SPRUJF8 May 2026 TMS320F28P551SG
To achieve a higher level of security on secure Flash sectors and RAM blocks that store critical user code (instruction opcodes), the Execute-Only protection feature is provided. When the Execute-Only protection is turned on for any secure Flash sector or RAM block, data reads to that Flash sector or RAM block are disallowed from any code (even from secure code allocated to the same zone). Execute-only protection for a Flash sector and RAM block can be turned on by configuring the bit field associated for that particular Flash sector or RAM block in the zone's ZxOTP_EXEONLYSECTx and ZxOTP_EXEONLYRAMx register, respectively. Note that the zone must also have ownership of that sector/RAM block as designated by ZxOTP_GRABSECTx and ZxOTP_GRABRAMx.
Users may need to copy the code from secure Flash to secure RAM for better performance. The Secure Copy Code function in the Secure ROM can be leveraged to allow EXEONLY Flash to be copied to EXEONLY RAM in a secure manner. Please refer to Section 5.6 for more details.