PXS20RM Datasheet, PDF (1263/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

Self-Test Control Unit (STCU)
• The signature registers of each of the LBIST results match their corresponding expected values:
For each LBIST:
— Read the STCU_LBMISREL/H and STCU_LBIST_NMISRRL/H registers to check the
coherency with the STCU_LBS and STCU_LBE bits.
— Read the registers described in Section 42.1.3.1, Reported errors, and verify that their values
are as expected.
42.2 STCU main features
The STCU features include the following:
• Performs a one-time self test after an STCU reset event
• Provides register interfaces for both software and hardware:
— Hardware: SSCM write-one-time register interface
— Software: IPS register interface
• Manages LBISTs
• Manages MBISTs (embedded memory blocks)
• Performs self-checking: The Self Checker monitors critical internal signals during the self test.
• Provides a rich set of status and error information:
— Timeout flags if the self test does not start or finish within a limited amount of time
— Status flags for individual LBIST and MBIST operations
— Flags for STCU internal errors
• Software can confirm the integrity of the LBIST status information by directly comparing the
expected and actual results the LBIST operations.
42.3 Block diagram and components
Figure 42-4 shows a block diagram of the STCU.
STCU
Reset Event
Integrity SW
FCCU
Check Results
Failures
MC_RGM
Done
Functional Reset
LBIST Partitions
SSCM
Read
Parameters
NVM
Detect Status
Load
Parameters
IPS Interface
Registers
STCU
Collector
Watchdog
Timers
LBIST
Engine
Run Tests
MBIST Partitions
MBIST
Engine
Run Tests
Figure 42-4. STCU block diagram
Freescale Semiconductor
PXS20 Microcontroller Reference Manual, Rev. 1
42-5