I don't have much experience with usage of FMx MCUs, but I hope the following stuffs could help you more or less.
The Flash Programming Manual has sector organization info:
A code example:
Thanks for this info, I will go into it in detail. Looking at the sector structure, there are only 5 sectors and they are 8k and 32k in size (for the 88k chips). I cannot afford to "waste" 32k of flash at the end of the application for a few bytes of parameters.
Is there a way I can reserve the second 8k block at the beginning of the flash and get the application to fit around it? I am thinking along the lines of placing all initialization code in the first 8k flash sector and then start the application in the third block but need some guidance as to how to do this.
Any help will be appreciated. I have never changed the standard memory assignments of the compiler. I use PSoC Creator as IDE.
I tried the sector erase routine in the flash UART example and it still hang the MCU.
I had a look to the mainflash.c provided by PDL 2.1.0, and figured out, it only may work when using the IAR compiler.
PSoC Creator uses GCC.
Flash routines for FM0+ need to me executed within the RAM area, so the mainflash.c must be copied and linked to RAM area, what is done for IDE by the directive __ramfunc
1) goto c:\Users\<your login>\Documents\Cypress\PDL\2.1.0\drivers\flash\
2) make a backup copy of existing mainflash.c
3) Copy the attached mainflash.c here.
4) Clean and build your project
Note: There will one warning, what is okay:
M0121:ignoring changed section attributes for .data
Additionally I have attached my test project (S6E1A1_MFlash.cyprj.Archive02.zip)
Next, you might prefer to use on of the smaller FLASH sectors, what is in the 'middle' of the complete FLASH.
Honestly the GCC (at least what I found) is not such comfortable like e.g. IAR.
Here my 'solution', see again attached example:
The 'problem' is, that the 'EEPROM' must be located within the FLASH-ROM area, in other words, the FLASH-ROM area must be spilt, what the GCC linker does not like.
Do as follow: on .\s6e1a12_rom.ld
ROM (rx) : ORIGIN = 0x00000000, LENGTH = 16K
ROM1 (rx) : ORIGIN = 0x00006000, LENGTH = 64K
RAM (rwx) : ORIGIN = 0x20000000, LENGTH = 6K
As you can see, SA2 (0x4000-0x3FFF) is not mentioned, as we will address it by pointers, no code must be linked.
You can add this area as well, if you like to map parameters from your code initially.
The Problem is, that your code per default is mapped to ROM, but this area is just 16K. If your code gets bigger, than you have to name it as ROM1 (or whatever name you like) see my dummycode.c, using __attribute__((section(".sectionROM1")))
Within the linker skript, I have added
} > ROM1
The 'disadvantage', you must split your code manually if it gets > 16KB, and you have to add __attribute__((section(".sectionROM1"))) to those additonal modules.