SEGGER J-Link-OB-RA4M2 On Board Debug Probe User Guide
- June 5, 2024
- SEGGER
Table of Contents
- SEGGER J-Link-OB-RA4M2 On Board Debug Probe
- About this document
- Chapter 1 Why J-Link OB?
- Chapter 2 Supported target CPU cores
- Chapter 3 Supported target interfaces
- Chapter 4
- CHAPTER 6 Glossary
- References
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)
- RESET (P112)
- RESET (P112)
- RESET (P112)
SEGGER J-Link-OB-RA4M2 On Board Debug Probe
Disclaimer
The information written in this document is assumed to be accurate without
guarantee. The information in this manual is subject to change for functional
or performance improvements without notice. SEGGER Microcontroller GmbH
(SEGGER) assumes no responsibility for any errors or omissions in this
document. SEGGER disclaims any warranties or conditions, express, implied or
statutory for the fitness of the product for a particular purpose. It is your
sole responsibility to evaluate the fitness of the product for any specific
use.
Copyright notice
You may not extract portions of this manual or modify the PDF file in any way
without the prior written permission of SEGGER. The software described in this
document is furnished under a license and may only be used or copied in
accordance with the terms of such a license. © 2022-2022 SEGGER
Microcontroller GmbH, Monheim am Rhein / Germany
Trademarks
Names mentioned in this manual may be trademarks of their respective
companies. Brand and product names are trademarks or registered trademarks of
their respective holders.
Contact address
SEGGER Microcontroller GmbH
Ecolab-Allee 5 D-40789 Monheim am Rhein
Germany
Tel. +49-2173-99312-0
Fax. +49-2173-99312-28
E-mail: support@segger.com
Internet: www.segger.com
Manual versions
This manual describes the current software version. If you find an error in
the manual or a problem in the software, please report it to us and we will
try to assist you as soon as possible. Contact us for further information on
topics or functions that are not yet documented.
Print date: July 18, 2022
Manual version | Revision | Date | By | Description |
---|---|---|---|---|
0.00 | 1 | 220718 | AG | Initial Version |
About this document
Assumptions
This document assumes that you already have a solid knowledge of the
following:
- The software tools used for building your application (assembler, linker, C compiler).
- The C programming language.
- The target processor.
- DOS command line.
If you feel that your knowledge of C is not sufficient, we recommend The C Programming Language by Kernighan and Richie (ISBN 0–13–1103628), which describes the standard in C programming and, in newer editions, also covers the ANSI C standard.
How to use this manual
This manual explains all the functions and macros that the product offers. It
assumes you have a working knowledge of the C language. Knowledge of assembly
programming is not required.
Typographic conventions for syntax
This manual uses the following typographic conventions:
Style | Used for |
---|---|
Body | Body text. |
Keyword | Text that you enter at the command prompt or that appears on the |
display (that is system functions, file- or pathnames).
Parameter| Parameters in API functions.
Sample| Sample code in program examples.
Sample comment| Comments in program examples.
Reference| Reference to chapters, sections, tables and figures or other
documents.
GUI Element| Buttons, dialog boxes, menu names, menu commands.
Emphasis| Very important sections.
Chapter 1 Why J-Link OB?
The J-Link on-board (J-Link OB) was designed in order to provide a low-cost,
space-saving and on-board alternative to the general J-Link, for eval board
manufacturers. J-Link OB can be used with the same software package as the
general J-Links and can be used with the same utilities (as far as the feature
set of the J-Link OB supports this)
Note It is not allowed to use J-Link-OB-RA4M2 for stand-alone emulators.
Chapter 2 Supported target CPU cores
For a list of cores supported by this J-Link OB model, please refer to here: J-Link OB Model overview
Chapter 3 Supported target interfaces
The J-Link-OB-RA4M2 supports the following target interfaces:
- JTAG
- cJTAG
- SWD
- SWO
- 1x virtual COM port (VCOM) + optional hardware flow control
Target interface pins
The J-Link-OB-RA4M2 provides the following target interface signals:
- TCK/SWCLK (P102)
- TMS/SWDIO (P101)
- TDI (P103)
- TDO/SWO (P100)
-
RESET (P112)
- TXD_VCOM (P302)
- RXD_VCOM (P301)
- CTS_VCOM (P409)
- RTS_VCOM (P408)
Which signals are required depends on what features shall be supported on the evaluation board. If support for a specific feature or interface is not required, the spare pins should be left open. For more information about which target interface requires which signals, please refer to the following sections.
Target interface JTAG
If JTAG support is required on the target hardware to be designed, the following signals need to be connected:
- TCK (P102)
- TMS (P101)
- TDI (P103)
- TDO (P100)
-
RESET (P112)
Note
TCK and TMS share functionality with the SWCLK and SWDIO pins used for the SWD
interface. So if JTAG connected on the J-Link OB, SWD is supported
automatically as well.
Target interface SWD
If SWD (+ optional SWO) support is required on the target hardware to be designed, the following signals need to be connected:
- SWCLK (P102)
- SWDIO (P101)
- SWO (P100)
-
RESET (P112)
If SWO support is not required (e.g. when the target CPU is Cortex-M0/M0+ based, which does not provide SWO support), the SWO signal can be left open.
Target interface VCOM
This J-Link OB model can support up to 1x virtual COM port (VCOM) as an optional and additional target interface. For more information about what VCOM is, please refer to JLink VCOM functionality . If VCOM (+ optional hardware flow control) support is required on the target hardware to be designed, the following signals need to be connected:
- TXD (P302)
- RXD (P301)
- CTS (P409)
- RTS (P408)
If hardware flow control support is not required, the CTS and RTS signal can be left open.
Note
VCOM is an optional feature that needs to be ordered explicitly when ordering
J-Link OB licenses.
Chapter 4
Compatible MCUs as J-Link OB host
The J-Link-OB-RA4M2 is based on the Renesas RA4M2 100 MHz, 128 KB flash, 24 KB RAM series MCUs. The following microcontrollers are compatible to this J-Link OB model: · R7FA4M2AB3CNE (512 KB flash, 48-pin QFN) Untested but pin, flash and RAM compatible:
- R7FA4M2AB3CFL (512 KB flash, 48-pin LQFP)
- R7FA4M2AB3CFM (512 KB flash, 64-pin LQFP)
- R7FA4M2AB3CFP (512 KB flash, 100-pin LQFP)
- R7FA4M2AC3CFP (384 KB flash, 100-pin LQFP)
- R7FA4M2AC3CFM (384 KB flash, 64-pin LQFP)
- R7FA4M2AC3CFL (384 KB flash, 48-pin LQFP)
- R7FA4M2AC3CNE (384 KB flash, 48-pin QFN)
- R7FA4M2AB3CFP (256 KB flash, 100-pin LQFP) The untested devices may be used as alternative to the tested ones but are excluded from support.
Chapter 5 Schematics
CHAPTER 6 Glossary
This chapter describes important terms used throughout this manual.
Adaptive clocking
A technique in which J-Link / J-Trace sends out a clock signal and waits for
the returned clock from the target device before generating the next clock
pulse. The technique allows the J-Link / J-Trace interface unit to adapt to
different signal drive capabilities, different cable lengths and variable
target clock speeds. Adaptive clocking can be used when it is supported by the
connected target device.
RESET
Abbreviation of System Reset. The electronic signal which causes the target
system other than the TAP controller to be reset. This signal is also known as
“nSRST” “nSYSRST”, “nRST”, or “nRESET” in some other manuals. See also nTRST.
nTRST
Abbreviation of TAP Reset. The electronic signal that causes the target system
TAP controller to be reset. This signal is known as nICERST in some other
manuals. See also nSRST.
RTCK
Returned TCK. The signal which allows Adaptive Clocking.
TCK
The electronic clock signal which times data on the TAP data lines TMS, TDI,
and TDO.
TDI
The electronic signal input to a TAP controller from the data source
(upstream). Usually, the TDI signal of J-Link is connected to the TDI of the
first TAP controller in a JTAG chain.
TDO
The electronic signal output from a TAP controller to the data sink
(downstream). Usually, the TDO signal of J-Link is connected to the TDO of the
last TAP controller in a JTAG chain.
TMS
The electronic signal Test Mode Select is an input to the TAP controller and
it is used to select different stages of state machine. It is clocked in into
the TAP controller using the TCK signal.(upstream). Usually, the TMS output
signal of J-Link is connected to the TMS input of the first TAP controller in
a JTAG chain. For Cortex-M CPUs this signal may also be used as the
bidirectional data signal SWDIO when the CPU is accessed in serial wire debug
mode SWD.
SWD
A serial communication protocol for Cortex M CPUs which may used for
communication with a debug device as an alternative communication channel to
JTAG. The SWD communication uses less pins.
SWDIO
The bidirectional electronic signal for communication of a Cortex M CPU
accessed in serial wire debug mode. Normally, the TMS input pin of the Cortex
M CPU is used as SWDIO pin in serial wire mode.
SWCLK
The electronic signal which times data on the SWDIO data line used in serial
wire debug mode. The SWCLK pin is typically the TCK pin used as JTAG clock
input, when JTAG is also supported by the device.
SWO
The electronic asynchronous signal for trace data output or SWV output data
which may be sent by the application on a Cortex-M CPU running in serial wire
debug mode. J-Link-OBRA4M2 is able to receive the data in asynchronous mode
when SWO of the target CPU is connected to the SWOin signal of J-Link-OB-
RA4M2. Normally the SWO output signal of a Cortex-M CPU is directed via the
TDO signal pin, but may be separated on some devices.
References
Read User Manual Online (PDF format)
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