ST STM32L4+ Series Reference Manual page 974

DSI Host (DSIHOST) applied to STM32L4R9xx and STM32L4S9xx only
30.14 Programing procedure
To operate DSI Host, you must be familiar with the MIPI
programmable register is accessible through the APB interface.
30.14.1 Programing procedure overview
The programming procedure for Video mode or Adapted Command mode must respect the
following order:
1. Configure the RCC (refer to the RCC chapter)
–
–
2. Optionally configure the GPIO (if tearing effect requires GPIO usage for example)
3. Optionally valid the ISR
4. Configure the LTDC (refer to the LTDC chapter)
–
–
5. Turn on the DSI regulator and wait for the regulator ready as described in
Section 30.12.5
6. Configure the DSI PLL, turn it ON and wait for its lock as described in
7. Configure the D-PHY parameters in the DSI Host and the DSI Wrapper to define D-
PHY configuration & timing as detailed in
8. Configure the DSI Host timings as detailed in
9. Configure the DSI Host Flow Control and DBI interface as detailed in
10. Configure the DSI Host LTDC interface as detailed in
11. Configure the DSI Host for Video mode as detailed in
Command mode as detailed in
12. Enable the D-PHY setting the DEN bit of the DSI_PCTLR
13. Enable the D-PHY clock lane setting the CKEN bit of the DSI_PCTLR
14. Enable the DSI Host setting the EN bit of the DSI_CR
15. Enable the DSI Wrapper setting the DSIEN bit of the DSI_WCR
16. Optionally send DCS commands through the APB generic interface to configure the
display
17. Enable the LTDC in the LTDC
18. Start the LTDC flow through the DSI Wrapper (CR.LTDCEN = 1)
In Video mode, the data streaming starts as soon as the LTDC is enabled.
In Adapted Command mode, the frame buffer update is launched as soon as the
CR.LTDCEN bit is set.
30.14.2 Configuring the D-PHY parameters
The D-PHY requires a specific configuration prior starting any communications. The
configuration parameters are stored either in the DSI Host or the DSI Wrapper.
974/2301
Enable clock for DSI and LTDC
Configure LTDC PLL, turn it ON and wait for its lock
Program the panel timings
Enable the relevant layers
Section 30.14.2
Section 30.14.3
Section 30.14.7
RM0432 Rev 6
®
DSI specification. Every software
Section 30.12.4
Section 30.14.4
Section 30.14.5
Section 30.14.6 or Adapted
RM0432