OLIMEX ARM-JTAG-EW User manual

ARM-JTAG-EW
User Manual
All boards produced by Olimex are ROHS compliant
Rev.B, March 2009
Copyr ght(c) 2009, OLIMEX Ltd, All r ghts reserved

1. Introduct on
ARM-JTAG-EW is a JTAG probe for debugging ARM microcontrollers. It s a
product by joined efforts of Olimex and IAR Systems, aiming not just to
release yet another fast USB JTAG compatible with Embedded Workbench,
but to make low cost JTAG with features available only in the expensive
logic analyzers. For this purpose ARM-JTAG-EW offers external
breakpoints in addition to ordinary software and hardware ones. User can
configure ARM-JTAG-EW to stop the target program on an external trigger,
defined by target power consumption, rising/falling edge of external
signals, analogue signal window value.
ARM-JTAG-EW emulates the IAR Systems J-LINK API so it works like
normal J-LINK debugger, yet it adds some unique features which are
available only in the very high end and expensive debugger tools on the
market.
1.1. Hardware Features
- JTAG connector with ARM 2x10 pin layout for target programming and
debugging
- supports ARM targets working in voltage range 2.0–5.0V DC 1
- USB full-speed connection to the PC
- bi-color status LED
- can provide 5.0V DC power to target via pin 19 of the JTAG connector
- measurement of target current consumption
- measurement of target MCU voltage and output voltage (pins 1 and 19
of the JTAG connector)
- JTAG and SWD TCK frequency range 6kHz – 12MHz
- SWO frequency range 1kHz – 3MHz
- dimensions 50x40 mm (2x1.6") + 20 cm (8") JTAG cable
1.2. Software Features
- DLL mostly compatible with original jlinkarm.dll from IAR-EW2
- works with IAR Embedded Workbench 5.30 from IAR Systems
- supports ARM7TDMI targets (e.g. SAM7, LPC2000, STR7)
- supports Cortex M3 targets (e.g. STM32, LPC1000)
- ability to put “external” breakpoints that trigger on a user-defined event
- external event sources are the target MCU voltage, target supply voltage
and target consumption current
1 ARM-JTAG-EW outputs have 3.3V levels and will work with 5V targets that have TTL-level inputs.
2 DLL compatible means that we supply our own jlinkarm.dll. The original IAR-EW DLL will not work
with the ARM-JTAG-EW device because ARM-JTAG-EW and IAR J-Link use different USB
protocols.

1.3. Electrostatic Warning
The ARM-JTAG-EW device is shipped in protective anti-static packaging.
The device must not be subject to high electrostatic potentials. General
practice for working with static sensitive devices should be applied when
working with this device.
1.4. ARM-J AG-EW Usage Requirements
Cables: 1.8 meter USB A-B cable.
Software: EW-ARM 5.30 from IAR Systems AB
2. Hardware
2.1. USB Connector
ARM-JTAG-EW has a standard USB device connector that requires a
standard USB A-B cable for connecting to a PC.
2.2. J AG Connector
The JTAG connector pin description is given below.
Pin
№
Signal Direc
tion3
Descri tion
1 UTG I Target reference voltage. Target board must connect
3 Pin direction is from the side of ARM-JTAG-EW. I stands for Input (Target to ARM-JTAG-EW), and
O for output (ARM-JTAG-EW to Target).

Pin
№
Signal Direc
tion
Descri tion
it to the MCU supply line that drives the JTAG pins.
Input has resistance 4 kΩ.
2 UTG,2 I Target board should connect it to the MCU supply
line that drives the JTAG pins.
3 nTRST O
(open
drain)
Target JTAG TAP reset. ARM-JTAG-EW has 100 Ω
resistor in series with this output. Driven as open
drain output.
4 GND - Ground.
5 TDI O Target JTAG Data IN. ARM-JTAG-EW has 100 Ω
resistor in series with this output.
6 GND - Ground.
7 TMS/
SWDIO
O Target JTAG Mode Select and Serial Wire Data
Input/Output. ARM-JTAG-EW has 100 Ω resistor in
series with this output.
8 GND - Ground.
9 TCK/
SWCLK
O Target JTAG clock and Serial Wire Clock. ARM-
JTAG-EW has 100 Ω resistor in series with this
output.
10 GND - Ground.
11 RTCK I Target JTAG return clock. ARM-JTAG-EW has 100
Ω resistor in series with this input.
12 GND - Ground.
13 TDO/
SWO
I Target JTAG data output and Serial Wire Output.
ARM-JTAG-EW has 100 Ω resistor in series with
this input.
14 GND - Ground.
15 nSRST O
(open
drain)
Target system reset. ARM-JTAG-EW has 100 Ω
resistor in series with this output. Driven as open
drain output.
16 GND - Ground.
17 NC - Not connected in ARM-JTAG-EW.
18 GND - Ground.
19 UTGPWR O Target power supply voltage provided by ARM-JTAG-
EW. Supply is taken from USB and is switched by a
MOSFET transistor. There is 4 kΩ resistor
connected between this pin and ground.
20 GND - Ground.
2.3. Providing arget Power Via J AG Connector
By default ARM-JTAG-EW connects the USB supply voltage to pin 19 of
the JTAG connector via MOSFET switch. Depending on the current
consumption and the used USB host and hubs the supplied voltage can
vary between 4.0V and 5.25V.

WARNING: In case of a target current consumption exceeding 400 mA,
including a short circuit on the target board, ARM-JTAG-EW will
shutdown its power output UTGPWR. Some USB hosts and hubs, however,
have faster short-circuit-detectors and will shutdown the power to ARM-
JTAG-EW before it has a chance to react.
Target power can be turned ON and OFF using the C-SPY macro
__jlinkExecCommand() like this:
//Turn power ON
execUserPreload() {
__jlinkExecCommand( SupplyPower = 1 );
}
//Turn power OFF
execUserPreload() {
__jlinkExecCommand( SupplyPower = 0 );
}
2.4. LED Indication
ARM-JTAG-EW has a single dual color LED. Its states are shown below.
Slow blinking is with a period of 1s, and fast blinking is with a period of
128ms.
LED State Descri tion
OFF ARM-JTAG-EW is not connected to USB, or it is
in USB suspended state.
Slow RED blinking No target connected.
GREEN constantly on Target connected.
Fast RED blinking Target error caused by target current
overconsumption or MCU voltage out of
bounds.
GREEN blinking USB communication is taking place.
Slow blinking sequence
GREEN→RED→OFF
ARM-JTAG-EW is in boot loader mode.
3. Software Installat on
Please follow the following procedure exactly in the order it is written:
1. Install the Visual Studio 2008 SP1 Redistributable Package
vcredist_x86.exe freely available from Microsoft:
http://www.microsoft.com/downloads/details.aspx?
familyid=A5C84275-3B97-4AB7-
A40D-3802B2AF5FC2&displaylang=en
2. Install the .NET framework available freely from Microsoft: http://
msdn2.microsoft.com/en-us/netframework/default.aspx.

3. Download the ARM-JTAG-EW software package from
http://www.olimex.com/dev. Extract it to a temporary directory on
your hard drive using the password found in the box along with the
ARM-JTAG-EW device.
4. Plug ARM-JTAG-EW in your PC and wait Windows to ask you for
drivers.

5. Next point the driver installation wizard to the “\driver”
subdirectory of the previously extracted software package.
6. If Windows complains that the driver is not signed then click to
continue and ignore the warning.
4. Us ng ARM-JTAG-EW w th IAR-EW 5.30 ARM
Using ARM-JTAG-EW under IAR-EW is straightforward. ARM-JTAG-EW
behaves just like IAR J-Link, provided that the original IAR-EW jlinkarm.dll
is replaced by ARM-JTAG-EW s one.
4.1. Installing ARM-J AG-EW DLL
Download the ARM-JTAG-EW software package from
http://www.olimex.com/dev. Extract it to a temporary directory on your
hard drive using the password found in the box along with the ARM-JTAG-
EW device. The software package contains the file jlinkarm.dll. Find it and
copy it to the IAR-ARM “arm\bin” directory, like this:
C:\> copy c:\arm-jtag-ew-1.0.0.0\jlinkarm.dll "c:\Program Files\IAR
ystems\Embedded Workbench 5.20\ARM\bin"
Overwrite c:\Program Files\IAR Systems\Embedded Workbench
5.20\ARM\bin\jlinkarm.dll? (Yes/No/All): yes
1 file(s) copied.

5. External event breakpo nts
5.1. Overview
ARM-JTAG-EW has the ability to halt the target CPU upon detecting an
external event like a current/voltage spike/drop, external input trigger,
external input pulse detection.
External Breakpoints Block Diagram is given on page 9.
External events can be defined with a simple C-like expression like this
(see page 9 for more information):
(3000<U_tg && U_tg<3600)
So when ARM-JTAG-EW detects that UTG>3000mV AND UTG<3600mV, it
will shift a request to the target CPU to halt.
Multiple inputs can be mixed into one event:
(3000<U_tg && U_tg<3600) || I_tgpwr>200
WARNING: There is always some time between an actual event and the
corresponding action by ARM-JTAG-EW. Due to the limited sampling rate
of analogue signals, ARM-JTAG-EW cannot detect instantly changes on its
inputs. Also note that shifting the JTAG sequence for requesting a target
CPU halt also takes time, depending on the TCK frequency. Heavy USB
traffic can also influence the response time.

5.2. Formal event syntax
The grammar for defining events is very C-like. The following identifiers are
recognized:
Identifier Ty e Descri tion
U_tg analogue Target power voltage. Expressed in mV.
I_tgpwr analogue Target current consumption. Expressed in mA.
true boolean Constant high (one)
false boolean Constant low (zero)
Analogue variables can only be compared to constant values (mV for
voltages, mA for currents). Every analogue variable can be compared
against at most two constants, due to the availability of only two
comparators in firmware.
A formal definition of the grammar is given below.
PRIMARY_BOOLEAN ::= 'true' | 'false' | ('(' EXPR ')')
PRIMARY_ANALOG ::= ['0' '9']+ | 'U_tg' | 'I_tgpwr'
RELATIONAL_ANALOG ::= (PRIMARY_ANALOG '<' PRIMARY_ANALOG)
Illustration 1: External Breakpoints Block Diagram
UTG
boolean
function
defined
by a
Look-Up
Table
UTG,threshold2
UTG,threshold1
hardware inputs
to ARM- TAG-EW
ITGPWR
ITGPWR,threshold2
ITGPWR,threshold1
comparators
implemented
via firmware
request to
halt target

| (PRIMARY_ANALOG '<=' PRIMARY_ANALOG)
| (PRIMARY_ANALOG '>' PRIMARY_ANALOG)
| (PRIMARY_ANALOG '>=' PRIMARY_ANALOG)
UNARY_EXPR ::= RELATIONAL_ANALOG | PRIMARY_BOOLEAN | ('!'+ PRIMARY_BOOLEAN)
EQUALITY_EXPR ::= UNARY_EXPR (('==' UNARY_EXPR) | ('!=' UNARY_EXPR))*
AND_EXPR ::= EQUALITY_EXPR ('&&' EQUALITY_EXPR)*
XOR_EXPR ::= AND_EXPR ('^^' AND_EXPR)*
OR_EXPR ::= XOR_EXPR ('||' XOR_EXPR)*
EXPR ::= OR_EXPR
5.3. Setting events in IAR-EW and C-SPY
You will need to setup a C-SPY macro file. Please consult the IAR-EW
documentation for more information.
Use the __jlinkExecCommand() C-SPY macro with first argument “extbkpt”
to set an external event expression. For example, if you want to halt the
target if it consumes more than 100mA write the following in your C-SPY
macro file:
execUserPreload() {
__jlinkExecCommand( extbkpt I_tgpwr>100 );
}
If you want to halt the target if its voltage goes out of the [3.0V – 3.6V]
range then you can write a macro like this:
execUserPreload() {
__jlinkExecCommand( extbkpt !(3000<U_tg && U_tg<3600) );
}
The vmeter command can be used to get the current state of the event
inputs:
__jlinkExecCommand( vmeter );
An example output of this command is:
Fri Feb 06 13:18:53 2009: J-Link Exec Command: VMETER: U_tg=3.254000
V, U_aux=0.000000 V, U_tgpwr=4.885000 V, I_tgpwr=17.000001 mA, D1=1,
target power enabled and OK
Fri Feb 06 13:18:53 2009: Error in C:\MyProject\test.mac at line 9, col 23:
Operation error.
Fri Feb 06 13:18:53 2009: Error while calling macro execUserPreload
NOTE: As seen above, IAR C-SPY reports an error when calling the vmeter
command. You can safely ignore it.