Hello,
We are currently in development using the TMS570LC4357 component.
By parsing the Datasheet "SPNS195C", we are finding in §6.5.4.1 "Signal Compare Operating Modese" , the "dedicated key" and "key register" terms.
Could you provide us the meaning of these terms and more information about these ones ?
Best regards,
Christopher.
Hello Christopher,
Safety-critical applications require run-time detection of faults in critical components in the device such as CPU and VIM. For this purpose, the CPU Compare Module for Cortex-R5F (CCM-R5F) compares the core bus outputs of two Cortex-R5F CPUs running in a lockstep configuration. This MCU also implements two VIM modules in lockstep configuration. Any difference in the core compare bus outputs of the CPUs or the VIMs is flagged as an error. For diagnostic purposes, the CCM-R5F also incorporates a self-test capability to allow for boot time checking of hardware faults within the CCM-R5F itself.
CPU / VIM Output Compare Diagnostic can run in one of the following four operating modes:
1. Active compare lockstep mode
2. Self-test
3. Error forcing
4. Self-test error forcing
The operating mode can be selected by writing a dedicated key to the key register (MKEY1, MKEY2) of the corresponding diagnostic.
MKEY1 is used to select the operating mode for the CPU Output Compare Diagnostic:
MKEY2 is used to select the operating mode for VIM Output Compare Diagnostic:
Please refer to chapter 13 of TRM (spnu563) for the details.
