SPNS254A June 2022 – March 2024 TMS570LC4357-SEP
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
Some applications may need to use both the FlexRay and the Ethernet interfaces.The FlexRay controller requires the VCLKA2 frequency to be 80 MHz, while the MII interface requires VCLKA4_DIVR_EMAC to be 25 MHz and the RMII requires VCLKA4_DIVR_EAMC to be 50 MHz.
These different frequencies are supported by adding special dedicated clock source selection options for the VCLKA4_DIVR_EMAC clock domain. This logic is shown in Figure 7-7.
The PLL2 post_ODCLK is brought out as a separate output from the PLL wrapper module. There are two additional dividers implemented at the device-level to divide this PLL2 post_ODCLK by 8 and by 16.
As shown in Figure 7-7, the VCLKA4_SRC configured through the system module VCLKACON1 control register is used to determine the clock source for the VCLKA4 and VCLKA4_DIVR. An additional multiplexor is implemented to select between the VCLKA4_DIVR and the two additional clock sources – PLL2 post_ODCLK/8 and post_ODCLK/16.
Table 7-17 lists the VCLKA4_DIVR_EMAC clock source selections.
VCLKA4_SRC FROM VCLKACON1[19–16] | CLOCK SOURCE FOR VCLKA4_DIVR_EMAC |
---|---|
0x0 | OSCIN / VCLKA4R |
0x1 | PLL1CLK / VCLKA4R |
0x2 | Reserved |
0x3 | EXTCLKIN1 / VCLKA4R |
0x4 | LF LPO / VCLKA4R |
0x5 | HF LPO / VCLKA4R |
0x6 | PLL2CLK / VCLKA4R |
0x7 | EXTCLKIN2 / VCLKA4R |
0x8–0xD | VCLK |
0xE | PLL2 post_ODCLK/8 |
0xF | PLL2 post_ODCLK/16 |