Figure 3-31 shows the power-on reset sequence of the IPU2 subsystem.
The assumptions on power-on reset assertion are:
- The IPU subsystem is held in reset by the PRCM module and the following are asserted:
- IPU2_PWRON_RST
- IPU2_RET_RST
- IPU2_CPU0_RST
- IPU2_CPU1_RST
- IPU2_RST
The power-on reset sequence is:
- Software clears the RM_IPU2_RSTCTRL[2] RST_IPU bit in the PRCM module register to release the IPU shared cache and CACHE_MMU_IPU from reset.
- The PRCM module releases IPU2_PWRON_RST once the reset manager counter (PRM_RSTTIME[14:10] RSTTIME2) reaches its limit and the IPU2_GFCLK is running. Upon deassertion of the POR signal, the IPU subsystem starts the CPU and CACHE_MMU_IPU initialization sequence.
- When the reset sequence of Step 2 completes and the reset manager counter (PRM_RSTTIME[14:10] RSTTIME2) expires, the PRCM module releases the IPU_MMU_CACHE_RST and IPU2_RET_RST signals.
- MPU software must configure CACHE_MMU_IPU once CACHE_MMU_IPU is out of reset. After CACHE_MMU_IPU configuration and cache initialization is done, MPU software clears the RM_IPU2_RSTCTRL[0] RST_CPU0 bit in the PRCM module register.
- The PRCM module releases IPU2_CPU0_RST, which causes IPU_C0 to start booting.
- MPU software can clear the RM_IPU2_RSTCTRL[1] RST_CPU1 bit in the PRCM module register so that the PRCM module releases the IPU2_CPU1_RST to IPU_C1.