Did I brick my STM32F2?

[mzimmers]

Hi all -

I'm modifying some legacy code written for a WICED device that contains an STM32F2xx. The original programmer had a passage that reduces down to:

#define OB_RDP_Level_0   ((uint8_t)0xAA)
#define OB_RDP_Level_1   ((uint8_t)0x55)
 
FLASH_OB_Unlock();
FLASH_OB_RDPConfig( OB_RDP_Level_1 );
FLASH_OB_Launch();
FLASH_OB_Lock();
NVIC_SystemReset( );

I have no idea where he got the value "55" but the upshot is I can't reset my OBs. When I try, I get this output from the programmer software:

  15:15:33 : Option byte command : -ob  RDP=170 
  15:15:33 : PROGRAMMING OPTION BYTES AREA ...
  15:15:33 :   Bank          : 0x00
  15:15:33 :   Address       : 0x40023c14
  15:15:33 :   Size          : 12 Bytes
  15:15:52 : UPLOADING OPTION BYTES DATA ...
  15:15:52 :   Bank          : 0x00
  15:15:52 :   Address       : 0x40023c14
  15:15:52 :   Size          : 12 Bytes
  15:15:52 : Error: Uploading Option Bytes bank: 0 failed
  15:15:52 : Error: Reloading Option Bytes Data failed
  15:15:52 : Time elapsed during option Bytes configuration: 00:00:18.761
  15:15:52 : Error: Unable to get core ID
  15:15:52 : Error: Unable to get core ID
  15:15:52 : Warning: Connection to device 0x411 is lost
  15:15:52 : Disconnected from device.

So, my questions are:

1. does anyone know what a value of "55" will do in this situation? (I guess what I'm really asking is, is it possible that it got interpreted as "CC"?)
2. Any suggestions for un-bricking this? I've unplugged and disconnected everything a few times.

Thanks for any assistance...

[Piranha]

1) What exactly is not clear from the description in reference manual?

0xAA: Level 0, no protection

0xCC: Level 2, chip protection (debug and boot from RAM features disabled)

Others: Level 1, read protection of memories (debug features limited)

2) Probably try SWD interface with a "connect under reset".

[mzimmers]

Hi Pirahna - thanks for the reply. What's wasn't clear to me is whether a value of 55 might have been interpreted as a CC, which (from my understanding) is a one way trip. I guess the passage from the reference manual you cited suggests not.

These are the settings I've used...thanks.