Module imxrt_boot_gen::flexspi

FlexSPI configuration block definitions

The FlexSPI module includes

• instruction sequences
• instruction lookup table (LUT)
• the FlexSPI configuration block

The flexspi types are used throughout the serial_flash API, since the FlexSPI configuration block is at the start of every serial NOR / NAND configuration block.

Sequences and LUTs

A Sequence is a collection of up to eight FlexSPI instructions (Instr). The FlexSPI controller sequentially executes instructions to perform reads, writes and I/O with a connected FLASH device. The FlexSPI controller finds each sequence in a LookupTable.

Use a SequenceBuilder to create Sequences:

use imxrt_boot_gen::flexspi::{Instr, Sequence, SequenceBuilder, Pads, opcodes::sdr::*};

const SEQ_READ: Sequence = SequenceBuilder::new()
    .instr(Instr::new(CMD, Pads::One, FAST_READ_QUAD_IO))
    .instr(Instr::new(RADDR, Pads::Four, 0x18))
    .instr(Instr::new(DUMMY, Pads::Four, 0x06))
    .instr(Instr::new(READ, Pads::Four, 0x04))
    .build();

const SEQ_READ_STATUS: Sequence = SequenceBuilder::new()
    .instr(Instr::new(CMD, Pads::One, READ_STATUS_REGISTER_1))
    .instr(Instr::new(READ, Pads::One, 0x04))
    .build();

Then, assign each sequence to a Command in a LookupTable:

use imxrt_boot_gen::flexspi::{Command, LookupTable};

const LUT: LookupTable = LookupTable::new()
    .command(Command::Read, SEQ_READ)
    .command(Command::ReadStatus, SEQ_READ_STATUS);

FlexSPI Configuration Block

Once you've created your sequences and lookup table, use the lookup table to create a ConfigurationBlock. See the ConfigurationBlock documentation for more information.

Modules

opcodes

FlexSPI lookup table instruction opcodes

Structs

ConfigurationBlock	FlexSPI configuration block
DeviceModeSequence	Sequence parameter for device mode configuration
Instr	A FlexSPI instruction
LookupTable	A sequence lookup table, part of the general FlexSPI configuration block
Sequence	A collection of FlexSPI instructions
SequenceBuilder	A Sequence builder
WaitTimeConfigurationCommands	Wait time for all configuration commands

Enums

ColumnAddressWidth	columnAdressWidth
Command	The default sequence definition lookup indices
DeviceModeConfiguration	Describes both the deviceModeCfgEnable field, and the deviceModeArg field, which is only valid if the configuration is enabled.
FlashPadType	sFlashPad field
Pads	Number of pads to use to execute the instruction
ReadSampleClockSource	readSampleClkSrc of the general FCB
SerialClockFrequency	serialClkFreq
SerialFlashRegion	A FlexSPI serial flash region

Constants

JUMP_ON_CS	JUMP_ON_CS FlexSPI instruction
RECOMMENDED_CS_HOLD_TIME	The recommended csHoldTime, 0x03.
RECOMMENDED_CS_SETUP_TIME	The recommended csSetupTime, 0x03.
STOP	STOP FlexSPI instruction