- Forums
- Product Forums
- General Purpose MicrocontrollersGeneral Purpose Microcontrollers
- i.MX Forumsi.MX Forums
- QorIQ Processing PlatformsQorIQ Processing Platforms
- Identification and SecurityIdentification and Security
- Power ManagementPower Management
- Wireless ConnectivityWireless Connectivity
- RFID / NFCRFID / NFC
- Advanced AnalogAdvanced Analog
- MCX Microcontrollers
- S32G
- S32K
- S32V
- MPC5xxx
- Other NXP Products
- S12 / MagniV Microcontrollers
- Powertrain and Electrification Analog Drivers
- Sensors
- Vybrid Processors
- Digital Signal Controllers
- 8-bit Microcontrollers
- ColdFire/68K Microcontrollers and Processors
- PowerQUICC Processors
- OSBDM and TBDML
- S32M
- S32Z/E
-
- Solution Forums
- Software Forums
- MCUXpresso Software and ToolsMCUXpresso Software and Tools
- CodeWarriorCodeWarrior
- MQX Software SolutionsMQX Software Solutions
- Model-Based Design Toolbox (MBDT)Model-Based Design Toolbox (MBDT)
- FreeMASTER
- eIQ Machine Learning Software
- Embedded Software and Tools Clinic
- S32 SDK
- S32 Design Studio
- GUI Guider
- Zephyr Project
- Voice Technology
- Application Software Packs
- Secure Provisioning SDK (SPSDK)
- Processor Expert Software
- Generative AI & LLMs
-
- Topics
- Mobile Robotics - Drones and RoversMobile Robotics - Drones and Rovers
- NXP Training ContentNXP Training Content
- University ProgramsUniversity Programs
- Rapid IoT
- NXP Designs
- SafeAssure-Community
- OSS Security & Maintenance
- Using Our Community
-
- Cloud Lab Forums
-
- Knowledge Bases
- ARM Microcontrollers
- i.MX Processors
- Identification and Security
- Model-Based Design Toolbox (MBDT)
- QorIQ Processing Platforms
- S32 Automotive Processing Platform
- Wireless Connectivity
- CodeWarrior
- MCUXpresso Suite of Software and Tools
- MQX Software Solutions
- RFID / NFC
- Advanced Analog
-
- NXP Tech Blogs
- Home
- :
- 通用微控制器
- :
- Kinetis微控制器
- :
- NMI pin floating
NMI pin floating
I'm using K64 on a custom board. Unfortunately, The NMI pin was left floating (in its default state it was connected to a pull down resistor, but this caused the board to not be flashed at all so I left it floating).
I wanted to know the hazards, if any to this situation.
As I've understood there's an internal pull up and also the Flash Configuration Field is at its default state, so both these should cover the situation. Also, the board seems to be working fine.
Am I out of the woods?
已解决！ 转到解答。
Roy
A '0' on the NMI line with cause the chip to boot to EzPort mode and thus not work via JTAG.
The internal pull-up "should" keep it at '1' when it boots and avoid this issue and then also avoid any NMI firing once it starts.
If you are worried that the internal pull-up may not be strong enough to always ensure this you can also disable EzPort mode and the NMI pin in the flash configuration so that it can't ever become an issue after initial programming.
Regards
Mark
Roy
A '0' on the NMI line with cause the chip to boot to EzPort mode and thus not work via JTAG.
The internal pull-up "should" keep it at '1' when it boots and avoid this issue and then also avoid any NMI firing once it starts.
If you are worried that the internal pull-up may not be strong enough to always ensure this you can also disable EzPort mode and the NMI pin in the flash configuration so that it can't ever become an issue after initial programming.
Regards
Mark
