pub struct JayLink { /* private fields */ }
Expand description
A handle to a J-Link USB device.
This is the main interface type of this library. There are multiple ways of obtaining an instance of it:
JayLink::open_by_serial
: Either opens the only J-Link device connected to the computer, or opens a specific one by its serial number. Recommended for applications that interact with one J-Link device only (ie. most of them).JayLink::open_usb
: Opens a specific J-Link device according to the givenUsbDeviceInfo
. Also seescan_usb
.
Implementations
Opens an attached J-Link device by its serial number.
If serial
is None
, this will open the only attached J-Link device, and return an error
of type ErrorKind::MultipleDevicesFound
when more than one is attached. This is usually
the desired behavior of robust applications.
Note: Probes remember their selected interfaces between reconnections, so it is
recommended to always call JayLink::select_interface
after opening a probe.
Opens a specific J-Link USB device.
Note: Probes remember their selected interfaces between reconnections, so it is
recommended to always call JayLink::select_interface
after opening a probe.
Returns the manufacturer string stored in the device descriptor.
Returns the product string stored in the device descriptor.
Returns the serial number string stored in the device descriptor.
This serial number string can be passed to JayLink::open_by_serial
to open a specific
J-Link device.
Reads the firmware version string from the device.
Reads the hardware version from the device.
This requires the probe to support Capability::GetHwVersion
.
Reads the probe’s communication speed information about the currently selected interface.
Supported speeds may differ between Interface
s, so the right interface needs to be
selected for the returned value to make sense.
This requires the probe to support Capability::SpeedInfo
.
Reads the probe’s SWO capture speed information.
This requires the probe to support Capability::Swo
.
Reads the maximum mem block size in Bytes.
This requires the probe to support Capability::GetMaxBlockSize
.
Returns the capabilities advertised by the probe.
Returns the set of target interfaces supported by the probe.
Reads the currently selected target interface.
Note: There is no guarantee that the returned interface is actually supported (ie. it
might not be in the list returned by JayLink::available_interfaces
). In particular, some
embedded J-Link probes start up with JTAG selected, but only support SWD.
Selects the interface to use for talking to the target MCU.
Switching interfaces will reset the configured transfer speed, so JayLink::set_speed
needs to be called after select_interface
.
This requires the probe to support Capability::SelectIf
.
Note: Selecting a different interface may cause the J-Link to perform target I/O!
Changes the state of the TMS / SWDIO pin (pin 7).
The pin will be set to the level of VTref
if tms
is true
, and to GND if it is false
.
Note: On some hardware, detaching VTref
might not affect the internal reading, so the
old level might still be used afterwards.
Changes the state of the TDI / TX pin (pin 5).
The pin will be set to the level of VTref
if tdi
is true
, and to GND if it is false
.
Note: On some hardware, detaching VTref
might not affect the internal reading, so the
old level might still be used afterwards.
Changes the state of the (n)TRST pin (pin 3).
The pin will be set to the level of VTref
if trst
is true
, and to GND if it is
false
.
Note: On some hardware, detaching VTref
might not affect the internal reading, so the
old level might still be used afterwards.
Note: Some embedded J-Link probes may not expose this pin or may not allow controlling it using this function.
Changes the state of the RESET pin (pin 15).
RESET is an open-collector / open-drain output. If reset
is true
, the output will float.
If reset
is false
, the output will be pulled to ground.
Note: Some embedded J-Link probes may not expose this pin or may not allow controlling it using this function.
Resets the target’s JTAG TAP controller by temporarily asserting (n)TRST (Pin 3).
This might not do anything if the pin is not connected to the target. It does not affect non-JTAG target interfaces.
Resets the target by temporarily asserting the RESET pin (pin 15).
This might not do anything if the RESET pin is not connected to the target.
Sets the target communication speed.
If speed
is set to SpeedConfig::ADAPTIVE
, then the probe has to support
Capability::AdaptiveClocking
. Note that adaptive clocking may not work for all target
interfaces (eg. SWD).
When the selected target interface is switched (by calling JayLink::select_interface
, or
any API method that automatically selects an interface), the communication speed is reset to
some unspecified default value.
Reads the target voltage measured on the VTref
pin, in millivolts.
In order to use the J-Link, this voltage must be present, since it will be used as the level of the I/O signals to the target.
Enables or disables the 5V Power supply on pin 19.
This requires the probe to support Capability::SetKsPower
.
Note: The startup state of the power supply can be configured in non-volatile memory.
Note: Some embedded J-Links may not provide this feature or do not have the 5V supply routed to a pin. In that case this function might return an error, or it might return successfully, but without doing anything.
Note: The 5V supply is protected against overcurrent. Check the device manual for more information on this.
pub fn jtag_io<'a, M, D>(&'a mut self, tms: M, tdi: D) -> Result<BitIter<'a>> where
M: IntoIterator<Item = bool>,
D: IntoIterator<Item = bool>,
pub fn jtag_io<'a, M, D>(&'a mut self, tms: M, tdi: D) -> Result<BitIter<'a>> where
M: IntoIterator<Item = bool>,
D: IntoIterator<Item = bool>,
Performs a JTAG I/O operation.
This will shift out data on TMS
(pin 7) and TDI
(pin 5), while reading data shifted
into TDO
(pin 13).
The data received on TDO
is returned to the caller as an iterator yielding bool
s.
The caller must ensure that the probe is in JTAG mode by calling
JayLink::select_interface
(
Interface::Jtag
)
.
Parameters
tms
: TMS bits to transmit.tdi
: TDI bits to transmit.
Panics
This method will panic if tms
and tdi
have different lengths. It will also panic if any
of them contains more then 65535 bits of data, which is the maximum amount that can be
transferred in one operation.
pub fn swd_io<'a, D, S>(&'a mut self, dir: D, swdio: S) -> Result<BitIter<'a>> where
D: IntoIterator<Item = bool>,
S: IntoIterator<Item = bool>,
pub fn swd_io<'a, D, S>(&'a mut self, dir: D, swdio: S) -> Result<BitIter<'a>> where
D: IntoIterator<Item = bool>,
S: IntoIterator<Item = bool>,
Performs an SWD I/O operation.
This requires the probe to support Capability::SelectIf
and support for
Interface::Swd
.
The caller must ensure that the probe is in SWD mode by calling
JayLink::select_interface
(
Interface::Swd
)
.
Parameters
dir
: Transfer directions of theswdio
bits (false
= 0 = Input,true
= 1 = Output).swdio
: SWD data bits.
If dir
is true
, the corresponding bit in swdio
will be written to the target; if it is
false
, the bit in swdio
is ignored and a bit is read from the target instead.
Return Value
An iterator over the SWDIO
bits is returned. Bits that were sent to the target (where
dir
= true
) are undefined, and bits that were read from the target (dir
= false
)
will have whatever value the target sent.
Starts capturing SWO data.
This will switch the probe to SWD interface mode if necessary (required for SWO capture).
Requires the probe to support Capability::Swo
.
Parameters
mode
: The SWO data encoding mode to use.speed
: The data rate to capture at (when usingSwoMode::Uart
, this is the UART baud rate).buf_size
: The size (in Bytes) of the on-device buffer to allocate for the SWO data. You can callJayLink::read_max_mem_block
to get an approximation of the available memory on the probe.
Return Value
This returns a SwoStream
object, which can be used to directly read the captured SWO
data via std::io::Read
. If blocking reads are undesired (or the JayLink
instance
needs to be used for something else while SWO capture is in progress), the SwoStream
can be ignored and JayLink::swo_read
be used instead.
Reads captured SWO data from the probe and writes it to data
.
This needs to be called regularly after SWO capturing has been started. If it is not called
often enough, the buffer on the probe will fill up and device data will be dropped. You can
call SwoData::did_overrun
to check for this condition.
Note: the probe firmware seems to dislike many short SWO reads (as in, the probe will fall off the bus and reset), so it is recommended to use a buffer that is the same size as the on-probe data buffer.