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--- jtag [2016/02/12 09:59] – add st-link v2 stm32 pinout kingkevin
+++ jtag [2016/02/17 10:22] – fix JTAG to SWJ, restructure kingkevin
@@ Line 1: / Line 1: @@
-Here I will describe my experiences with JTAG and how I use it.
+JTAG is a technology to test integrated circuits, mostly micro-controllers and CPUs.
+It allows to do hardware debugging: read/write memory, control I/Os, and debug running code.\\
-JTAG is a technology to test electronics.
+SWD is a more modern version of JTAG and only requires 2 pins instead of 4[+1].\\
-It allows to do hardware debugging: test I/O, flash firmwares, step through assembly code, ...
+SWJ is a combination of Serial Wire Debug (SWD) and JTAG.
+But they provide the same logical functions.
 On one side this functionality must be included in the target device.
-Most 32 bits micro-controllers and SoCs have it.\\
+The Debug Port is often called JTAG-DP for JTAG and SW-DP for SWD.
-On the other side you need a JTAG adapter so the host can speak to the device using the JTAG protocol.
+SWJ capable device include and often combine both, as the SWD signal pins SWDIO and SWCLK re-use the JTAG signal pin JTMS and JTCK (backwards compatible).
-JTAG adapters can go from cheap (<5$) to expensive (>1000$), depending on the quality of the hardware and software.
-===== JTAG adapters =====
+Most 32 bits micro-controllers and SoCs have one of both (or both).\\
+On the other side you need a SWJ adapter so the host can speak to the device using the JTAG and/or SWD protocol.
+SWJ adapters can go from cheap (<5$) to expensive (>1000$), depending on the quality of the hardware and software.
-These are the main JTAG adapters I am using.
+====== SWJ adapters ======
-==== ST-Link v2 (clone) ====
+These are the main SWJ adapters I am using.
+===== ST-Link v2 =====
 The [[http://www.st.com/web/catalog/tools/FM146/CL1984/SC724/SS1677/PF251168|ST-LINK/V2]] is from STMicroelectronics, and is very convenient to flash their STM8 and STM32 micro-controllers, such as the [[stm32f1xx|STM32 F1 series]].
+It supports JTAG, SWD, and SWIM (for STM8).
+These SWJ adapters are based STM32F1xx ARM Cortex M3 micro-controllers.
+And ironically enough I in turn use them to program and debug STM32F1xx ARM Cortex M3 micro-controllers.
+First add the rules for normal users to be able to access the device (udev rule based on the VID and PID shown by lsusb).
+This has only to be done once, before the device is plugged in to be used:
+<code bash>
+echo -n 'ST-Link V2 SWJ adapter' | sudo tee -a /etc/udev/rules.d/60-st-linkv2.rules
+echo -n 'ATTR{idVendor}=="0483", ATTR{idProduct}=="3748", MODE="0666"' | sudo tee -a /etc/udev/rules.d/60-st-linkv2.rules
+sudo udevadm control --reload-rules
+</code>
+To connect to STM32F1xx ARM Cortex M3 micro-controllers I use OpenOCD:
+<code bash>
+openocd --file interface/stlink-v2.cfg --file target/stm32f1x.cfg
+Open On-Chip Debugger 0.10.0-dev-00189-g554313b (2016-01-12-10:52)
+Licensed under GNU GPL v2
+For bug reports, read
+	http://openocd.org/doc/doxygen/bugs.html
+Info : auto-selecting first available session transport "hla_swd". To override use 'transport select <transport>'.
+Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
+adapter speed: 1000 kHz
+adapter_nsrst_delay: 100
+none separate
+Info : Unable to match requested speed 1000 kHz, using 950 kHz
+Info : Unable to match requested speed 1000 kHz, using 950 kHz
+Info : clock speed 950 kHz
+Info : STLINK v2 JTAG v17 API v2 SWIM v4 VID 0x0483 PID 0x3748
+Info : using stlink api v2
+Info : Target voltage: 3.534945
+Info : stm32f1x.cpu: hardware has 6 breakpoints, 4 watchpoints
+</code>
+I am using cheap clones.
+==== BAITE ====
+The first clone is a [[http://www.aliexpress.com/item/Free-Shipping-1SET-ST-Link-st-link-V2-for-STM8S-STM8L-STM32-Cortex-M0-Cortex-M3/1758613434.html|BAITE]] ST-Link V2.
+It supports JTAG, SWD, and SWIM (for STM8).
-I have two cheap clones:
-  * one from [[http://www.aliexpress.com/item/Free-Shipping-1SET-ST-Link-st-link-V2-for-STM8S-STM8L-STM32-Cortex-M0-Cortex-M3/1758613434.html|BAITE]]
 {{:jtag:dsc02404.jpg?0x100|device front}}
 {{:jtag:dsc02405.jpg?0x100|device back}}
@@ Line 25: / Line 69: @@
 {{:jtag:st-link_v2_baite.svg?0x100|pinout}}
+STM32F103C8 connection:
 ^ STM32F103C8 signal ^ STM32F103C8 pin ^ adapter pin ^ adapter signal ^
 | PA7 | 17 | 1 | JRST |
@@ Line 41: / Line 86: @@
 the adapter pins are protected with a 220 ohms resistor.
-  * one [[http://www.aliexpress.com/item/Hot-Sale-1PCS-ST-LINK-Stlink-ST-Link-V2-Mini-STM8-STM32-Simulator-Download-Programmer-Programming/32343514985.html|more generic]]
+==== aluminium ====
+This [[http://www.aliexpress.com/item/Hot-Sale-1PCS-ST-LINK-Stlink-ST-Link-V2-Mini-STM8-STM32-Simulator-Download-Programmer-Programming/32343514985.html|one]] comes in aluminium case.
+It supports SWD, and SWIM (for STM8), but not JTAG.
+They replaced the additional JTAG pins with power pins.
 {{:jtag:dsc02407.jpg?0x100|device front}}
 {{:jtag:dsc02408.jpg?0x100|device back}}
@@ Line 47: / Line 97: @@
 {{:jtag:dsc02410.jpg?0x100|PCB back}}
+STM32F103C8 connection:
 ^ STM32F103C8 signal ^ STM32F103C8 pin ^ adapter pin ^ adapter signal ^
 | PB6 | 42 | 1 | RST |
@@ Line 60: / Line 111: @@
 | PA9 | 30 | current source  | LED |
-These devices use the Serial Wire Debug (SWD) protocol.
+===== Altera USB-Blaster =====
-This is newer variant of JTAG which requires only 2 signal lines instead of 4+.
-But but aware, they both have different pinouts on the connector.
-The second one offers 2 more power ports at the expense of JTAG TDI and TDO/SWO.
-These JTAG adapters are based STM32F1xx ARM Cortex M3 micro-controllers.
-And ironically enough I in turn use them to program and debug STM32F1xx ARM Cortex M3 micro-controllers.
-First add the rules for normal users to be able to access the device (udev rule based on the VID and PID shown by lsusb).
-This has only to be done once, before the device is plugged in to be used:
-<code bash>
-echo -n 'STM32F1xx ARM Cortex M3 micro-controllers' | sudo tee -a /etc/udev/rules.d/60-st-linkv2.rules
-echo -n 'ATTR{idVendor}=="0483", ATTR{idProduct}=="3748", MODE="0666"' | sudo tee -a /etc/udev/rules.d/60-st-linkv2.rules
-sudo udevadm control --reload-rules
-</code>
-To connect to STM32F1xx ARM Cortex M3 micro-controllers I use OpenOCD:
-<code bash>
-openocd --file interface/stlink-v2.cfg --file target/stm32f1x.cfg
-Open On-Chip Debugger 0.10.0-dev-00189-g554313b (2016-01-12-10:52)
-Licensed under GNU GPL v2
-For bug reports, read
-	http://openocd.org/doc/doxygen/bugs.html
-Info : auto-selecting first available session transport "hla_swd". To override use 'transport select <transport>'.
-Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
-adapter speed: 1000 kHz
-adapter_nsrst_delay: 100
-none separate
-Info : Unable to match requested speed 1000 kHz, using 950 kHz
-Info : Unable to match requested speed 1000 kHz, using 950 kHz
-Info : clock speed 950 kHz
-Info : STLINK v2 JTAG v17 API v2 SWIM v4 VID 0x0483 PID 0x3748
-Info : using stlink api v2
-Info : Target voltage: 3.534945
-Info : stm32f1x.cpu: hardware has 6 breakpoints, 4 watchpoints
-</code>
-==== Altera USB-Blaster (clone) ====
 The [[https://www.buyaltera.com/PartDetail?partId=1212940|USB-Blaster]] is from Altera.
@@ Line 188: / Line 201: @@
 </code>
-==== SEGGER J-Link (clone) ====
+===== SEGGER J-Link =====
 The [[http://www.aliexpress.com/item/FREE-SHIPPING-V8-ARM-Emulator-supports-ARM7-ARM9-ARM11-Cortex-M3-core-ADS-IAR-STM32-Emulator/32262570128.html|O-Link-ARM V8]] is a [[https://www.segger.com/jlink_base.html|SEGGER J-Link]] clone.
@@ Line 199: / Line 212: @@
 That makes it the most complete JTAG adapter I have.
-===== tricks =====
+====== tricks ======
-==== scan chain ====
+===== scan chain =====
 JTAG devices are called Test Access Points (TAP).