Texas Instruments TMS320x2833 series User Manual

2.3.3.1 C Code Example to Unsecure
2.3.3.2 C Code Example to Resecure
www.ti.com Incorporating Code Security in User Applications
volatile int *CSM = (volatile int *)0x000AE0; //CSM register file
volatile int *PWL = (volatile int *)0x0033FFF8; //Password location
volatile int tmp;
int I;
// Read the 128-bits of the password locations (PWL)
// in flash at address 0x33 FFF8 - 0x33 FFFF
// If the device is secure, then the values read will
// not actually be loaded into the temp variable, so
// this is called a dummy read.
for (I=0; i < 8; I++) tmp = *PWL++;
// If the password locations (PWL) are all = ones (0xFFFF),
// then the device will now be unsecure. If the password
// is not all ones (0xFFFF), then the code below is required
// to unsecure the CSM.
// Write the 128-bit password to the KEY registers
// If this password matches that stored in the
// PWL then the CSM will become unsecure. If it does not
// match, then the device will remain secure.
// An example password of:
// 0x11112222333344445555666677778888 is used.
asm(" EALLOW"); // Key registers are EALLOW protected
*CSM++ = 0x1111; // Register KEY0 at 0xAE0
*CSM++ = 0x2222; // Register KEY1 at 0xAE1
*CSM++ = 0x3333; // Register KEY2 at 0xAE2
*CSM++ = 0x4444; // Register KEY3 at 0xAE3
*CSM++ = 0x5555; // Register KEY4 at 0xAE4
*CSM++ = 0x6666; // Register KEY5 at 0xAE5
*CSM++ = 0x7777; // Register KEY6 at 0xAE6
*CSM++ = 0x8888; // Register KEY7 at 0xAE7
asm(" EDIS");
volatile int *CSMSCR = 0x00AEF; //CSMSCR register
//Set FORCESEC bit
asm(" EALLOW"); //CSMSCR register is EALLOW protected.
*CSMSCR = 0x8000;
asm("EDIS");
SPRUFB0C – September 2007 – Revised May 2009 Code Security Module (CSM) 35
Submit Documentation Feedback

Texas Instruments TMS320x2833 series Specifications

General

Brand	Texas Instruments
Model	TMS320x2833 series
Category	Controller
Language	English