Jlinkcmd它可以方便用户在非仿真的情况下，hold内核、单步、全速、设置断点、查看内核和外设寄存器、读取flash代码等等，方便大家拥有最高的权限查看在运行中的MCU情况，查找非IDE仿真情况下，MCU运行异常的原因。
目录
驱动安装
打开Jlinkcmd
建立连接
常用指令
实测举例
指令大全
驱动安装
Jlink相关文档及软件资料见如下官网网址：
SEGGER - The Embedded Experts - Downloads - J-Link / J-Trace
Jlink驱动下载可选如下官网网址：
SEGGER - The Embedded Experts - Downloads
打开Jlinkcmd
我们可以在开始菜单打开Jlinkcmd；
也可以在安装目录中打开Jlinkcmd；
还可以在KEIL软件中debug窗口中打开；
建立连接
1.输入connect建立连接；
2.输入芯片型号，直接回车可以选择默认选项；
3.根据实际情况选择JTAG或者SWD；
4.设置下载速度，直接回车可以选择默认选项；
正确的连接目标芯片后：
识别到内核，并通知“已识别”。
常用指令
Mem 读内存
mem8 读8字节内存
mem16 读16字节内存
mem32 读32字节内存
w1 写8字节内存
w2 写16字节内存
w4 写32字节内存
h 停止cpu运行的程序
setbp 设置断点
g 跳到代码段地址执行
s 单步执行（调试用）
r 复位
q 退出
实测举例
由以上指令运行结果可简单看出，PC初始值为0x080001E0，运行结束后指向0x08001764；
由以上指令运行结果可简单看出，地址0x00000004存储的值为：0x080001E1，地址0x08000004存储的值为：0x080001E1
指令大全
| Command (long) | Command (short) | Explanation |
| Basic | ||
| ? | ? | Show information about all or specific commands |
| Exit | Exit | Close J-Link connection and quit |
| ExitOnError | EoE | Exit on error |
| Sleep | Sleep | Waits the given time (in milliseconds) |
| Log | Log | Enables log to file |
| ExpDevList | ExpDevList | Export device names from DLL internal device list to text file |
| ExpDevListXML | ExpDevListXML | Export device names from DLL internal device list to XML file |
| Configuration - J-Link | ||
| USB | USB | Connect to J-Link via USB |
| IP | IP | Connect to J-Link via TCP/IP or to Remote Server |
| SelectProbe | SelPrb | Show list of all connected probes via specified interface. The Probe to communicate with can then be selected |
| ShowEmuList | ShowEmuList | Show list of all connected probes via specified interface |
| Power | Power | Switch power supply for target (5V-Supply pin) on or off |
| VTREF | VTREF | Set fixed value for VTref on J-Link |
| VCOM | VCOM | Enable/disable VCOM Takes effect after power cycle of the probe |
| Reboot | Reboot | Reboots the connected probe. |
| ShowFWInfo | F | Show firmware info |
| ShowHWStatus | St | Show hardware status |
| License | License | Show list of all available license commands |
| IPAddr | IPAddr | Show/Assign IP address and subnetmask of/to connected Probe |
| GWAddr | GWAddr | Show/Assign network gateway address of/to connected Probe |
| DNSAddr | DNSAddr | Show/Assign network DNS server address of/to connected Probe |
| ShowConf | Conf | Show configuration of the connected Probe |
| Calibrate | Calib | Calibrate the target current measurement |
| Configuration - Target (CPU) | ||
| Connect | Con | Connect to target device |
| Device | Device | Select specific device J-Link shall connect to |
| SelectInterface | SI | Select target interface |
| Speed | Speed | Set target interface speed |
| LE | LE | Change mode to little endian |
| BE | BE | Change mode to big endian |
| Debugging | ||
| Halt | H | Halt CPU |
| IsHalted | IH | Return current CPU state |
| WaitHalt | WH | Wait until CPU is halted or timeout is reached |
| Go | G | Start CPU if halted |
| Reset | R | Reset CPU |
| ResetX | RX | Reset CPU with delay after reset |
| RSetType | Rst | Set the current reset type |
| Step | S | Execute step(s) on the CPU |
| IS | IS | Identify length of scan chain select register |
| MS | MS | Measure length of scan chain |
| Regs | Regs | Display CPU register contents |
| RReg | RReg | Read register |
| WReg | WReg | Write register |
| MoE | MoE | Shows mode-of-entry (CPU halt reason) |
| SetBP | SetBP | Set breakpoint |
| ClearBP | ClrBP | Clear breakpoint |
| SetWP | SetWP | Set watchpoint |
| ClearWP | ClrWP | Clear watchpoint |
| VCatch | VC | Write vector catch |
| SetPC | SetPC | Set the PC to specified value |
| ReadAP | ReadAP | Read CoreSight AP register |
| WriteAP | WriteAP | Write CoreSight AP register |
| ReadDP | ReadDP | Read CoreSight DP register |
| WriteDP | WriteDP | Write CoreSight DP register |
| RCP15Ex | RCE | Read CP15 register |
| WCP15Ex | WCE | Write CP15 register |
| Term | Term | Visualize printf output using DCC (SEGGER DCC handler running on target) |
| Debugging - Memory operation | ||
| Mem | Mem | Read memory and show corresponding ASCII values |
| Mem8 | Mem8 | Read 8-bit items |
| Mem16 | Mem16 | Read 16-bit items |
| Mem32 | Mem32 | Read 32-bit items |
| Write1 | W1 | Write 8-bit items |
| Write2 | W2 | Write 16-bit items |
| Write4 | W4 | Write 32-bit items |
| Debugging - JTAG related | ||
| JTAGConf | JTAGConf | Set number of IR/DR bits before Target device |
| JTAGId | I | Read JTAG Id |
| WJTAGIR | WJIR | Write JTAG command (IR) |
| WJTAGDR | WJDR | Write JTAG data (DR) |
| WJTAGRaw | WJR | Write Raw JTAG data |
| ResetTAP | RTAP | Reset TAP Controller using state machine (111110) |
| ResetTRST | RT | Reset TAP Controller using nTRST |
| Debugging - ICE | ||
| ICE | ICE | Show state of the embedded ICE macrocell (ICE breaker) |
| ReadICE | RI | Read Ice register |
| WriteICE | WI | Write Ice register |
| TRACE | ||
| TClear | TC | Clear TRACE buffer |
| TSetSize | TSS | Set TRACE size of trace buffer |
| TSetFormat | TSF | Set TRACE Format |
| TShowRegions | TSR | Show TRACE Regions (and analyze trace buffer) |
| TStart | TStart | Start TRACE |
| TStop | TStop | Stop TRACE |
| SWO | ||
| SWOSpeed | SWOSpeed | Show supported SWO speeds |
| SWOStart | SWOStart | Start SWO |
| SWOStop | SWOStop | Stop SWO |
| SWOStat | SWOStat | Display SWO status |
| SWORead | SWORead | Read and display SWO data |
| SWOShow | SWOShow | Read and analyze SWO data |
| SWOFlush | SWOFlush | Flush SWO data |
| SWOView | SWOView | View SWO terminal data |
| Flash programming | ||
| Erase | Erase | Erase flash (range) of selected device |
| LoadFile | LoadFile | Load data file into target memory |
| SaveBin | SaveBin | Save target memory range into binary file |
| VerifyBin | VerifyBin | Verfy if specified bin file is at the specified target memory location |
| Flasher File I/O Commands | ||
| FWrite | FWr | (Flasher only) Write file to probe |
| FRead | FRd | (Flasher only) Read file from probe |
| FShow | FShow | (Flasher only) Read and display file from probe |
| FDelete | FDel | (Flasher only) Delete file on probe |
| FSize | FSz | (Flasher only) Display size of file on probe |
| FList | FList | (Flasher only) List directory on probe |
| SecureArea | SecureArea | (Flasher only) Creates/Removes secure area on probe |
| Measurement and test commands | ||
| PowerTrace | PowerTrace | Perform power trace (not supported by all models) |
| TestWSpeed | TestW | Measure download speed into target memory |
| TestRSpeed | TestR | Measure upload speed from target memory |
| TestCSpeed | TestC | Measure CPU speed |
| TestNWSpeed | TestNW | Measure network download speed |
| TestNRSpeed | TestNR | Measure network upload speed |
| MR | MR | Measure RTCK react time |
| J-Link Pin control | ||
| Clock | C | Output clock(s) on the TCK pin |
| Clock00 | C00 | Output clock(s) on the TCK pin, with TDI == 0 and TMS == 0 |
| ClrTCK | TCK0 | Clear TCK pin |
| SetTCK | TCK1 | Set TCK pin |
| ClrTDI | TDI0 | Clear TDI pin |
| SetTDI | TDI1 | Set TDI pin |
| ClrTMS | TMS0 | Clear TMS pin |
| SetTMS | TMS1 | Set TMS pin |
| ClrTRST | TRST0 | Clear TRST pin |
| SetTRST | TRST1 | Set TRST pin |
| ClrRESET | R0 | Clear RESET pin |
| SetRESET | R1 | Set RESET pin |
