6 Replies Latest reply on Apr 6, 2016 1:37 PM by userc_39811

Allocation of "NVRAM" in on-board flash

userc_39811 Aug 18, 2017 1:21 PM

I am attempting to allocate the last row of on-board flash (start address: 0x0001FF80) to store non-volatile data (data that survives re-boot). Unfortunately, the bootloader over-writes ALL of on-board flash (0x00000000 - 0x0001FFFF). when loading the application!

Is there an easy way to instruct the bootloader NOT to overwrite the last row of on-board flash?

David Perkins

Cratus Technology

1. Re: Allocation of "NVRAM" in on-board flash

JoMe_264151 Apr 6, 2016 12:24 PM (in response to userc_39811)

Welcome in the forum, David!

The area of flash you used is already in use by the bootloader. See the memory map in Bootloader datasheet page 13. You may declare your area just below the metadata and exclude it from checksum generation.



Bob
Like Show 0 Likes(0)

Actions
2. Re: Allocation of "NVRAM" in on-board flash

userc_39811 Apr 6, 2016 12:33 PM (in response to JoMe_264151)

Thanks, Bob.

Could you direct me where to set these values?
Like Show 0 Likes(0)

Actions
3. Re: Allocation of "NVRAM" in on-board flash

userc_39811 Apr 6, 2016 12:54 PM (in response to JoMe_264151)

I search for 'metadata' in entire workspace. Only shows up in files in 'Generated_Source' folder. I assume these regions are declared in the GUI. The only variables I see are 'heap size' and 'stack size' under the 'System' tab in 'Firmware.cydwr'
Like Show 0 Likes(0)

Actions
4. Re: Allocation of "NVRAM" in on-board flash

JoMe_264151 Apr 6, 2016 1:17 PM (in response to userc_39811)

Wrong place to search. Look into Bootloader datasheet and search for "metadata".

Bob
Like Show 0 Likes(0)

Actions
5. Re: Allocation of "NVRAM" in on-board flash

userc_39811 Apr 6, 2016 1:24 PM (in response to userc_39811)

Still no help. Where do I find out EXACTLY where metadata is located in my application?
Like Show 0 Likes(0)

Actions
6. Re: Allocation of "NVRAM" in on-board flash

userc_39811 Apr 6, 2016 1:37 PM (in response to userc_39811)

I'm using row 1022 - the row just below metadata (assuming metadata takes up one 128-byte row).
Like Show 0 Likes(0)

Actions

Go to original post