QSPI Class Reference

A QSPI Driver, used for communicating with QSPI slave devices. More...

#include <QSPI.h>

Inheritance diagram for QSPI:

Public Member Functions
	QSPI (PinName io0, PinName io1, PinName io2, PinName io3, PinName sclk, PinName ssel=NC, int mode=0)
	Create a QSPI master connected to the specified pins. More...
	QSPI (const qspi_pinmap_t &pinmap, int mode=0)
	Create a QSPI master connected to the specified pins. More...
qspi_status_t	configure_format (qspi_bus_width_t inst_width, qspi_bus_width_t address_width, qspi_address_size_t address_size, qspi_bus_width_t alt_width, qspi_alt_size_t alt_size, qspi_bus_width_t data_width, int dummy_cycles)
	Configure the data transmission format. More...
qspi_status_t	set_frequency (int hz=1000000)
	Set the qspi bus clock frequency. More...
qspi_status_t	read (int address, char *rx_buffer, size_t *rx_length)
	Read from QSPI peripheral with the preset read_instruction and alt_value. More...
qspi_status_t	write (int address, const char *tx_buffer, size_t *tx_length)
	Write to QSPI peripheral using custom write instruction. More...
qspi_status_t	read (qspi_inst_t instruction, int alt, int address, char *rx_buffer, size_t *rx_length)
	Read from QSPI peripheral using custom read instruction, alt values. More...
qspi_status_t	write (qspi_inst_t instruction, int alt, int address, const char *tx_buffer, size_t *tx_length)
	Write to QSPI peripheral using custom write instruction, alt values. More...
qspi_status_t	command_transfer (qspi_inst_t instruction, int address, const char *tx_buffer, size_t tx_length, const char *rx_buffer, size_t rx_length)
	Perform a transaction to write to an address(a control register) and get the status results. More...

Detailed Description

A QSPI Driver, used for communicating with QSPI slave devices.

The default format is set to Quad-SPI(1-1-1), and a clock frequency of 1MHz Most QSPI devices will also require Chip Select which is indicated by ssel.

Note

Synchronization level: Thread safe

Example:

// Write 4 byte array to a QSPI slave, and read the response, note that each device will have its specific read/write/alt values defined
 
#include "mbed.h"
 
#define CMD_WRITE 0x02
#define CMD_READ  0x03
#define ADDRESS   0x1000
 
// hardware ssel (where applicable)
QSPI qspi_device(QSPI_FLASH1_IO0, QSPI_FLASH1_IO1, QSPI_FLASH1_IO2, QSPI_FLASH1_IO3, QSPI_FLASH1_SCK, QSPI_FLASH1_CSN); // io0, io1, io2, io3, sclk, ssel
 
 
int main() {
    char tx_buf[] = { 0x11, 0x22, 0x33, 0x44 };
    char rx_buf[4];
    int buf_len = sizeof(tx_buf);
 
    qspi_status_t result = qspi_device.write(CMD_WRITE, 0, ADDRESS, tx_buf, &buf_len);
    if (result != QSPI_STATUS_OK) {
       printf("Write failed");
    }
    result = qspi_device.read(CMD_READ, 0, ADDRESS, rx_buf, &buf_len);
    if (result != QSPI_STATUS_OK) {
       printf("Read failed");
    }
 
}

Definition at line 86 of file QSPI.h.

Constructor & Destructor Documentation

QSPI() [1/2]

QSPI	(	PinName	io0,
		PinName	io1,
		PinName	io2,
		PinName	io3,
		PinName	sclk,
		PinName	ssel = NC,
		int	mode = 0
	)

Create a QSPI master connected to the specified pins.

io0-io3 is used to specify the Pins used for Quad SPI mode

Parameters

io0	1st IO pin used for sending/receiving data during data phase of a transaction
io1	2nd IO pin used for sending/receiving data during data phase of a transaction
io2	3rd IO pin used for sending/receiving data during data phase of a transaction
io3	4th IO pin used for sending/receiving data during data phase of a transaction
sclk	QSPI Clock pin
ssel	QSPI chip select pin
mode	Clock polarity and phase mode (0 - 3) of SPI (Default: Mode=0 uses CPOL=0, CPHA=0, Mode=1 uses CPOL=1, CPHA=1)

QSPI() [2/2]

QSPI	(	const qspi_pinmap_t &	pinmap,
		int	mode = 0
	)

Create a QSPI master connected to the specified pins.

io0-io3 is used to specify the Pins used for Quad SPI mode

Parameters

pinmap	reference to structure which holds static pinmap
mode	Clock polarity and phase mode (0 - 3) of SPI (Default: Mode=0 uses CPOL=0, CPHA=0, Mode=1 uses CPOL=1, CPHA=1)

Member Function Documentation

configure_format()

qspi_status_t configure_format	(	qspi_bus_width_t	inst_width,
		qspi_bus_width_t	address_width,
		qspi_address_size_t	address_size,
		qspi_bus_width_t	alt_width,
		qspi_alt_size_t	alt_size,
		qspi_bus_width_t	data_width,
		int	dummy_cycles
	)

Configure the data transmission format.

Parameters

inst_width	Bus width used by instruction phase(Valid values are QSPI_CFG_BUS_SINGLE, QSPI_CFG_BUS_DUAL, QSPI_CFG_BUS_QUAD)
address_width	Bus width used by address phase(Valid values are QSPI_CFG_BUS_SINGLE, QSPI_CFG_BUS_DUAL, QSPI_CFG_BUS_QUAD)
address_size	Size in bits used by address phase(Valid values are QSPI_CFG_ADDR_SIZE_8, QSPI_CFG_ADDR_SIZE_16, QSPI_CFG_ADDR_SIZE_24, QSPI_CFG_ADDR_SIZE_32)
alt_width	Bus width used by alt phase(Valid values are QSPI_CFG_BUS_SINGLE, QSPI_CFG_BUS_DUAL, QSPI_CFG_BUS_QUAD)
alt_size	Size in bits used by alt phase (must be a multiple of the number of bus lines indicated in alt_width)
data_width	Bus width used by data phase(Valid values are QSPI_CFG_BUS_SINGLE, QSPI_CFG_BUS_DUAL, QSPI_CFG_BUS_QUAD)
dummy_cycles	Number of dummy clock cycles to be used after alt phase

set_frequency()

qspi_status_t set_frequency

(

int

hz = 1000000

)

Set the qspi bus clock frequency.

Parameters

hz	SCLK frequency in hz (default = 1MHz)

Returns

Returns QSPI_STATUS_SUCCESS on successful, fails if the interface is already init-ed

read() [1/2]

qspi_status_t read	(	int	address,
		char *	rx_buffer,
		size_t *	rx_length
	)

Read from QSPI peripheral with the preset read_instruction and alt_value.

Parameters

address	Address to be accessed in QSPI peripheral
rx_buffer	Buffer for data to be read from the peripheral
rx_length	Pointer to a variable containing the length of rx_buffer, and on return this variable will be updated with the actual number of bytes read

Returns

Returns QSPI_STATUS_SUCCESS on successful reads and QSPI_STATUS_ERROR on failed reads.

write() [1/2]

qspi_status_t write	(	int	address,
		const char *	tx_buffer,
		size_t *	tx_length
	)

Write to QSPI peripheral using custom write instruction.

Parameters

address	Address to be accessed in QSPI peripheral
tx_buffer	Buffer containing data to be sent to peripheral
tx_length	Pointer to a variable containing the length of data to be transmitted, and on return this variable will be updated with the actual number of bytes written

Returns

Returns QSPI_STATUS_SUCCESS on successful reads and QSPI_STATUS_ERROR on failed reads.

read() [2/2]

qspi_status_t read	(	qspi_inst_t	instruction,
		int	alt,
		int	address,
		char *	rx_buffer,
		size_t *	rx_length
	)

Read from QSPI peripheral using custom read instruction, alt values.

Parameters

instruction	Instruction value to be used in instruction phase. Use QSPI_NO_INST to skip the instruction phase
alt	Alt value to be used in Alternate-byte phase. Use -1 for ignoring Alternate-byte phase
address	Address to be accessed in QSPI peripheral
rx_buffer	Buffer for data to be read from the peripheral
rx_length	Pointer to a variable containing the length of rx_buffer, and on return this variable will be updated with the actual number of bytes read

Returns

Returns QSPI_STATUS_SUCCESS on successful reads and QSPI_STATUS_ERROR on failed reads.

write() [2/2]

qspi_status_t write	(	qspi_inst_t	instruction,
		int	alt,
		int	address,
		const char *	tx_buffer,
		size_t *	tx_length
	)

Write to QSPI peripheral using custom write instruction, alt values.

Parameters

instruction	Instruction value to be used in instruction phase. Use QSPI_NO_INST to skip the instruction phase
alt	Alt value to be used in Alternate-byte phase. Use -1 for ignoring Alternate-byte phase
address	Address to be accessed in QSPI peripheral
tx_buffer	Buffer containing data to be sent to peripheral
tx_length	Pointer to a variable containing the length of data to be transmitted, and on return this variable will be updated with the actual number of bytes written

Returns

Returns QSPI_STATUS_SUCCESS on successful reads and QSPI_STATUS_ERROR on failed reads.

command_transfer()

qspi_status_t command_transfer	(	qspi_inst_t	instruction,
		int	address,
		const char *	tx_buffer,
		size_t	tx_length,
		const char *	rx_buffer,
		size_t	rx_length
	)

Perform a transaction to write to an address(a control register) and get the status results.

Parameters

instruction	Instruction value to be used in instruction phase. Use QSPI_NO_INST to skip the instruction phase
address	Some instruction might require address. Use -1 if no address
tx_buffer	Buffer containing data to be sent to peripheral
tx_length	Pointer to a variable containing the length of data to be transmitted, and on return this variable will be updated with the actual number of bytes written
rx_buffer	Buffer for data to be read from the peripheral
rx_length	Pointer to a variable containing the length of rx_buffer, and on return this variable will be updated with the actual number of bytes read

Returns

Returns QSPI_STATUS_SUCCESS on successful reads and QSPI_STATUS_ERROR on failed reads.