ST STM32L4+ Series Reference Manual page 610

OCTOSPI I/O manager (OCTOSPIM)
Bits 3:2 Reserved, must be kept at reset value.
Bit 1 CLKSRC: CLK/CLKn Source for Port n
Bit 0 CLKEN: CLK/CLKn Enable for Port n
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This bit selects the source of Port n CLK/CLKn.
0: OCTOSPI1_CLK/CLKn in non muxed mode / MUXED_CLK/CLKn in muxed mode
1: OCTOSPI2_CLK/CLKn in non muxed mode / unused port in muxed mode
This bit enables the Port n CLK/CLKn.
0: CLK/CLKn for Port n is disabled
1: CLK/CLKn for Port n is enabled
RM0432 Rev 6
RM0432