如题，从官网EVT压缩包中的IAP例程只有跳转到boot的isp下载，不是IAP区的自定义烧录，另外也有看过ch559的IAP例程，是通过跳转至IAP区然后上位机烧录，但个人能力有限，移植至554上使用难度不小，希望大大可以给一份可以在554上用的IAP例程以及上位机例程。

论坛搜了一圈发现有CH552的IAP例程，我去试试移植，有问题再求助大大们！

The problem is the bootloader in the CH554 devices. For loader version >= 2.31 the IAP call does not exist anymore. I just found that call in V1.1. 

Actuall devices of CH554 (CH552) are delivered with V2.5.

For CH559 its a bit different: In V2.31 there is still the IAP call suported. I dont know if there are newer versions of the bootloader for CH559 exit. I know of V2.0 and V2.31.

I guess IAP will not work with new versions of the bootloader because of security reasons. Bootloaders with IAP support all have included the keil libfunction _ICALL. More infos on my Gid pages or (in German) here 

https://www.mikrocontroller.net/topic/462538?goto=new#6820478

@OJZ 可以参考下CH549的IAP例程设计，更接近CH554的代码风格，移植相对简单点

CH546iap20230627代码逻辑保护.zip

@usbman Chips are updated to the latest BOOT version before leaving the factory。

@TECH29 大大，这个例程我这边有一些不太明白的地方：

1、codeflash地址预留0x0000~0x0078是有什么具体作用，我看没有程序烧录到这个地址，ch554这部分是否也有作用?

2、IAP工程地址起始从0x6000开始，APP地址从0x104开始，那么烧录后上电是如何进入APP或者IAP区？我理解上电后复位后boot从0x0000开始执行。

3、IAP工程中，USB初始化中开启了中断，然后主函数中又通过while判断标志轮询中断函数，这是否有必要？

4、IAP工程中的flash擦除流程，从554头文件看没有擦除命令定义，这部分是否就不适用ch554了？

I describe what I have done in the past:

I created a simple USB device just with control EP no other EPs. for flashing I used a vendor request

wIndex= adrress wValue=16 bit flashcontend no datastage. I linked that code to 0x3000 with modified startup.a51 (keil). For crccheck i used a second request wIndex = usr code size wValue = expected CRC. 

If for any reason the crc fails I flash LMP 0x3000 + NOP at address 0x0000 so the IAP is reactivated again.

The same LMP 0x3000 + NOP is additionally linked a small asm module to the IAP code

     CSEG at 0

     LJMP 0x3000

    NOP

    end

This ensures that after Flashing the IAP code with WCHIspTool IAP starts automatically.

- CH552/554 dont need a erase. 

- IAP code can not use any interrupt 

- usercode can be at max from 0x0000 to 0x2FFF

@OJZ 
1，因为前面有四个字节的跳转信息是一定不能被擦除修改的，而flash是页编程，因此直接跳过前面一页

2,  0地址的跳转信息做到

3，因为IAP中不能出现中断，中断向量表留给APP用

4，554可以直接编程不需要擦