Symptoms Some users cannot access MCU peripherals normally by add peripheral initialization code to MCUXpresso SDK TrusZone demo. For example, when add Flash operation code in the security world, the program code jumps to HardFault_Handler after running to function FLASH_INIT(), and the execution of Flash erase and Flash program operations fails also, as follows: Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Diagnosis As shown in figure 2 and figure 3, when the program code runs to code return VERSION_FLASH_API_TREE->flash_init(config), it automatically jumps to HardFault_Handler. VERSION_FLASH_API_TREE is located in the 0x1301fe00 address of the boot rom, the flash erase api is located in address 0x1300413bU, and the flash program api is located in address 0x1300419dU (the corresponding program code is shown in figure 6). All above addresses are not security privilege. Figure 6        From the 7.5.3.1.2 TrustZone preset data chapter in user manual, after enabling the TrustZone configuration, users must configure the security level of the entire ROM address space to security priority (S-Priv) in order to ensure that the ROM area can be accessed normally by the security area code. Figure 7 Solution Below is the steps of how to resolve this issue. The demo is based on MCUXpresso SDK demo hello_world_s. Step 1: firstly we use the TEE tool integrated with MCUXpresso IDE to configure the security level of the Boot ROM address area, as shown in Figure 8, double-click the Boot-ROM area in the Memory attribution map window, and configure the sector’s security level in the corresponding Security access configuration window on the left. Figure 8 Step 2: Second, when operating Flash or other peripherals in the security area, users must configure the security level of correlative peripherals to the security priority(S-Priv).        When operating flash in the SDK TrustZone demo, the MCU uses two slave peripherals, so users must configure their security level to S-Priv. Figure 9 Please Note: From the usermanual, when operating flash, the system clock frequency cannot exceed 100MHZ. When using the function of FLASH_Program(), because the s_buffer is 512-byte aligned, the BUFFER_LEN is equal to 512/N.   The above configuration of the security level can be configured through the TEE tool integrated the MCUXpresso IDE. After completing configuration, click Update Code to automatically update the relevant code in the tzm_config.c file, as shown in Figure 10. Figure 10 The updated code is shown in Figure 11 below. It is obvious that the security level settings of boot rom memory and peripheral (FLASH, SYSCTRL) have changed. If you do not use the TEE tool, you can also manually modify tzm_config.c to configure the same security options. Figure 11 Third-party tools users: Because many users are accustomed to using third-party development tools such as Keil or IAR, but these IDEs do not integrate the TEE tool, users need to check the configuration requirements of related registers in user manual when modifying the security level of related areas and peripherals in TrusZone, and update the associated code in the tzm_config.c file (similar to Figure 11) to complete the related configuration. In addition, NXP released the MCUXpresso Config Tools, which integrates MCU-related configuration functions. Users can download and install this tool to perform configurations and update codes. The download link is as follows: https://www.nxp.com/design/software/development-software/mcuxpresso-software-and tools/mcuxpresso-config-tools-pins-clocks-peripherals:MCUXpresso-Config-Tools   Introduction of MCUXpresso Config Tools After the tool is installed, open the configuration tool, select Create a new configuration based on an SDK example or hello world project, click Next, as shown in Figure 12: Figure 12   In Start Development window, follow below steps to generate project. As shown in Figure 13. Figure 13 After the tzm_config.c file is updated, copy or import it to the corresponding folder of KEIL or IAR third-party development tools, and it can be used normally.          

LPC55xx系列的MCUXpresso SDK使用FLASH API来实现FLASH驱动。 一些用户在执行如下FLASH写操作时可能会遇到如下的问题： status = FLASH_Program(&flashInstance, destAdrss, (uint8_t *)s_bufferFF, 8);       执行完上述代码后，对应的地址区间数据没有变化，写入失败，返回错误代码101，如下图所示, 错误代码101看上去有点陌生，这在之前的LPC产品中并不常见，我们在用户手册中搜索FLASH driver status code，可以查找到错误代码101为FLASH 对齐操作错误（Alignment Error）。   对齐操作错误是什么？我们先来看程序是如何对FLASH_Program函数进行定义的。 FLASH写函数定义如下： status_t FLASH_Program(flash_config_t *config, uint32_t start, uint32_t *src, uint32_t lengthInBytes); 新用户经常会忽略掉用户手册中对于这个API的介绍“the required start and the lengthInBytes must be page size aligned”，这句话的意思是在执行FLASH_Program函数时，写入的起始地址和数据长度必须512字节对齐，所以如果我们把代码 status = FLASH_Program(&flashInstance, destAdrss, (uint8_t *)s_bufferFF, 8); 更正为 status = FLASH_Program(&flashInstance, destAdrss, (uint8_t *)s_bufferFF, 512); FLASH_Program函数就可以运行成功。   请注意：在2.6.x版本的SDK中，FLASH_Program函数的注释将参数的起始地址和数据长度错误的表述为字对齐，2.7.0版本的SDK已经对注释进行了修正。即使你想要操作一个字节，lengthInBytes也是512字节对齐。   最后：建议用户在遇到关于FLASH API操作失败的相关问题，一定要查看用户手册中的FLASH驱动状态码，我们可以从UM11126中的第九章节FLASH API部分找到它，如下图所示。  

Contents     Introduction to OPAMP. ........................................1     Usage of LPC5536-OPAMP. ................................2 2.1 Follower OPAMP. .................................................2 2.2 Non-inverting OPAMP. .........................................3 2.3 Differential OPAMP. ..............................................3     Test Preparation of LPC5536-EVK. ......................4     Test Result ............................................................5 4.1      Follower Test ....................................................6 4.2      Non-inverting Test ............................................7 4.2.1 Error Analysis. ...................................................7 4.2.2 Gain Error and Output Offset Error ...................8 4.2.3 OPAMP Output Error .........................................9 4.4 Differential Test ...................................................10     Conclusion. .........................................................11   The Article shows the OPAMP performance test that the precision of LPC5536-OPAMP matches the description in the product data sheet. The gain error is less than 5%, and the input offset voltage is less than 5mV, which can meet the presicion need to a certain extent. It is worth mentioning that the output error of LPC5536-OPAMP is very small at low magnification. For example, the full-range error is just single-digit mV at the magnifications of 2X and 5X in non-inverting mode. For scenarios requiring higher precision, users can connect the external high-precision resistors to achieve higher output precision.  The article includes detailed test steps and EVK board settings. For detail, see attached article.  

Because the LPC55S69 has PowerQuad, in SDK example code, the FFT/FIR/IIR and the other DSP function are implemented by the Powerquad module instead of the Cortex-CM33 core.  This is the Powerquad example to implement the DSP function:'   But if customers want to use CMSIS-DSP to implement the DSP function based on Cortex-CM33 instead of Powerquad module, customers can not import SDK example, he has to create a new project, this is the procedures: 1)Create a new project by clicking New->Create a new C/C++ Project   2)select the processor like LPC55S69 3)In the following menu,click CMSIS Driver, and check the CMSIS_DSP_Library and CMSIS_DSP_Library_Source You have to click the Driver which can select your peripherals driver you will use.    3)as the following screenshot, after completion, you can see the CMSIS-DSP source code and library have included in the project