Code Security Module (CSM)
153
SPRUHE8E – October 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
System Control and Interrupts
1.10.3.3.2 C Code Example to Resecure C28x Zone1
volatile int *CSMSCR = 0x00AEF; //CSMSCR register
//Set FORCESEC bit
*CSMSCR = 0x8000;
shows different conditions for a zone to be secure or non-secure.
Table 1-33. Zone Security Status
CSM-ARMED
CSM-ALLZERO
CSM-ALLONE
CSM-MATCH
ZONE STATUS
0
X
X
X
SECURE
1
0
0
0
SECURE
1
1
0
X
SECURE
1
0
1
X
NON-SECURE
1
0
0
1
NON-SECURE
1.10.3.4 Environments That Require ECSL Unlocking
The following are the typical situations under which unsecuring memories can be required: the user
develops some main IP, and then outsources peripheral functions to a subcontractor who must be able to
run the customer code during debug but source code should not be visible to the subcontractor.
1.10.3.5 ECSL Password Match Flow
Password match flow (PMF) is essentially a sequence of eight dummy reads from password locations
(PWL) followed by eight writes to KEY registers.
shows how the PMF helps to initialize the
security logic registers and disable security logic.