CRC (r_crc_w)

Functions
fsp_err_t	R_CRC_W_Open (crc_ctrl_t *const p_ctrl, crc_cfg_t const *const p_cfg)
fsp_err_t	R_CRC_W_Close (crc_ctrl_t *const p_ctrl)
fsp_err_t	R_CRC_W_Calculate (crc_ctrl_t *const p_ctrl, crc_input_t *const p_crc_input, uint32_t *p_calculatedValue)
fsp_err_t	R_CRC_W_CalculatedValueGet (crc_ctrl_t *const p_ctrl, uint32_t *p_calculatedValue)
fsp_err_t	R_CRC_W_SnoopEnable (crc_ctrl_t *const p_ctrl, uint32_t crc_seed)
fsp_err_t	R_CRC_W_SnoopDisable (crc_ctrl_t *const p_ctrl)

Detailed Description

Driver for the CRC peripheral on RA6W1/RA6W2 MCUs. This module implements the CRC Interface.

Overview

The CRC module provides an API to calculate 16 and 32-bit CRC values on a block of data in memory or a data being transferred by the bus master (DMA) using industry-standard polynomials.

Features

• Support 8-bit, 16-bit, and 32-bit data paths.
• Be a master on the bus and can operate over a region of memory independent of the CPU.
• Support various methods of calculating the CRC as defined by the following generator polynomials.
  • X^16+X^15+X^2+1 (CRC-16-IBM)
  • X^16+X^12+X^5+1 (CRC-16-CCITT)
  • X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X+ 1 (CRC-32)
  • X^32+X^28+X^27+X^26+X^25+X^23+X^22+X^20+X^19+X^18+X^14+X^13+X^11+X^10+X^9+X^8+X^6+1 (CRC-32C)

Configuration

Build Time Configurations for r_crc_w

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

Configuration	Options	Default	Description
Parameter Checking	Default (BSP) Enabled Disabled	Default (BSP)	If selected code for parameter checking is included in the build.
DMAC Support	Enabled Disabled	Disabled	If enabled, DMAC instance will be included in the build.

Configurations for Monitoring > CRC (r_crc_w)

This module can be added to the Stacks tab via New Stack > Monitoring > CRC (r_crc_w).

Configuration	Options	Default	Description
Name	Name must be a valid C symbol	g_crc0	Module name.
Channel	Value must be a non-negative integer	0	Specifies the CRC calculation channel.
CRC Polynomial	CRC-32 CRC-32C CRC-16 CCITT CRC-16 IBM	CRC-32	Select the CRC polynomial.
Input Data Swap Enable	Normal Byte Swap	Normal	Input data swap enable.
Bit Endian Type	Big Endian Little Endian	Big Endian	Bit endian type.
Parallel Type	8 bits 16 bits 32 bits	8 bits	Parallel type of CRC calculation.
Access Type	Read access Write access	Read access	Access type of CRC calculation.

Clock Configuration

There is no clock configuration for the CRC module.

Pin Configuration

This module does not use I/O pins.

Usage Notes

Limitations

When using CRC32 polynomial functions the CRC module produces the same results as popular online CRC32 calculators, but it is important to remember a few important points.

• Online CRC32 calculators usually invert the output prior to presenting it as a result. It is up to the application program to include this step if needed.
• The seed value of 0xFFFFFFFF needs to be used by both the online calculator and the R_CRC module API (CRC32 polynomials)
• Some online CRC tools XOR the final result with 0xFFFFFFFF.

Examples

Basic Example

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

void crc_basic_example (void)
{
    uint32_t length;
    uint32_t calculated_value;

    length = sizeof(g_crc_data) / sizeof(g_crc_data[0]);

    crc_input_t example_input =
    {
        .p_input_buffer = g_crc_data,
        .num_bytes      = length,
        .crc_seed       = 0,
    };

    /* Open CRC module */
    R_CRC_W_Open(&g_crc_ctrl, &g_crc_cfg);

    /* CRC calculation and Read CRC value */
    R_CRC_W_Calculate(&g_crc_ctrl, &example_input, &calculated_value);
}

DMA Example

This example demonstrates CRC DMA operation.

void g_dmac_callback (dmac_callback_args_t * cb_data)
{
    FSP_PARAMETER_NOT_USED(cb_data);
    g_dmac_transfer_complete = true;
}

void crc_dma_example (void)
{
    uint32_t length;
    uint32_t calculated_value;

    length = sizeof(g_crc_data) / sizeof(g_crc_data[0]);

    crc_input_t example_input =
    {
        .p_input_buffer = g_crc_data,
        .num_bytes      = length,
        .crc_seed       = 0,
    };

    g_dmac_transfer_complete = false;

    /* Open CRC module */
    R_CRC_W_Open(&g_crc_ctrl, &g_crc_cfg);

    /* CRC calculation */
    R_CRC_W_Calculate(&g_crc_ctrl, &example_input, NULL);

    while (!g_dmac_transfer_complete);

    /* Read CRC value */
    R_CRC_W_CalculatedValueGet(&g_crc_ctrl, &calculated_value);
}

Data Structures
struct	crc_w_instance_ctrl_t
struct	crc_w_extended_cfg_t

Enumerations
enum	crc_w_channel_t
enum	crc_w_polynomial_t
enum	crc_w_path_selection_t
enum	crc_w_swap_enable_t
enum	crc_w_endian_type_t
enum	crc_w_parallel_type_t
enum	crc_w_access_type_t
enum	crc_w_calculation_status_t
enum	crc_w_remap_address_0_t

---

Data Structure Documentation

crc_w_instance_ctrl_t

struct crc_w_instance_ctrl_t

Driver instance control structure.

Data Fields
uint32_t	open	Whether or not driver is open.
const crc_cfg_t *	p_cfg	Pointer to initial configuration.

crc_w_extended_cfg_t

struct crc_w_extended_cfg_t

Extended configuration.

Data Fields
crc_w_channel_t	channel	CRC channel.
crc_w_polynomial_t	polynomial	CRC Generating Polynomial.
crc_w_swap_enable_t	swap_enable	Input Data Swap Enable.
crc_w_endian_type_t	endian_type	Bit Endian Type.
crc_w_parallel_type_t	parallel_type	Parallel Type of CRC Calculation.
crc_w_access_type_t	access_type	Access Type of CRC Calculation.
crc_w_path_selection_t	path_selection	Path Selection of CRC Calculation.
transfer_instance_t const *	p_transfer	DMAC instance. Set to NULL if unused.

Enumeration Type Documentation

crc_w_channel_t

enum crc_w_channel_t

CRC channel.

Enumerator
CRC_W_CHANNEL_0	CRC channel 0.
CRC_W_CHANNEL_1	CRC channel 1.

crc_w_polynomial_t

enum crc_w_polynomial_t

CRC Generating Polynomial.

Enumerator
CRC_W_POLYNOMIAL_CRC_32	32-bit CRC-32 X^32 + X^26 + X^23 + X^22 + X^16 + X^12 + X^11 + X^10 + X^8 + X^7 + X^5 + X^4 + X^2 + X + 1
CRC_W_POLYNOMIAL_CRC_32C	32-bit CRC-32C X^32 + X^28 + X^27 + X^26 + X^25 + X^23 + X^22 + X^20 + X^19 + X^18 + X^14 + X^13 + X^11 + X^10 + X^9 + X^8 + X^6 + 1
CRC_W_POLYNOMIAL_CRC_16_CCITT	16-bit CRC-16-CCITT X^16 + X^12 + X^5 + 1
CRC_W_POLYNOMIAL_CRC_16_IBM	16-bit CRC-16-IBM X^16 + X^15 + X^2 + 1

crc_w_path_selection_t

enum crc_w_path_selection_t

Enumerator
CRC_W_PATH_SELECT_CPU	CPU.
CRC_W_PATH_SELECT_DMA	DMA.

crc_w_swap_enable_t

enum crc_w_swap_enable_t

Enumerator
CRC_W_SWAP_NORMAL	Data swap normal.
CRC_W_SWAP_BYTE	Data swap byte.

crc_w_endian_type_t

enum crc_w_endian_type_t

Enumerator
CRC_W_ENDIAN_BIG	Big endian.
CRC_W_ENDIAN_LITTLE	Little endian.

crc_w_parallel_type_t

enum crc_w_parallel_type_t

Enumerator
CRC_W_PARALLEL_TYPE_8	8 bit
CRC_W_PARALLEL_TYPE_16	16 bit
CRC_W_PARALLEL_TYPE_32	32 bit

crc_w_access_type_t

enum crc_w_access_type_t

Enumerator
CRC_W_ACCESS_TYPE_READ	Read access.
CRC_W_ACCESS_TYPE_WRITE	Write access.

crc_w_calculation_status_t

enum crc_w_calculation_status_t

Enumerator
CRC_W_CAL_STATUS_IDLE	CRC calculation status idle.
CRC_W_CAL_STATUS_BUSY	CRC calculation status busy.
CRC_W_CAL_STATUS_STOP	CRC calculation status stop.
CRC_W_CAL_STATUS_ERROR	CRC calculation status error.

crc_w_remap_address_0_t

enum crc_w_remap_address_0_t

Remap address 0.

Enumerator
CRC_W_REMAP_ADDRESS_0_TO_ROM	ROM.
CRC_W_REMAP_ADDRESS_0_TO_OQSPI_FLASH	OQSPI.
CRC_W_REMAP_ADDRESS_0_TO_RAM	RAM.

Function Documentation

R_CRC_W_Open()

fsp_err_t R_CRC_W_Open	(	crc_ctrl_t *const	p_ctrl,
		crc_cfg_t const *const	p_cfg
	)

Open the CRC driver module

Implements crc_api_t::open

Open the CRC driver module and initialize the driver control block according to the passed-in configuration structure.

Return values

FSP_SUCCESS	Configuration was successful.
FSP_ERR_ASSERTION	p_ctrl or p_cfg is NULL.
FSP_ERR_ALREADY_OPEN	Module already open
FSP_ERR_TIMEOUT	CRC is busy.

Returns

See Common Error Codes for other possible return codes. This function internally calls transfer_api_t::open.

R_CRC_W_Close()

fsp_err_t R_CRC_W_Close

(

crc_ctrl_t *const

p_ctrl

)

Close the CRC module driver.

Implements crc_api_t::close

Return values

FSP_SUCCESS	Configuration was successful.
FSP_ERR_ASSERTION	p_ctrl is NULL. Status of CRC calculation is ERROR.
FSP_ERR_NOT_OPEN	The driver is not opened.
FSP_ERR_TIMEOUT	CRC is not stopped.

R_CRC_W_Calculate()

fsp_err_t R_CRC_W_Calculate	(	crc_ctrl_t *const	p_ctrl,
		crc_input_t *const	p_crc_input,
		uint32_t *	p_calculatedValue
	)

Perform a CRC calculation on a block of data.

Implements crc_api_t::calculate

If not using DMA, returns the calculated CRC value. If using DMA, use R_CRC_W_CalculatedValueGet to get the calculated value.

Return values

FSP_SUCCESS	Calculation successful.
FSP_ERR_ASSERTION	Either p_ctrl, inputBuffer, or p_calculatedValue is NULL. Status of CRC calculation is ERROR.
FSP_ERR_INVALID_ARGUMENT	length value is NULL.
FSP_ERR_NOT_OPEN	The driver is not opened.
FSP_ERR_TIMEOUT	CRC is not stopped. CRC is busy.

R_CRC_W_CalculatedValueGet()

fsp_err_t R_CRC_W_CalculatedValueGet	(	crc_ctrl_t *const	p_ctrl,
		uint32_t *	p_calculatedValue
	)

Return the calculated value.

Implements crc_api_t::crcResultGet

CRC calculation operates on a running value. This function returns the current calculated value.

Return values

FSP_SUCCESS	Return of calculated value successful.
FSP_ERR_ASSERTION	Either p_ctrl or p_calculatedValue is NULL.
FSP_ERR_NOT_OPEN	The driver is not opened.
FSP_ERR_TIMEOUT	CRC calculation is not stopped.

R_CRC_W_SnoopEnable()

fsp_err_t R_CRC_W_SnoopEnable	(	crc_ctrl_t *const	p_ctrl,
		uint32_t	crc_seed
	)

Configure the snoop channel and set the CRC seed.

Implements crc_api_t::snoopEnable

The CRC calculator can operate on reads and writes over any of the first ten SCI channels. For example, if set to channel 0, transmit, every byte written out SCI channel 0 is also sent to the CRC calculator as if the value was explicitly written directly to the CRC calculator.

Return values

FSP_ERR_UNSUPPORTED

SNOOP operation is not supported.

R_CRC_W_SnoopDisable()

fsp_err_t R_CRC_W_SnoopDisable

(

crc_ctrl_t *const

p_ctrl

)

Disable snooping.

Implements crc_api_t::snoopDisable

Return values

FSP_ERR_UNSUPPORTED

SNOOP operation is not supported.