ST STM32L4+ Series Reference Manual page 555

RM0432
19 Octo-SPI interface (OCTOSPI)
19.1 Introduction
The OCTOSPI supports two frame formats used by most external serial memories such as
serial PSRAMs, serial NAND and serial NOR Flash memories, HyperRAM™ and
HyperFlash™ memories:
•
Indirect mode: all the operations are performed using the OCTOSPI registers.
•
Status polling-mode: the external memory status register is periodically read and an
interrupt can be generated in case of flag setting.
• Memory-mapped mode: the external memory is memory mapped and it is seen by the
system as if it was an internal memory supporting both read and write operations.
The OCTOSPI supports two frame formats:
•
the classical frame format with the command, address, alternate byte, dummy cycles
and data phase
•
the HyperBus™ frame format
19.2 OCTOSPI main features
• Three functional modes: Indirect, Status polling, and Memory-mapped
•
Read and write support in Memory-mapped mode
• Supports for single, dual, quad and octal communication
•
Dual-quad mode, where 8 bits can be sent/received simultaneously by accessing two
quad memories in parallel
•
SDR (single-data rate) and DTR (double-transfer rate) support
•
Data strobe support
•
Fully programmable opcode
•
Fully programmable frame format
•
HyperBus support
•
Integrated FIFO for reception and transmission
• 8, 16, and 32-bit data accesses allowed
•
DMA channel for indirect mode operations
• Interrupt generation on FIFO threshold, timeout, operation complete, and access error.
RM0432 Rev 6
Octo-SPI interface (OCTOSPI)
555/2301
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