SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The ISS has three asynchronous clock domains. Most of the logic uses ISS_MAIN_FLCK; the other clock domains are used for interfaces.
Table 9-4 provides a high-level view of clocks. The frequencies provided are the values for OPP_HIGH. For more information on supported OPPs and corresponding maximum clock frequencies, refer to device-specific Data Manual.
Name | Description |
---|---|
PCLK | CAL_B has video port output having its own pixel clock. This pixel clock is generated from the functional clock (ISS_MAIN_FCLK) and then provided to the ISP via multiplexing. Up to 532 MHz for OPP_HIGH. |
ISS_MAIN_FLCK | Functional clock. It is used by all ISS submodules and ISS top-level resources. Up to 532 MHz for OPP_HIGH. |
To save power, the ISS clocks can be divided at PRCM level. The PCLK must always be less or equal to the ISS_MAIN_FLCK. The internal configuration clock (CFGCLK, used for the internal ISS configuration network) is always half the ISS_MAIN_FLCK.
The functional clock of some submodules can be cut by software to reduce power consumption by cutting off or turning on the modules from the ISS_CLKCTRL register. Also, the pixel clocks sent by submodules to ISP can be cut off from the corresponding ISS_CLKCTRL bit-fields.