diff --git a/src/platforms/hosted/jlink.c b/src/platforms/hosted/jlink.c
index caf8bf9..d1d1220 100644
--- a/src/platforms/hosted/jlink.c
+++ b/src/platforms/hosted/jlink.c
@@ -40,14 +40,19 @@
 #define USB_VID_SEGGER_0105  0x0105
 #define USB_VID_SEGGER_1020  0x1020
 
+static uint32_t emu_caps;
+static uint32_t emu_speed_kHz;
+static uint16_t emu_min_divisor;
+static uint16_t emu_current_divisor;
+
 static void jlink_print_caps(bmp_info_t *info)
 {
 	uint8_t cmd[1] = {CMD_GET_CAPS};
 	uint8_t res[4];
 	send_recv(info->usb_link, cmd, 1, res, sizeof(res));
-	uint32_t caps = res[0] | (res[1] << 8) | (res[2] << 16) | (res[3] << 24);
-	DEBUG_INFO("Caps %" PRIx32 "\n", caps);
-	if (caps & JLINK_CAP_GET_HW_VERSION) {
+	emu_caps = res[0] | (res[1] << 8) | (res[2] << 16) | (res[3] << 24);
+	DEBUG_INFO("Caps %" PRIx32 "\n", emu_caps);
+	if (emu_caps & JLINK_CAP_GET_HW_VERSION) {
 		uint8_t cmd[1] = {CMD_GET_HW_VERSION};
 		send_recv(info->usb_link, cmd, 1, NULL, 0);
 		send_recv(info->usb_link, NULL, 0, res, sizeof(res));
@@ -57,13 +62,15 @@ static void jlink_print_caps(bmp_info_t *info)
 }
 static void jlink_print_speed(bmp_info_t *info)
 {
-	uint8_t cmd[1] = {CMD_GET_SPEED};
+	uint8_t cmd[1] = {CMD_GET_SPEEDS};
 	uint8_t res[6];
 	send_recv(info->usb_link, cmd, 1, res, sizeof(res));
-	uint32_t speed = res[0] | (res[1] << 8) | (res[2] << 16) | (res[3] << 24);
-	double freq_mhz = speed / 1000000.0;
-	uint16_t divisor = res[4] | (res[5] << 8);
-	DEBUG_INFO("Emulator speed %3.1f MHz, Mindiv %d\n", freq_mhz, divisor);
+	emu_speed_kHz = (res[0] | (res[1] << 8) | (res[2] << 16) | (res[3] << 24)) /
+					 1000;
+	emu_min_divisor = res[4] | (res[5] << 8);
+	DEBUG_INFO("Emulator speed %d kHz, Mindiv %d%s\n", emu_speed_kHz,
+			   emu_min_divisor,
+			   (emu_caps & JLINK_CAP_GET_SPEEDS) ? "" : ", fixed");
 }
 
 static void jlink_print_version(bmp_info_t *info)
@@ -98,8 +105,8 @@ static void jlink_print_interfaces(bmp_info_t *info)
 static void jlink_info(bmp_info_t *info)
 {
 	jlink_print_version(info);
-	jlink_print_speed(info);
 	jlink_print_caps(info);
+	jlink_print_speed(info);
 	jlink_print_interfaces(info);
 }
 
@@ -214,7 +221,7 @@ int jlink_init(bmp_info_t *info)
 const char *jlink_target_voltage(bmp_info_t *info)
 {
         uint8_t cmd[1] = {CMD_GET_HW_STATUS};
-        uint8_t res[8];
+		uint8_t res[8];
         send_recv(info->usb_link, cmd, 1, res, sizeof(res));
         uint16_t mVolt = res[0] | (res[1] << 8);
         static char ret[7];
@@ -238,3 +245,27 @@ bool jlink_srst_get_val(bmp_info_t *info) {
         send_recv(info->usb_link, cmd, 1, res, sizeof(res));
         return !(res[6]);
 }
+
+void jlink_max_frequency_set(bmp_info_t *info, uint32_t freq)
+{
+	if (!(emu_caps &  JLINK_CAP_GET_SPEEDS))
+		return;
+	if (!info->is_jtag)
+		return;
+	uint16_t freq_kHz = freq /1000;
+	uint16_t divisor = (emu_speed_kHz + freq_kHz - 1) / freq_kHz;
+	if (divisor < emu_min_divisor)
+		divisor = emu_min_divisor;
+	emu_current_divisor = divisor;
+	uint16_t speed_kHz = emu_speed_kHz / divisor;
+	uint8_t cmd[3] = {CMD_SET_SPEED, speed_kHz & 0xff, speed_kHz >> 8};
+	DEBUG_WARN("Set Speed %d\n", speed_kHz);
+	send_recv(info->usb_link, cmd, 3, NULL, 0);
+}
+
+uint32_t jlink_max_frequency_get(bmp_info_t *info)
+{
+	if ((emu_caps & JLINK_CAP_GET_SPEEDS) && (info->is_jtag))
+		return (emu_speed_kHz * 1000L)/ emu_current_divisor;
+	return FREQ_FIXED;
+}
diff --git a/src/platforms/hosted/jlink.h b/src/platforms/hosted/jlink.h
index c79b868..5504c67 100644
--- a/src/platforms/hosted/jlink.h
+++ b/src/platforms/hosted/jlink.h
@@ -24,8 +24,9 @@
 
 /** @cond PRIVATE */
 #define CMD_GET_VERSION         0x01
+#define CMD_SET_SPEED           0x05
 #define CMD_GET_HW_STATUS       0x07
-#define CMD_GET_SPEED           0xc0
+#define CMD_GET_SPEEDS          0xc0
 #define CMD_GET_SELECT_IF       0xc7
 #define CMD_HW_JTAG3            0xcf
 #define CMD_HW_RESET0           0xdc
@@ -37,7 +38,8 @@
 #define JLINK_IF_GET_ACTIVE    0xfe
 #define JLINK_IF_GET_AVAILABLE 0xff
 
-#define JLINK_CAP_GET_HW_VERSION  2
+#define JLINK_CAP_GET_SPEEDS     (1 <<  9)
+#define JLINK_CAP_GET_HW_VERSION (1 <<  1)
 #define JLINK_IF_JTAG             1
 #define JLINK_IF_SWD              2
 
@@ -53,13 +55,54 @@ int jlink_jtagtap_init(bmp_info_t *info, jtag_proc_t *jtag_proc) {return 0;};
 const char *jlink_target_voltage(bmp_info_t *info) {return "ERROR";};
 void jlink_srst_set_val(bmp_info_t *info, bool assert) {};
 bool jlink_srst_get_val(bmp_info_t *info) {return true;};
+void jlink_max_frequency_set(bmp_info_t *info, uint32_t freq) {};
+uint32_t jlink_max_frequency_get(bmp_info_t *info) {return 0;};
 # pragma GCC diagnostic pop
 #else
+/** Device capabilities. (from openocd*/
+enum jaylink_device_capability {
+        /** Device supports retrieval of the hardware version. */
+        JAYLINK_DEV_CAP_GET_HW_VERSION = 1,
+        /** Device supports adaptive clocking. */
+        JAYLINK_DEV_CAP_ADAPTIVE_CLOCKING = 3,
+        /** Device supports reading configuration data. */
+        JAYLINK_DEV_CAP_READ_CONFIG = 4,
+        /** Device supports writing configuration data. */
+        JAYLINK_DEV_CAP_WRITE_CONFIG = 5,
+        /** Device supports retrieval of target interface speeds. */
+        JAYLINK_DEV_CAP_GET_SPEEDS = 9,
+        /** Device supports retrieval of free memory size. */
+        JAYLINK_DEV_CAP_GET_FREE_MEMORY = 11,
+        /** Device supports retrieval of hardware information. */
+        JAYLINK_DEV_CAP_GET_HW_INFO = 12,
+        /** Device supports the setting of the target power supply. */
+        JAYLINK_DEV_CAP_SET_TARGET_POWER = 13,
+        /** Device supports target interface selection. */
+        JAYLINK_DEV_CAP_SELECT_TIF = 17,
+        /** Device supports retrieval of counter values. */
+        JAYLINK_DEV_CAP_GET_COUNTERS = 19,
+        /** Device supports capturing of SWO trace data. */
+        JAYLINK_DEV_CAP_SWO = 23,
+        /** Device supports file I/O operations. */
+        JAYLINK_DEV_CAP_FILE_IO = 26,
+        /** Device supports registration of connections. */
+        JAYLINK_DEV_CAP_REGISTER = 27,
+        /** Device supports retrieval of extended capabilities. */
+        JAYLINK_DEV_CAP_GET_EXT_CAPS = 31,
+        /** Device supports EMUCOM. */
+        JAYLINK_DEV_CAP_EMUCOM = 33,
+        /** Device supports ethernet connectivity. */
+        JAYLINK_DEV_CAP_ETHERNET = 38
+};
+
+
 int jlink_init(bmp_info_t *info);
 int jlink_swdp_scan(bmp_info_t *info);
 int jlink_jtagtap_init(bmp_info_t *info, jtag_proc_t *jtag_proc);
 const char *jlink_target_voltage(bmp_info_t *info);
 void jlink_srst_set_val(bmp_info_t *info, bool assert);
 bool jlink_srst_get_val(bmp_info_t *info);
+void jlink_max_frequency_set(bmp_info_t *info, uint32_t freq);
+uint32_t jlink_max_frequency_get(bmp_info_t *info);
 #endif
 #endif
diff --git a/src/platforms/hosted/platform.c b/src/platforms/hosted/platform.c
index 9b1638e..5e55603 100644
--- a/src/platforms/hosted/platform.c
+++ b/src/platforms/hosted/platform.c
@@ -339,10 +339,21 @@ void platform_max_frequency_set(uint32_t freq)
 	case BMP_TYPE_STLINKV2:
 		stlink_max_frequency_set(&info, freq);
 		break;
+	case BMP_TYPE_JLINK:
+		jlink_max_frequency_set(&info, freq);
+		break;
 	default:
 		DEBUG_WARN("Setting max SWJ frequency not yet implemented\n");
 		break;
 	}
+	uint32_t max_freq = platform_max_frequency_get();
+	if (max_freq == FREQ_FIXED)
+		DEBUG_INFO("Device has fixed frequency for %s\n",
+				   (info.is_jtag) ? "JTAG" : "SWD" );
+	else
+		DEBUG_INFO("Speed set to %7.4f MHz for %s\n",
+				   platform_max_frequency_get() / 1000000.0,
+				   (info.is_jtag) ? "JTAG" : "SWD" );
 }
 
 uint32_t platform_max_frequency_get(void)
@@ -357,6 +368,8 @@ uint32_t platform_max_frequency_get(void)
 		return libftdi_max_frequency_get();
 	case BMP_TYPE_STLINKV2:
 		return stlink_max_frequency_get(&info);
+	case BMP_TYPE_JLINK:
+		return jlink_max_frequency_get(&info);
 	default:
 		DEBUG_WARN("Reading max SWJ frequency not yet implemented\n");
 		break;