二手房装修注意什么:J-Link、J-Trace、Open JTAG区别
来源:百度文库 编辑:中财网 时间:2024/04/28 20:52:42
(2)另一种做法,就是做一个板,用此板直接接收来自keil,ads,iar等软件的调试命令,由此板做rdi->jtag协议的转换。然后与目标板通信,这就是jlink的工作原理。(这也就实现了USB转JTAG协议。)
有一回贴说:“大佬,两者都是软件完成的,只不过软件放的地方不一样(一个放计算机,一个放仿真器里面了).真正的硬件,就象是JTRACE一样,用FPGA来实现.实质上,还是软件到硬件的过程.”。
二、J-Link、J-Trace区别 最近在看《J-Link/J-Trace User Gudide(UM08001)》Page12,发现文中说JLink与JTrace区别,浅显易懂,摘录如下:
J-LinkJTAG emulator for ARM coresUSB driven JTAG interface for ARM cores.
J-TraceJTAG emulator for ARM coresUSB driven JTAG interface for ARM cores withTrace memory. supporting the ARM ETM (Embed-ded Trace Macrocell).
ARM Keil Tools官网(http://www.keil.com/pr/article/1141.htm)就更详细了,摘抄如下:The SEGGER J-Link is a USB to JTAG adapter supporting ARM7?, ARM9? and Cortex?-M3 processor based devices with JTAG speeds of up to 12MHz. It interfaces to all evaluation boards and target hardware using a standard 20-pin or 14-pin (optional) JTAG connector.
The SEGGER J-Trace is a combined unit offering real-time trace and JTAG debugging for all ARM7 and ARM9 devices with an integrated ETM (Embedded Trace Macrocell). An integrated 2MB trace buffer enables high speed instruction and data trace at speeds of up to 200MHz, connecting to the target device via a 38-pin Mictor cable. J-Trace also includes a J-Link interface for standard JTAG target debugging via a 20-pin connector.
Trace information from J-Trace is displayed in dedicated windows, providing a seamless interface with other μVision debug and analysis tools.
J-Link is part of several starter kits from various vendors and is indentical with SAM-ICE (from Atmel) and mIDAS-Link (from Analog Devices). With direct J-Link support users can now easily begin taking advantage of the unique and advanced features of RealView MDK compared to other tool offerings and starter kits.
RealView MDK is available from Keil or your local Keil distributor. J-Link and J-Trace are available from SEGGER Microcontroller and its world wide sales channels.
在贴子《jLINK和J-Trace仿真器的区别能否重复讲述一下?》中,精辟回答了J-Link和J-Trace的区别,如下: J-Link就像照相机,程序(在断点处)停下来才能看调试信息,通过JTAG/SWD接口;J-Trace就像录像机,可以纪录、回放整个调试接口,通过ETM接口。 最近一些Cortex-M3的芯片支持SWO接口,就好像是高速连拍照相机,采样间隔小的话,有那么点Trace的样子,这个调试功能在J-Link v7和EWARM v5.30中已经得到支持。
三、J-Link与Open JTAG区别 正如上文所述,这两者都是用来调试程序的,都实现了USB转JTAG协议功能,即用USB连接主机,用JTAG线连接板子的JTAG口,而这之间的转换通过J-Link或者Open JTAG转换。另,J-Link一般是独立的组件,而Open JTAG一般集成到板子上。更多比较可以参考资料[2][3],但[3]中说J-Link不支持Linux,现在可以了,我正在用,可以参考我的博文《Ubuntu 10.04下J-Link配置及使用》,目前功能还不是很完善,只是Beta版。
四、J-Link GDBServer与Open OCD openOCD(http://openocd.berlios.de/web/)是上位机程序(人可以直接发出操控命令的计算机,一般是PC。对应于下位机)。jlink gdbserver和openocd是一回事,都是担任一个 gdb server的角色,用来解释来自arm-elf-gdb的调试信号,并且控制硬件(Jlink或者openjtag)[4]。
参考资料:[1] 博文《OpenJTAG——Jlink的强劲对手》[2] 博文《看到好多玩过ARM的人还搞不懂hjtag与jlink的区别…》[3] 博文《OpenJTAG与Jlink/J-link的区别》 [4] 帖子《JLink-GDBServer + eclipse 的调试环境》