CPU Bus Compare
PD Inactivity
Monitor
VIM Bus Compare
Checker CPU
Inactivity Monitor
CPU1
(Main CPU)
CPU2
(Checker
CPU)
2 cycle delay
VIM1
VIM2
2 cycle delay
Inputs to CPU1
Inputs to CPU2
Lockstep mode
cpu2clk
cpu1clk
Outputs from CPU1 to
the system
Outputs CPU2 to the
system
Safe values (values
that will force the
Z
l Œ
Wh
[
• }µš‰µš•
to inactive states)
Lockstep
mode
CCM-R5F
Compare errors
ESM
PDx
PDy
Module Operation
499
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
CPU Compare Module for Cortex-R5F (CCM-R5F)
Figure 13-1. Block Diagram
13.2 Module Operation
As described in
, there are four different run-time diagnostics supported by the CCM-R5F.
The CCM-R5F compares the core bus outputs of the master and checker Cortex-R5F CPUs on the
microcontroller and signals an error on any mismatch. This comparison is started 6 CPU clock cycles after
the CPU comes out of reset to ensure that CPU output signals have propagated to a known value after
reset. Once comparison is started, the CCM module continues to monitor the outputs of the two CPUs
without any software intervention. If an error is detected by the CCM-R5F, a software handler is necessary
to implement the appropriate response to the error dependent on application needs. The module principles
of operation are applicable to both the CPU output compare as described above as well as to the VIM
output compare.