Table 131. Lcd Behavior In Low-Power Modes; Table 132. Lcd Interrupt Requests - ST STM32L4x6 Reference Manual

RM0351
22.4 LCD low-power modes
the LCD controller can be displayed in Stop mode or can be fully disabled to reduce power
consumption.
Sleep
Low-power run
Low-power sleep
Stop 0
Stop 1
Stop 2
Standby
Shutdown
22.5 LCD interrupts
The table below gives the list of LCD interrupt requests.
Interrupt event
Start Of Frame (SOF)
Update Display Done (UDD)
Start of frame (SOF)
The LCD start of frame interrupt is executed if the SOFIE (start of frame interrupt enable) bit
is set (see
writing the SOFC bit to 1 in the LCD_CLR register when executing the corresponding
interrupt handling vector.
Update display done (UDD)
The LCD update display interrupt is executed if the UDDIE (update display done interrupt
enable) bit is set (see
cleared by writing the UDDC bit to 1 in the LCD_CLR register when executing the
corresponding interrupt handling vector.
Depending on the product implementation, all these interrupts events can either share the
same interrupt vector (LCD global interrupt), or be grouped into 2 interrupt vectors (LCD
SOF interrupt and LCD UDD interrupt). Refer to the
details.
In order to enable the LCD interrupts, the following sequence is required:

Table 131. LCD behavior in low-power modes

Mode
No effect. LCD interrupt causes the device to exit the Sleep mode.
No effect.
No effect. LCD interrupt causes the device to exit the Low-power sleep
mode.
No effect. LCD interrupt causes the device to exit the Stop mode.
The LCD peripheral is powered down and must be reinitialized after exiting
Standby or Shutdown mode.

Table 132. LCD interrupt requests

Event flag
SOF
UDD
Section 22.6.2: LCD frame control register
Section 22.6.2: LCD frame control register
DocID024597 Rev 3
Liquid crystal display controller (LCD)
Description
Event flag/Interrupt
clearing method
Write SOFC =1
Write UDDC = 1
(LCD_FCR)). SOF is cleared by
Table 42: STM32L4x6 vector table
Interrupt enable
control bit
SOFIE
UDDIE
(LCD_FCR)). UDD is
for
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