SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The low-level programming sequence to set up the USB3_PHY subsystem for USB superspeed I/O operations is summarized in the Table 28-16
Step | Description | Comment |
---|---|---|
1. | Set the startup low performance OPP in the appropriate PRCM registers. | For more information regarding demanded OPP, see the device Data Manual. |
2. | Enable the PRCM.USB_OTG_SS_REF_CLK. | See Clock Domain Module Attributes, in Power, Reset, and Clock Management. |
3. | Enable the PRCM.L3INIT_L4_GICLK to enable the OCP2SCP1 interface adapter operation. | See Clock Domain Module Attributes, in Power, Reset, and Clock Management. |
4. | Software reset the OCP2SCP1 and poll until soft reset completion is indicated in status. | See Section 28.2.4.1. |
5. | Set up division ratio between the OCP clock (PRCM.L3INIT_L4_GICLK) and SCP clock to supply the serial configuration register domains of the DPLLCTRL_USB_OTG_SS . | See Section 28.2.4.1. |
6. | Set up necessary SYNC1 and SYNC2 timings to ensure no blocking of transactions over the SCP bus. | See Section 28.2.4.1. After this step, the user is ready to access the DPLLCTRL_USB_OTG_SS registers. |
7. | Configure DPLL_USB_OTG_SS to generate frequency (CLKDCOLDO) = 2.5 GHz. | See Section 28.2.4.3.7.3. |
8. | Software-assert the DPLLCTRL_USB_OTG_SS.PLL_GO[0] PLL_GO bit to 0x1 | Start the DPLL lock with desired parameters. |
9. | Poll the DPLLCTRL_USB_OTG_SS.PLL_STATUS[1] PLL_LOCK bit until it reads 1. | DPLL locked event |
10. | Perform a USB3_PHY tuning required for the Super-Speed OTG USB i/f operation | Follow steps described in Table 28-17, USB3_PHY Tuning Table. |
11. | Set USBOTGSS_GUSB3PIPECTL[31] PHYSOFTRST to 0x1 | Software reset the USB3_PHY over USB OTG SS controller PIPE port. Note that this reset does not impact settings made in step 10. |
12. | Software-trigger the USB3_PHY_TX power-up sequence. | For more details, see Section 28.2.4.2.3.1. |
13. | Software-trigger the USB3_PHY_RX power-up sequence. | For more details, see Section 28.2.4.2.3.1. |
14. | Clear USBOTGSS_GUSB3PIPECTL[31] PHYSOFTRST to 0x0 | Deassert the software reset bit after power-up sequence completion is indicated |
Physical address(2) [bits to modify] | Preferred value setting(1) |
---|---|
0x4A08 440C [31:27] | 0b10000 |
0x4A08 440C [17:14] | 0b1010 |
0x4A08 4428 [23:11] | 0b1110001100110 |
0x4A08 4428 [28:26] | 0b001 |
0x4A08 440C [6:5] | 0b00 |
0x4A08 441C [31:30] | 0b10 |
0x4A08 4424 [31:30] | 0b11 |
0x4A08 4438 [10:7] | 0b1001 |
0x4A08 4438 [2] | 0b0 |