DSPIC33 EP128GM310中的擦除问题

在DSPIC33 EP128GM310中，我有一个Bootloader驻留在内存的最顶端（0x15400到0x155EC）。这个特殊的PIC有一个单一的通用段代码保护（GCP）的整个内存。为了进行自闪烁，一般段写保护（GWRP）必须设置为1（不写保护）。因此，我使用的是GWRP=1。当PIC未被锁定（GCP=1）时，我可以擦除/写入/验证内存（0x00000到0x153FF）的每一页（512条指令）。但是，如果PIC被锁定（GCP＝0），我不能擦除或写入第一页（0x000 000～0x00 3FF）。当PIC被锁定时，所有其他页（0x00400-0x153FF）擦除/写入/验证正确。第一页当然是复位向量和中断向量指针。当固件更新发生时，我需要改变所有这些指针…因此，它们指向正确的地址。只有一个擦除函数（通过NVMCON设置为NVMOP＝0011）。我尝试了所有可能的NVMOP位组合，以防文档遗漏了第一页“特殊”这一事实。是否有人遇到了无法擦除/写入第一页的问题？



      以下为原文

    I have a bootloader that resides in the very top of memory (0x15400 to 0x155EC) in a dsPIC33EP128GM310.  This particular PIC has a single general segment code-protect (GCP) for the entire memory.  In order to do self flashing, the general segment write-protect (GWRP) must be set to 1 (not write protected).  So, I am using GWRP=1.

I can erase/write/verify every single page (512 instructions) of memory (0x00000 to 0x153FF) when the PIC is not locked (GCP=1).  However, I can not erase or write the first page (0x00000-0x003FF) if the PIC is locked (GCP=0).  All other pages (0x00400-0x153FF) erase/write/verify correctly when the PIC is locked.

The first page is of course the reset vector and interrupt vector pointers.  I need to change all of these pointers when a firmware update occurs... so they point to the correct address.

There is only one erase function (set via the NVMCON with NVMOP=0011).  I tried every possible combination of NVMOP bits just in case the documentation was missing the fact that the first page was "special".  Has anyone run into this problem of not being able to erase/write just the first page?