If the auto-acknowledge feature is disabled (CSCR[AA] is 0) for an address thatgenerates an error, then the transfer can be terminated by asserting FB_TA. If theprocessor must manage a bus error differently, then asserting an interrupt to the corealong with FB_TA when the bus error occurs can invoke an interrupt handler.The device can hang if FlexBus is configured for external termination and the CSPMCRis not configured for FB_TA.31.5 Initialization/Application Information31.5.1 Initializing a chip-selectBefore using any other chip select to take it out of global chip select mode, you mustinitialize CS0.To initialize a chip-select:1. Write to the associated CSAR.2. Write to the associated CSCR.3. Write to the associated CSMR, including writing 1b to the Valid field (CSMRn[V]).31.5.2 Reconfiguring a chip-selectTo reconfigure a previously-used chip-select:1. Invalidate the chip-select by writing 0b to the associated CSMR's Valid field(CSMRn[V]).2. Write to the associated CSAR.3. Write to the associated CSCR.4. Write to the associated CSMR, including writing 1b to the Valid field (CSMRn[V]).Chapter 31 External Bus Interface (FlexBus)K22F Sub-Family Reference Manual, Rev. 4, 08/2016NXP Semiconductors 739
