If you see datasheet, section 2 Block diagram, you may see which S32K3 derivatives are configured with lockstep and which are configured for decoupled mode (diagram shows dual core or triple core). Easiest and safest way is to order proper variant.
Otherwise you can change configuration by program new DCF client (OTP memory, attached embedded excel S32K3xx_DCF_clients.xlsx) with LOCKSTEP_EN = 0, it makes checker core as independent or otherwise. Programming of DCF records is not trivial task but it is manageable. User would be aware that he can easily destroy the chip in case the programming is not done properly and the device may never exit from reset.
- Register description regarding lockstep
It is spread over whole reference manual. Due to lockstep/decoupled there are changes in internal memory organization, XBAR ports, FCCU faults and so. These all changes are related to the fact that lockstepped cores act as one (from SW point of view) )and decoupled as two cores.
- Does lockstep have interrupts or pin-outputs ? (Description of Lockstep usage and features)
There is one FCCU fault related to lockstep error, it also may invoke interrupt or error output pin indication.
- How to configure Lockstep outputs (hardware pins or errors) ?
Pay attention to RM, section 50.6.5 EOUT interface
