Configure STC_ENA Key to
enable SelfTest
Program the STCGCR0 registers to
specify the number of intervals(
N
), timeout
counter etc for a selftest run.
StartUp selftest?
Configure CPU in WFI mode
(IDLE mode)
WFI executed?
CPU SelfTest execution.
CPU configured into safe mode
SelfTest Done?
Read the SelfTest and system status
registers.
Retrieve state of CPU and Registers
NO
NO
NO
YES
YES
YES
CPU reset asserted
and continue Application Software.
Store CPU state and Registers in Memory
before starting STC Test
Configure STCCLK rate using STCCLKDIV
register in SYS2 register frame.
Application Self-Test Flow
346
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
CPU Self-Test Controller (STC) Module
8.2.4 Self-Test Completion and Error Generation
At the end of each interval, the 128 bit MISR value (reflected in registers CPUx_CURMISR[3:0]) from the
DBIST controller is shifted into the STC. This is compared with the golden MISR value stored in the ROM.
At the end of a CPU self-test, the STC controller updates the status flags in the Global Status Register
(STCGSTAT) and resets the CPU. In case of a MISR mismatch or a test timeout, an error is generated
through the ESM module. TEST_ERR signal is asserted when an MISR miss-compare occurs during the
self-test. A TO_ERR is asserted when a timeout occurs during the self-test, meaning the test could not
complete within the time specified in the timeout counter preload register STCTPR. However, at the
device level, these two errors are combined and mapped to a single ESM channel. To identify which error
occurred, user software must check the global status register (STCGSTAT) and fail status register
STCFSTAT in the ESM interrupt service routine.
illustrates the application self-test test flow chart, drawn based on the assumption that the
device has gone through startup, necessary clocks initialized and SYSESR register bits cleared.
Figure 8-2. Application Self-Test Flow Chart