If Chip Protection is enabled, does Debug Select make any difference?

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
JoBr_1593366
Level 5
Level 5
100 sign-ins 50 questions asked 100 replies posted

In PSoC 4200L, when Chip Protection is in Protected or Kill mode, then debugging is disabled, correct? 

So is there then any difference whether Debug Select is set to GPIO vs SWD, which also disables debugging?

Also when working with a bootloader, the Flash Protection does nothing but prevent the BL from overwriting itself, correct?  So if it says "Flash used: 33190 of 65536 bytes (50.6%). Bootloader: 9728 bytes." then just protect the first 9728/256  = 38 rows?

0 Likes
1 Solution
Rakshith
Moderator
Moderator
Moderator
250 likes received 1000 replies posted 750 replies posted

Hi JoBr_1593366​,

Debug Select set to GPIO is used to repurpose the SWD pins. You will still be able to acquire the device.

Chip protection is used to block access to the device. When the Chip Protection is set to Protected, you will not be able to access the device until you do a complete erase. You cannot read from the device as well.

When the Chip Protection is set to Kill mode, any access to the device is blocked and even the flash erase will not work. You can refer to the Architecture TRM for information regarding this.

Also when working with a bootloader, the Flash Protection does nothing but prevent the BL from overwriting itself, correct?

Yes, that is correct. It is used to prevent the bootloader code from being modified in any way. It includes protection from any malicious code or the user application accidentally writing to the bootloader region.
You can refer to this KBA for write protecting bootloader code - Bootloader Host Error: “The Flash Row is not Valid for the Selected Array” - KBA221445

Thanks and Regards,

Rakshith M B

Thanks and Regards,
Rakshith M B

View solution in original post

1 Reply
Rakshith
Moderator
Moderator
Moderator
250 likes received 1000 replies posted 750 replies posted

Hi JoBr_1593366​,

Debug Select set to GPIO is used to repurpose the SWD pins. You will still be able to acquire the device.

Chip protection is used to block access to the device. When the Chip Protection is set to Protected, you will not be able to access the device until you do a complete erase. You cannot read from the device as well.

When the Chip Protection is set to Kill mode, any access to the device is blocked and even the flash erase will not work. You can refer to the Architecture TRM for information regarding this.

Also when working with a bootloader, the Flash Protection does nothing but prevent the BL from overwriting itself, correct?

Yes, that is correct. It is used to prevent the bootloader code from being modified in any way. It includes protection from any malicious code or the user application accidentally writing to the bootloader region.
You can refer to this KBA for write protecting bootloader code - Bootloader Host Error: “The Flash Row is not Valid for the Selected Array” - KBA221445

Thanks and Regards,

Rakshith M B

Thanks and Regards,
Rakshith M B