APSR (APSR register STL module)

General Description

The APSR (Application Program Status Register) test detects stuck-at faults in the APSR bits that are implemented and writable on the core: the condition flags N, Z, C, and V, and, where the core has them, the sticky saturation flag Q and the greater-than-or-equal flags GE[3:0].

More Information

The test performs the following major tasks:

 1) Saves the APSR value.
 2) Writes a known pattern to the writable APSR bits, checks the N, Z, C, and V
    flags with conditional branches, reads APSR back, masks the result to the
    implemented bits, and compares it with the pattern.
 3) Repeats step 2 with the complementary pattern, so that every tested bit is
    checked at 0 and at 1.
 4) Restores the saved APSR value, and checks the restored value.

The tested bits depend on the core, and are selected at compile time:

Core	Tested bits
Armv6-M and Armv8-M Baseline (Cortex-M0+, M23)	N, Z, C, V
Armv7-M (Cortex-M3)	N, Z, C, V, Q
Cores with the DSP extension (Cortex-M4, M7, M33)	N, Z, C, V, Q, GE

API Reference
	Functions