RZT Flexible Software Package Documentation  Release v2.2.0

 
Serial Communications Interface (SCI) SPI (r_sci_spi)

Functions

fsp_err_t R_SCI_SPI_Open (spi_ctrl_t *p_ctrl, spi_cfg_t const *const p_cfg)
 
fsp_err_t R_SCI_SPI_Read (spi_ctrl_t *const p_ctrl, void *p_dest, uint32_t const length, spi_bit_width_t const bit_width)
 
fsp_err_t R_SCI_SPI_Write (spi_ctrl_t *const p_ctrl, void const *p_src, uint32_t const length, spi_bit_width_t const bit_width)
 
fsp_err_t R_SCI_SPI_WriteRead (spi_ctrl_t *const p_ctrl, void const *p_src, void *p_dest, uint32_t const length, spi_bit_width_t const bit_width)
 
fsp_err_t R_SCI_SPI_Close (spi_ctrl_t *const p_ctrl)
 
fsp_err_t R_SCI_SPI_CalculateBitrate (uint32_t bitrate, sci_spi_clock_source_t clock_source, sci_spi_div_setting_t *sclk_div)
 
fsp_err_t R_SCI_SPI_CallbackSet (spi_ctrl_t *const p_ctrl, void(*p_callback)(spi_callback_args_t *), void const *const p_context, spi_callback_args_t *const p_callback_memory)
 

Detailed Description

Driver for the SCI peripheral on RZ microprocessor. This module implements the SPI Interface.

Overview

Features

Configuration

Build Time Configurations for r_sci_spi

The following build time configurations are defined in fsp_cfg/r_sci_spi_cfg.h:

ConfigurationOptionsDefaultDescription
Parameter Checking
  • Default (BSP)
  • Enabled
  • Disabled
Default (BSP) If selected code for parameter checking is included in the build.
DMAC Support
  • Enabled
  • Disabled
Enabled If support for transferring data using the DMAC will be compiled in. Even if DMAC support is enabled, DMAC is not used without adding DMAC driver.
Multiplex Interrupt
  • Enabled
  • Disabled
Disabled Enable multiplex interrupt for a single driver.

Configurations for Connectivity > SPI (r_sci_spi)

This module can be added to the Stacks tab via New Stack > Connectivity > SPI (r_sci_spi).

ConfigurationOptionsDefaultDescription
NameName must be a valid C symbolg_spi0 Module name.
ChannelValue must be a non-negative integer0 Select the SCI channel. Do not select the safety channel when using DMAC.
Operating Mode
  • Master
  • Slave
Master Select the SPI operating mode.
Clock Phase
  • Data sampling on odd edge, data variation on even edge
  • Data sampling on even edge, data variation on odd edge
Data sampling on odd edge, data variation on even edge Select the clock edge to sample data.
Clock Polarity
  • Low when idle
  • High when idle
Low when idle Select clock level when idle.
Bit Order
  • MSB First
  • LSB First
MSB First Select the data bit order.
Clock Source
  • SCInASYNCCLK
  • PCLKM
SCInASYNCCLK Select whether the SCInASYNCCLK or peripheral clock (PCLKM) is used for generating the SCK frequency.
CallbackName must be a valid C symbolsci_spi_callback A user callback function that is called from the sci spi interrupts when a transfer is completed or an error has occurred.
Receive Interrupt PriorityMCU Specific OptionsSelect the receive interrupt priority.
Transmit Interrupt PriorityMCU Specific OptionsSelect the transmit interrupt priority.
Transmit End Interrupt PriorityMCU Specific OptionsSelect the transmit end interrupt priority.
Error Interrupt PriorityMCU Specific OptionsSelect the error interrupt priority.
BitrateValue must be an integer greater than 08000000 Enter the desired bitrate.

If the requested bitrate cannot be achieved, the settings with the largest possible value that is less than or equal to the requested bitrate is used. The theoretical bitrate is printed in a comment in the generated sci_spi_extended_cfg_t structure.

Clock Configuration

The SCI_SPI clock is derived from PCLKSCIn.

Pin Configuration

This module uses SCIn_MOSI, SCIn_MISO, SCIn_SPCK, and SCIn_SS pins to communicate with on board devices.

Note
At high bit rates, it might be necessary to configure the pins with IOPORT_CFG_DRIVE_HIGH.

Usage Notes

Transfer Complete Event

The transfer complete event is triggered when all of the data has been transfered. In slave mode if the SS pin is de-asserted then no transfer complete event is generated until the SS pin is asserted and the remaining data is transferred.

Performance

At high bit rates, interrupts may not be able to service transfers fast enough. In master mode this means there will be a delay between each data frame. In slave mode this could result in RX Overflow errors.

In order to improve performance at high bit rates, it is recommended that the instance be configured to service transfers using the DMAC.

Transmit From RXI Interrupt

After every byte, the SCI SPI peripheral generates a transmit buffer empty interrupt and a receive buffer full interrupt. Whenever possible, the SCI_SPI module handles both interrupts in the receive buffer full interrupt. This improves performance when the DMAC is not being used.

Slave Select Pin

Limitations

Examples

Basic Example

This is a basic example of minimal use of the SCI_SPI in an application.

static volatile bool g_transfer_complete = false;
void r_sci_spi_callback (spi_callback_args_t * p_args)
{
{
g_transfer_complete = true;
}
}
void sci_spi_basic_example (void)
{
uint8_t tx_buffer[TRANSFER_SIZE];
uint8_t rx_buffer[TRANSFER_SIZE];
/* Configure Slave Select Line 1 */
R_BSP_PinSet(R_BSP_IoRegionGet(SLAVE_SELECT_LINE_1), SLAVE_SELECT_LINE_1);
/* Configure Slave Select Line 2 */
R_BSP_PinSet(R_BSP_IoRegionGet(SLAVE_SELECT_LINE_2), SLAVE_SELECT_LINE_2);
fsp_err_t err = FSP_SUCCESS;
/* Initialize the SPI module. */
err = R_SCI_SPI_Open(&g_spi_ctrl, &g_spi_cfg);
/* Handle any errors. This function should be defined by the user. */
handle_error(err);
/* Assert Slave Select Line 1 */
R_BSP_PinClear(R_BSP_IoRegionGet(SLAVE_SELECT_LINE_1), SLAVE_SELECT_LINE_1);
/* Start a write/read transfer */
g_transfer_complete = false;
err = R_SCI_SPI_WriteRead(&g_spi_ctrl, tx_buffer, rx_buffer, TRANSFER_SIZE, SPI_BIT_WIDTH_8_BITS);
handle_error(err);
/* Wait for SPI_EVENT_TRANSFER_COMPLETE callback event. */
while (false == g_transfer_complete)
{
;
}
/* De-assert Slave Select Line 1 */
R_BSP_PinSet(R_BSP_IoRegionGet(SLAVE_SELECT_LINE_1), SLAVE_SELECT_LINE_1);
/* Wait for minimum time required between transfers. */
/* Assert Slave Select Line 2 */
R_BSP_PinClear(R_BSP_IoRegionGet(SLAVE_SELECT_LINE_2), SLAVE_SELECT_LINE_2);
/* Start a write/read transfer */
g_transfer_complete = false;
err = R_SCI_SPI_WriteRead(&g_spi_ctrl, tx_buffer, rx_buffer, TRANSFER_SIZE, SPI_BIT_WIDTH_8_BITS);
handle_error(err);
/* Wait for SPI_EVENT_TRANSFER_COMPLETE callback event. */
while (false == g_transfer_complete)
{
;
}
/* De-assert Slave Select Line 2 */
R_BSP_PinSet(R_BSP_IoRegionGet(SLAVE_SELECT_LINE_2), SLAVE_SELECT_LINE_2);
}

Data Structures

struct  sci_spi_div_setting_t
 
struct  sci_spi_extended_cfg_t
 
struct  sci_spi_instance_ctrl_t
 

Enumerations

enum  sci_spi_clock_source_t
 

Data Structure Documentation

◆ sci_spi_div_setting_t

struct sci_spi_div_setting_t

Settings for adjusting the SPI CLK.

◆ sci_spi_extended_cfg_t

struct sci_spi_extended_cfg_t

SCI SPI extended configuration

Data Fields
sci_spi_div_setting_t clk_div
sci_spi_clock_source_t clock_source

Clock source to generate SCK can either be selected as PCLKM or SCInASYNCCLK.

◆ sci_spi_instance_ctrl_t

struct sci_spi_instance_ctrl_t

SPI instance control block. DO NOT INITIALIZE.

Enumeration Type Documentation

◆ sci_spi_clock_source_t

Source clock selection options for SCI.

Function Documentation

◆ R_SCI_SPI_Open()

fsp_err_t R_SCI_SPI_Open ( spi_ctrl_t p_ctrl,
spi_cfg_t const *const  p_cfg 
)

Initialize a channel for SPI communication mode. Implements spi_api_t::open.

This function performs the following tasks:

  • Performs parameter checking and processes error conditions.
  • Enables the clock for the SCI channel.
  • Initializes the associated registers with default value and the user-configurable options.
  • Provides the channel handle for use with other API functions.
Parameters
p_ctrlPointer to the control structure.
p_cfgPointer to a configuration structure.
Return values
FSP_SUCCESSChannel initialized successfully.
FSP_ERR_ASSERTIONAn input parameter is invalid or NULL.
FSP_ERR_ALREADY_OPENThe instance has already been opened.
FSP_ERR_IP_CHANNEL_NOT_PRESENTThe channel number is invalid.
FSP_ERR_INVALID_ARGUMENTInvalid input parameter.

◆ R_SCI_SPI_Read()

fsp_err_t R_SCI_SPI_Read ( spi_ctrl_t *const  p_ctrl,
void *  p_dest,
uint32_t const  length,
spi_bit_width_t const  bit_width 
)

Receive data from an SPI device. Implements spi_api_t::read.

The function performs the following tasks:

  • Performs parameter checking and processes error conditions.
  • Enable transmitter.
  • Enable receiver.
  • Enable interrupts.
  • Start data transmission by writing data to the TXD register.
  • Receive data from receive buffer full interrupt occurs and copy data to the buffer of destination.
  • Complete data reception via receive buffer full interrupt and transmitting dummy data.
  • Disable transmitter.
  • Disable receiver.
  • Disable interrupts.
Parameters
p_ctrlPointer to the control structure.
p_destPointer to the destination buffer.
[in]lengthThe number of bytes to transfer.
[in]bit_widthInvalid for SCI_SPI (Set to SPI_BIT_WIDTH_8_BITS).
Return values
FSP_SUCCESSRead operation successfully completed.
FSP_ERR_ASSERTIONOne of the following invalid parameters passed:
  • Pointer p_ctrl is NULL
  • Length is equal to 0
  • Pointer to destination is NULL
FSP_ERR_NOT_OPENThe channel has not been opened. Open the channel first.
FSP_ERR_UNSUPPORTEDThe given bit_width is not supported.
FSP_ERR_IN_USEA transfer is already in progress.
Returns
See Common Error Codes or functions called by this function for other possible return codes. This function calls:

◆ R_SCI_SPI_Write()

fsp_err_t R_SCI_SPI_Write ( spi_ctrl_t *const  p_ctrl,
void const *  p_src,
uint32_t const  length,
spi_bit_width_t const  bit_width 
)

Transmit data to a SPI device. Implements spi_api_t::write.

The function performs the following tasks:

  • Performs parameter checking and processes error conditions.
  • Enable transmitter.
  • Enable interrupts.
  • Start data transmission with data via transmit buffer empty interrupt.
  • Copy data from source buffer to the SPI data register for transmission.
  • Complete data transmission via transmit buffer empty interrupt.
  • Disable transmitter.
  • Disable receiver.
  • Disable interrupts.
Parameters
p_ctrlPointer to the control structure.
p_srcPointer to the source buffer.
[in]lengthThe number of bytes to transfer.
[in]bit_widthInvalid for SCI_SPI (Set to SPI_BIT_WIDTH_8_BITS).
Return values
FSP_SUCCESSWrite operation successfully completed.
FSP_ERR_ASSERTIONOne of the following invalid parameters passed:
  • Pointer p_ctrl is NULL
  • Pointer to source is NULL
  • Length is equal to 0
FSP_ERR_NOT_OPENThe channel has not been opened. Open the channel first.
FSP_ERR_UNSUPPORTEDThe given bit_width is not supported.
FSP_ERR_IN_USEA transfer is already in progress.
Returns
See Common Error Codes or functions called by this function for other possible return codes. This function calls:

◆ R_SCI_SPI_WriteRead()

fsp_err_t R_SCI_SPI_WriteRead ( spi_ctrl_t *const  p_ctrl,
void const *  p_src,
void *  p_dest,
uint32_t const  length,
spi_bit_width_t const  bit_width 
)

Simultaneously transmit data to SPI device while receiving data from SPI device (full duplex). Implements spi_api_t::writeRead.

The function performs the following tasks:

  • Performs parameter checking and processes error conditions.
  • Enable transmitter.
  • Enable receiver.
  • Enable interrupts.
  • Start data transmission using transmit buffer empty interrupt (or by writing to the TDR register).
  • Copy data from source buffer to the SPI data register for transmission.
  • Receive data from receive buffer full interrupt and copy data to the destination buffer.
  • Complete data transmission and reception via transmit end interrupt.
  • Disable transmitter.
  • Disable receiver.
  • Disable interrupts.
Parameters
p_ctrlPointer to the control structure.
p_srcPointer to the source buffer.
p_destPointer to the destination buffer.
[in]lengthThe number of bytes to transfer.
[in]bit_widthInvalid for SCI_SPI (Set to SPI_BIT_WIDTH_8_BITS).
Return values
FSP_SUCCESSWrite operation successfully completed.
FSP_ERR_ASSERTIONOne of the following invalid parameters passed:
  • Pointer p_ctrl is NULL
  • Pointer to source is NULL
  • Pointer to destination is NULL
  • Length is equal to 0
FSP_ERR_NOT_OPENThe channel has not been opened. Open the channel first.
FSP_ERR_UNSUPPORTEDThe given bit_width is not supported.
FSP_ERR_IN_USEA transfer is already in progress.
Returns
See Common Error Codes or functions called by this function for other possible return codes. This function calls:

◆ R_SCI_SPI_Close()

fsp_err_t R_SCI_SPI_Close ( spi_ctrl_t *const  p_ctrl)

Disable the SCI channel and set the instance as not open. Implements spi_api_t::close.

Parameters
p_ctrlPointer to an opened instance.
Return values
FSP_SUCCESSChannel successfully closed.
FSP_ERR_ASSERTIONThe parameter p_ctrl is NULL.
FSP_ERR_NOT_OPENThe channel has not been opened. Open the channel first.

◆ R_SCI_SPI_CalculateBitrate()

fsp_err_t R_SCI_SPI_CalculateBitrate ( uint32_t  bitrate,
sci_spi_clock_source_t  clock_source,
sci_spi_div_setting_t sclk_div 
)

Calculate the register settings required to achieve the desired bitrate.

Parameters
[in]bitratebitrate [bps]. For example, 250,000; 500,00; 2,500,000; etc.
clock_sourceclock source (PCLKM or SCInASYNCCLK) used for bit rate calculation.
sclk_divPointer to sci_spi_div_setting_t used to configure baudrate settings.
Return values
FSP_SUCCESSBaud rate is set successfully.
FSP_ERR_ASSERTIONBaud rate is not achievable.
Note
The application must pause for 1 bit time after the BRR register is loaded before transmitting/receiving to allow time for the clock to settle.

◆ R_SCI_SPI_CallbackSet()

fsp_err_t R_SCI_SPI_CallbackSet ( spi_ctrl_t *const  p_ctrl,
void(*)(spi_callback_args_t *)  p_callback,
void const *const  p_context,
spi_callback_args_t *const  p_callback_memory 
)

Updates the user callback and has option of providing memory for callback structure. Implements spi_api_t::callbackSet

Return values
FSP_SUCCESSCallback updated successfully.
FSP_ERR_ASSERTIONA required pointer is NULL.
FSP_ERR_NOT_OPENThe control block has not been opened.