TMS320F28377D: Impossible to program OTP PSWDLOCK second time, from disabled to enabled

Hello Hareesh, 

thanks for you answer. According to question 2,  secured my device but the passwords are visible if I connect through JTAG (I can connect with "Wait boot mode" status and without introducing password in CSMPSWD of Flash Settings). So, with my secured device:

• I can connect through JTAG
• I can read passwords at adress 0x78028 --> this is what I don't want
• I can't read the rest of memory (all addresses show 0x0000) without introducing correct CSMPSWD in flash settings
• I can't load new .out without introducing correct CSMPSWD in flash settings

So my question was related to second item, I didn't want to be able to read passwords through JTAG without introducing the correct CSMPSWD.I thought I would be able to change PSWDLOCK at the end of my debug process in order to block this passwords, but I don't know if it is already possible or not.

Thank you

Etiam,

            I believe I understand the issue. I have a feeling you are stuck with the same issue as https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1271793/tms320f28379d-problem-with-programming-otp_pswdlock.

Etiam said:

• I can connect through JTAG
• I can read passwords at adress 0x78028 --> this is what I don't want

Understandable, since you have programmed the passwords but not enabled security yet, which is done by writing to the PSWDLOCK register.

Etiam said:

I can't read the rest of memory (all addresses show 0x0000) without introducing correct CSMPSWD in flash settings

Expected since the secure resources are not unsecured until the Password Match Flow (PMF) is executed

Etiam said:

I can't load new .out without introducing correct CSMPSWD in flash settings

This is expected as well. You cannot program the Flash until you have unsecured it.

Did you program the whole OTP in one attempt or did you try to program the security settings first and the PSWDLOCK later?

Hareesh,

the first time I programmed the device was with this dcsm.asm file , so I think I programmed all the security settings including PSWDLOCK (even it was 0xFFFFFFFF).

;----------------------------------------------------------------------
; Zone 1
;----------------------------------------------------------------------
     .sect "dcsm_otp_z1_linkpointer"
      .retain
      .long 0x1FFFFFFF
      .long 0xFFFFFFFF     ;Reserved
      .long 0x1FFFFFFF
      .long 0xFFFFFFFF     ;Reserved
      .long 0x1FFFFFFF
      .long 0xFFFFFFFF     ;Reserved
    
     .sect "dcsm_otp_z1_pswdlock"
      .retain
      .long 0xFFFFFFFF
      .long 0xFFFFFFFF     ;Reserved
      
     .sect "dcsm_otp_z1_crclock"
      .retain
      .long 0xFFFFFFFF
      .long 0xFFFFFFFF     ;Reserved
   
;;     .sect "dcsm_otp_z1_bootctrl"
;;      .retain
;;      .long 0xFFFFFFFF     ;Reserved
;;      .long 0x49550B5A
      
     .sect "dcsm_zsel_z1"
      .retain
      .long 0x000000FF       ;Z1-EXEONLYRAM
      .long 0x00003FFF      ;Z1-EXEONLYSECT
      .long 0x10005555          ;Z1-GRABRAM
      .long 0x05555555         ;Z1-GRABSECT
      
      .long 0x--------  ; my custom passwords
      .long 0x--------
      .long 0x--------
      .long 0x--------

My dcsm.cmd file was:

MEMORY
{
PAGE 0 :  /* Program Memory */

   /* Z1 OTP.  LinkPointers */
   DCSM_OTP_Z1_LINKPOINTER   : origin = 0x78000, length = 0x00000C
   /* Z1 OTP.  GPREG1/GPREG2 */
   DCSM_OTP_Z1_GPREG         : origin = 0x7800C, length = 0x000004
   /* Z1 OTP.  PSWDLOCK/RESERVED */
   DCSM_OTP_Z1_PSWDLOCK	    : origin = 0x78010, length = 0x000004
   /* Z1 OTP.  CRCLOCK/RESERVED */
   DCSM_OTP_Z1_CRCLOCK	    : origin = 0x78014, length = 0x000004
   /* Z1 OTP.  RESERVED/BOOTCTRL */
   DCSM_OTP_Z1_BOOTCTRL	    : origin = 0x7801C, length = 0x000004

   /* DCSM Z1 Zone Select Contents (!!Movable!!) */
   /* Z1 OTP.  Z1 password locations / Flash and RAM partitioning */
   DCSM_ZSEL_Z1_P0	        : origin = 0x78020, length = 0x000010

   /* Z2 OTP.  LinkPointers */
   DCSM_OTP_Z2_LINKPOINTER	: origin = 0x78200, length = 0x00000C
   /* Z2 OTP.  GPREG1/GPREG2 */
   DCSM_OTP_Z2_GPREG	        : origin = 0x7820C, length = 0x000004
   /* Z2 OTP.  PSWDLOCK/RESERVED */
   DCSM_OTP_Z2_PSWDLOCK	    : origin = 0x78210, length = 0x000004
   /* Z2 OTP.  CRCLOCK/RESERVED */
   DCSM_OTP_Z2_CRCLOCK	    : origin = 0x78214, length = 0x000004
   /* Z2 OTP.  GPREG3/BOOTCTRL */
   DCSM_OTP_Z2_BOOTCTRL	    : origin = 0x7821C, length = 0x000004

   /* DCSM Z2 Zone Select Contents (!!Movable!!) */
   /* Z2 OTP.  Z2 password locations / Flash and RAM partitioning  */
   DCSM_ZSEL_Z2_P0	        : origin = 0x78220, length = 0x000010

}

SECTIONS
{
   dcsm_otp_z1_linkpointer 	: > DCSM_OTP_Z1_LINKPOINTER		PAGE = 0
   dcsm_otp_z1_pswdlock		: > DCSM_OTP_Z1_PSWDLOCK		PAGE = 0
   dcsm_otp_z1_crclock		: > DCSM_OTP_Z1_CRCLOCK			PAGE = 0
   dcsm_otp_z1_bootctrl		: > DCSM_OTP_Z1_BOOTCTRL		PAGE = 0, type = DSECT
   dcsm_zsel_z1				: > DCSM_ZSEL_Z1_P0				PAGE = 0

   dcsm_otp_z2_linkpointer	: > DCSM_OTP_Z2_LINKPOINTER		PAGE = 0, type = DSECT
   dcsm_otp_z2_pswdlock		: > DCSM_OTP_Z2_PSWDLOCK		PAGE = 0, type = DSECT
   dcsm_otp_z2_crclock		: > DCSM_OTP_Z2_CRCLOCK			PAGE = 0, type = DSECT
   dcsm_otp_z2_bootctrl		: > DCSM_OTP_Z2_BOOTCTRL		PAGE = 0, type = DSECT
   dcsm_zsel_z2				: > DCSM_ZSEL_Z2_P0				PAGE = 0, type = DSECT
}

I will read the post you mentioned, thank you.

Another last question, do I have to do this in dcsm.asm file prior to production?

; For code security operation,after development has completed, prior to
; production, all other zone select block locations should be programmed
; to 0x0000 for maximum security.
; If the first zone select block at offset 0x10 is used, the section
; "dcsm_rsvd_z1" can be used to program these locations to 0x0000.
; This code is commented out for development.

; .sect "dcsm_rsvd_z1"
; .loop (1e0h)
; .int 0x0000
; .endloop

I don't understand two things about this code:

1. Why the first zone select block is 0x10, I thought the first one was 0x20. 

2. If i'm using another zone select block, do I have to change de value of  .loop(1e0h), right?

Thank you very much

Etiam,

   Please give me a day or two to analyze this.

Hi Etiam,

Have you tried all of the following before attempting to program the .out file that has PSWDLOCK enabled?

• Unlock the zone via the On-Chip flash tool before programming new .out file that has PSWDLOCK enabled.
• Power-cycle the device before programming .out file
• Make sure both CPUs have been reset and are not running before programming new .out file

Thank you,

Luke