SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The DSP1 and DSP2 subsystems inputs a primary non-divided clock (DSP1_FICLK / DSP2_FICLK) and based on it (DSP_CLK1), internally generates either a divided by 2 clock (DSP_CLK2) version or a divided by 3 clock (DSP_CLK3). The divided clock determines the operation rate of the DSP subsystem logic and bus interfaces. The division is defined upon device boot time through signal level externally applied on the device sysboot15 input. The actual bit configuration is latched upon power-on reset in Control Module register CTRL_CORE_BOOTSTRAP[15] SYS_BOOT_15_CLOCK_DIVIDER boot status bit. For more details, refer to the Section 18.4.6.14.1, System Boot Status Settings of the chapter, Control Module.
Only DSP_CLK3 clock is supported on this SoC. Upon boot time, sysboot15 set at '1' selects a DSP_CLK3 divided clock version for the DSP subsystem logic and bus interfaces. For SR1.1, sysboot15 must be tied to vdd to select DSP_CLK3, but for SR2.0 it is configurable. For more information, see Permanent PU/PD disabling (SR 2.0 only) in Control Module.
The clock operating mode setting (DSP_CLK2 or DSP_CLK3) must be static just before and continually after reset deassertion. This signal will also drive the configuration to the DSP C66x CorePac for the XMC_MDMA_CLK, EMC_SDMA_CLK, and EMC_CFG_CLK configurations.
The DSPSS1 / DSPSS2 subsystem input clock frequency (DSP_CLK1) corresponds to the PRCM DSP1_GFCLK / DSP2_GFCLK frequency that is configured in the device PRCM registers.
For valid DSP_CLK1 (and hence for DSP_CLK3 = DSP_CLK1 / 3) frequency range, see the Operating Performance Points section of the device Data Manual.
The Section 5.3.2 also shows the distribution of the different DSP subsystems blocks within the two DSP local clock domains CD0_CLK (running on DSP_CLK frequency) and CD1_CLK (running on DSP_CLK2 or DSP_CLK3 frequency).