->slp_tr)
+		return 0;
+	dsc->driver->slp_tr(dsc->handle, on);
+	return 1;
+}
+
+
 int atrf_set_clkm_generic(
     void (*reg_write)(void *dsc, uint8_t reg, uint8_t value),
     void *handle, int mhz)
diff --git a/tools/lib/atusb.c b/tools/lib/atusb.c
index 077e702..63bd8cb 100644
--- a/tools/lib/atusb.c
+++ b/tools/lib/atusb.c
@@ -281,6 +281,7 @@ struct atrf_driver atusb_driver = {
 	.reset		= atusb_reset,
 	.reset_rf	= atusb_reset_rf,
 	.test_mode	= atusb_test_mode,
+	.slp_tr		= NULL,	/* @@@ not yet *
 	.set_clkm	= atusb_set_clkm,
 	.reg_write	= atusb_reg_write,
 	.reg_read	= atusb_reg_read,
diff --git a/tools/lib/driver.h b/tools/lib/driver.h
index 2dbc5aa..13d1dc2 100644
--- a/tools/lib/driver.h
+++ b/tools/lib/driver.h
@@ -26,6 +26,7 @@ struct atrf_driver {
 	void (*reset)(void *dsc);
 	void (*reset_rf)(void *dsc);
 	void (*test_mode)(void *dsc);
+	void (*slp_tr)(void *dsc, int on);
 	int (*set_clkm)(void *dsc, int mhz);
 	void (*reg_write)(void *dsc, uint8_t reg, uint8_t value);
 	uint8_t (*reg_read)(void *dsc, uint8_t reg);