SPI Library

The SPI module is available with all ARM MCUs. mikroC PRO for ARM provides a library for initializing the Slave mode and initializing and comfortable work with the Master mode. The ARM can easily communicate with other devices via SPI: A/D converters, D/A converters, MAX7219, LTC1290, etc.

Important :

SPI library routines require you to specify the module you want to use. To select the desired SPI module, simply change the letter x in the routine prototype for a number from 0 to 8.
Number of SPI modules per MCU differs from chip to chip. Please, read the appropriate datasheet before utilizing this library.
Switching between the SPI modules in the SPI library is done by the SPI_Set_Active function (both SPI modules have to be previously initialized).

Generic Routines

SPI_Read
SPI_Write

SPIx_Init

Prototype	void SPIx_Init();
Description	Configures and initializes the SPI module with default settings. Default settings for Stellaris MCUs : Master mode. 8-bit data mode. Serial clock set to 2 MHz. Clock idle state low. Serial output data changes on the first clock edge transition. Default settings for MSP432 MCUs : Master mode. 8-bit data mode. Low-speed subsystem master clock as clock source. Serial output data changes on the first clock edge transition. MSB sent first. Default settings for ST MCUs : Master mode. 8-bit data mode. Serial clock set to Peripheral clock/64. Clock idle state low. Serial output data changes on the first clock edge transition. Slave Select output disabled. Software Slave Management disabled. Default settings for CEC1x02 : Master mode. 8-bit data mode. Serial clock set to 1 MHz. Clock idle state low. Serial output data changes on the first clock edge transition. MSB sent first. Default settings for Kinetis : Master mode. 8-bit data mode. Serial clock set to 8 MHz. Clock idle state low. Serial output data changes on the first clock edge transition. MSB sent first.
Parameters	None.
Returns	Nothing.
Requires	MCU must have the SPI module.
Example	// Initialize the SPI1 module with default settings SPI1_Init();
Notes	SPI library routines require you to specify the module you want to use. To select the desired SPI module, simply change the letter x in the routine prototype for a number from 0 to 8. Number of SPI modules per MCU differs from chip to chip. Please, read the appropriate datasheet before utilizing this library. `SPI_Rd_Ptr()` and `SPI_Wr_Ptr()` global function pointers are assigned when a SPI module is initialized. They point to the appropriate read and write routines (determined by the initialized SPI module) so they can be used for SPI read and write operations. Switching between the SPI modules in the SPI library is done by the SPI_Set_Active function (both SPI modules have to be previously initialized). SPI modules are set on the following pins : Stellaris SPI0 : PA2/PA4/PA5 - all Cortex M3 and M4 MCUs. SPI1 : PB5/PE4/PE5 - TM4C129x Cortex M4 MCUs. PD0/PD2/PD3 - all other Cortex M4 MCUs not listed before. PE0/PE2/PE3 - all Cortex M3 MCUs. SPI2 : PG7/PG5/PG4 - TM4C129x Cortex M4 MCUs. PH4/PH6/PH7 - LM4F112x, LM4F122x, LM4F132x, LM4F212x and LM4F232x Cortex M4 MCUs. PB4/PB5/PB7 - all other Cortex M4 MCUs not listed before. SPI3 : PQ0/PQ2/PQ3 - TM4C129x Cortex M4 MCUs. PH0/PH2/PH3 - LM4F112x, LM4F122x, LM4F132x, LM4F212x and LM4F232x Cortex M4 MCUs. PD0/PD2/PD3 - all other Cortex M4 MCUs not listed before. MSP432 SPI1 : PA1/PA2/PA3. SPI2 : PA9/PA10/PA11. SPI3 : PB1/PB2/PB3. SPI4 : PE5/PE6/PE7. SPI5 : PA5/PA6/PA7. SPI6 : PC11/PC13/PC12. SPI7 : PB5/PB6/PB7. SPI8 : PE9/PE10/PE11. STM32 SPI1 : PA5/PA6/PA7 - all Cortex M0, M3 and M4 MCUs. SPI2 : PB10/PB14/PB15 - STM32F373x/STM32F378x/STM32F383x Cortex M4 MCUs. PB13/PB14/PB15 - all Cortex M0, M3 and other Cortex M4 MCUs not listed before. SPI3 : PB3/PB4/PB5 - all Cortex M3 and M4 MCUs. SPI4 : PE2/PE5/PE6 - all Cortex M3 and M4 MCUs. SPI5 : PB0/PA12/PA10 - STM32F411x Cortex M4 MCUs. PF7/PF8/PF9 - all other Cortex M4 MCUs not listed before. SPI6 : PG12/PG13/PG14 - all Cortex M4 MCUs. CEC1302 SPI0 : P153/P164/P054 CEC1702 SPI0 : P034/P036/P001 Kinetis SPI0 : PD1/PD3/PD2 SPI1 : PD5/PD7/PD6 SPI2 : PB21/PB23/PB22

SPIx_Init_Advanced

Prototype

// for Stellaris MCUs :

void SPIx_Init_Advanced(unsigned long bit_rate_Hz, unsigned master_slave_mode, unsigned config);

// for Stellaris MCUs with alternative PORT functions on GPIO pins :

void SPIx_Init_Advanced(unsigned long bit_rate_Hz, unsigned master_slave_mode, unsigned config, const Module_Struct *module);

// for MCP432 MCUs :

void SPIx_Init_Advanced(int mst, int clkDiv, int clkSource, int msbFirst, int clkPhase, int clkPolarity, int spiMode, const Module_Struct *module);

// for ST MCUs :

void SPIx_Init_Advanced(char clock_divider, long config, const Module_Struct *module);

// for CEC1x02 :

void SPI0_Init_Advanced(unsigned long bit_rate_Hz, unsigned lsb_first, unsigned char config);

// for Kinetis :

void SPI0_Init_Advanced(unsigned long baudRate, unsigned long config, Module_Struct* module);

Description

Configures and initializes the SPI module with user defined settings.

Parameters

Stellaris

The bit_rate_Hz parameter determines the SPI clock value in Hz.
The master_slave_mode parameter determines the working mode for SPI module.

Master/Slave mode

Description Predefined library const

Master mode _SPI_MASTER

Slave mode _SPI_SLAVE

The parameter config determines the data size, clock polarity and clock phase.
This value is deriven from OR-ing the following constants :

Data Length Size
Description	Predefined library const
`4-bit data size`	`_SPI_4_BIT`
`5-bit data size`	`_SPI_5_BIT`
`6-bit data size`	`_SPI_6_BIT`
`7-bit data size`	`_SPI_7_BIT`
`8-bit data size`	`_SPI_8_BIT`
`9-bit data size`	`_SPI_9_BIT`
`10-bit data size`	`_SPI_10_BIT`
`11-bit data size`	`_SPI_11_BIT`
`12-bit data size`	`_SPI_12_BIT`
`13-bit data size`	`_SPI_13_BIT`
`14-bit data size`	`_SPI_14_BIT`
`15-bit data size`	`_SPI_15_BIT`
`16-bit data size`	`_SPI_16_BIT`

Clock Polarity
Description	Predefined library const
`IDLE state is Lo, ACTIVE state is Hi`	`_SPI_CLK_IDLE_LOW`
`IDLE state is Hi, ACTIVE state is Lo`	`_SPI_CLK_IDLE_HIGH`

Clock Phase
Description	Predefined library const
`Data is sampled on the first clock edge transition`	`_SPI_FIRST_CLK_EDGE_TRANSITION`
`Data is sampled on the second clock edge transition`	`_SPI_SECOND_CLK_EDGE_TRANSITION`

module: appropriate module pinout. Use Code Assistant to list available module pinouts by typing _GPIO_MODULE_SPI and pressing Ctrl + Space.

MSP432

The mst parameter determines the working mode for SPI module. Valid values :

Description Predefined library const

Master mode _SPI_MASTER

Slave mode _SPI_SLAVE

The clkDiv parameter determines the working clock for SPI module. Valid values are from 1 to 65535.

clockSource: clock source for SPI module. Valid values :

Description Predefined library const

Auxiliary clock _SPI_CLOCKSOURCE_ACLK

Low-speed subsystem master clock _SPI_CLOCKSOURCE_SMCLK

msbFirst: most/least significant bit first. Valid values :

Description Predefined library const

Most significant bit first _SPI_MSB_FIRST

Least significant bit first _SPI_LSB_FIRST

clkPhase: clock phase. Valid values :

Description	Predefined library const
`Data is changed on the first clock edge and captured on the following edge`	`_SPI_PHASE_DATA_CHANGE_FIRST_CAPTURE_NEXT`
`Data is captured on the first clock edge and changed on the following edge.`	`_SPI_PHASE_DATA_CAPTURE_FIRST_CHANGE_NEXT`

clkPolarity: clock polarity. Valid values :

Description Predefined library const

The inactive state is low _SPI_CLK_IDLE_LOW

The inactive state is high _SPI_CLK_IDLE_HIGH

spiMode: 3 wire or 4 wire SPI. Valid values :

Description	Predefined library const
`3-pin SPI`	`_SPI_3PIN`
`4-pin SPI with UCxSTE active high: Slave enabled when UCxSTE = 1`	`_SPI_4PIN_UCxSTE_ACTIVE_HIGH`
`4-pin SPI with UCxSTE active low: Slave enabled when UCxSTE = 0`	`_SPI_4PIN_UCxSTE_ACTIVE_LOW`

module: appropriate module pinout. Use Code Assistant to list available module pinouts by typing _GPIO_MODULE_SPI and pressing Ctrl + Space.

STM32

The clock_divider parameter determines the clock for SPI module (ST specifics).

SPI Clock
Description	Predefined library const
`Peripheral Clock/2`	`_SPI_FPCLK_DIV2`
`Peripheral Clock/4`	`_SPI_FPCLK_DIV4`
`Peripheral Clock/8`	`_SPI_FPCLK_DIV8`
`Peripheral Clock/16`	`_SPI_FPCLK_DIV16`
`Peripheral Clock/32`	`_SPI_FPCLK_DIV32`
`Peripheral Clock/64`	`_SPI_FPCLK_DIV64`
`Peripheral Clock/128`	`_SPI_FPCLK_DIV128`
`Peripheral Clock/256`	`_SPI_FPCLK_DIV256`

The parameter config determines the data size, clock polarity and clock phase.
This value is deriven from OR-ing the following constants :

Data Length Size
Description	Predefined library const
`8-bit data size`	`_SPI_8_BIT`
`16-bit data size`	`_SPI_16_BIT`

Master/Slave mode
Description	Predefined library const
`Master mode`	`_SPI_MASTER`
`Slave mode`	`_SPI_SLAVE`

Clock Polarity
Description	Predefined library const
`IDLE state is Lo, ACTIVE state is Hi`	`_SPI_CLK_IDLE_LOW`
`IDLE state is Hi, ACTIVE state is Lo`	`_SPI_CLK_IDLE_HIGH`

Clock Phase
Description	Predefined library const
`Data is sampled on the first clock edge transition`	`_SPI_FIRST_CLK_EDGE_TRANSITION`
`Data is sampled on the second clock edge transition`	`_SPI_SECOND_CLK_EDGE_TRANSITION`

Bit Sending Hierarchy
Description	Predefined library const
`Most Significant Bit (MSB) sent first`	`_SPI_MSB_FIRST`
`Least Significant Bit (MSB) sent first`	`_SPI_LSB_FIRST`

Software Slave Management
Description	Predefined library const
`Software Slave Management Enable`	`_SPI_SSM_ENABLE`
`Software Slave Management Disable`	`_SPI_SSM_DISABLE`

Slave Select Output
Description	Predefined library const
`Slave Select Output Enable`	`_SPI_SS_ENABLE`
`Slave Select Output Disable`	`_SPI_SS_DISABLE`

Internal Slave Select
Description	Predefined library const
`Internal Slave Select = 0`	`_SPI_SSI_0`
`Internal Slave Select = 1`	`_SPI_SSI_1`

module: appropriate module pinout. Use Code Assistant to list available module pinouts by typing _GPIO_MODULE_SPI and pressing Ctrl + Space.

CEC1x02

The bit_rate_Hz parameter determines the clock for SPI module in Hz.
The parameter lsb_first determines the bit numbering. Valid values:

Description Predefined library const

MSB sent first _SPI_MSB_FIRST

LSB sent first _SPI_LSB_FIRST
The parameter config determines the clock polarity and clock phase. This value is deriven from OR-ing the following constants :

Clock Polarity

Description Predefined library const

IDLE state is Lo, ACTIVE state is Hi _SPI_CLK_IDLE_LOW

IDLE state is Hi, ACTIVE state is Lo _SPI_CLK_IDLE_HIGH

Clock Phase

Description Predefined library const

Data is sampled on the rising clock edge _SPI_SAMPLE_DATA_RISING_EDGE

Data is sampled on the falling clock edge _SPI_SAMPLE_DATA_FALLING_EDGE

Kinetis

The baudRate parameter determines the clock for SPI module (ST specifics).

The parameter config determines the data size, clock polarity and clock phase.
This value is deriven from OR-ing the following constants :

Data Length Size
Description	Predefined library const
`4-bit data size`	`_SPI_CFG_FRAME_SIZE_4BITS`
`5-bit data size`	`_SPI_CFG_FRAME_SIZE_5BITS`
`6-bit data size`	`_SPI_CFG_FRAME_SIZE_6BITS`
`7-bit data size`	`_SPI_CFG_FRAME_SIZE_7BITS`
`8-bit data size`	`_SPI_CFG_FRAME_SIZE_8BITS`
`9-bit data size`	`_SPI_CFG_FRAME_SIZE_9BITS`
`10-bit data size`	`_SPI_CFG_FRAME_SIZE_10BITS`
`11-bit data size`	`_SPI_CFG_FRAME_SIZE_11BITS`
`12-bit data size`	`_SPI_CFG_FRAME_SIZE_12BITS`
`13-bit data size`	`_SPI_CFG_FRAME_SIZE_13BITS`
`14-bit data size`	`_SPI_CFG_FRAME_SIZE_14BITS`
`15-bit data size`	`_SPI_CFG_FRAME_SIZE_15BITS`
`16-bit data size`	`_SPI_CFG_FRAME_SIZE_16BITS`

Master/Slave mode
Description	Predefined library const
`Master mode`	`_SPI_CFG_MASTER`
`Slave mode`	`_SPI_CFG_SLAVE`

Clock Polarity
Description	Predefined library const
`IDLE state is Lo, ACTIVE state is Hi`	`_SPI_CFG_CLK_IDLE_LOW`
`IDLE state is Hi, ACTIVE state is Lo`	`_SPI_CFG_CLK_IDLE_HIGH`

Clock Phase
Description	Predefined library const
`Data is sampled on the first clock edge transition`	`_SPI_CFG_CLK_PHASE_CAPT_LEADING`
`Data is sampled on the second clock edge transition`	`_SPI_CFG_CLK_PHASE_CHG_LEADING`

Bit Sending Hierarchy
Description	Predefined library const
`Most Significant Bit (MSB) sent first`	`_SPI_CFG_MSB_FIRST`
`Least Significant Bit (MSB) sent first`	`_SPI_CFG_LSB_FIRST`

module: appropriate module pinout. Use Code Assistant to list available module pinouts by typing _GPIO_MODULE_SPI and pressing Ctrl + Space.

Returns

Nothing.

Requires

MCU must have the SPI module.

Example

Stellaris

// Set SPI1 to the Master Mode, data length is 16-bit, clock = 2MHz, clock IDLE state high and data transmitted at the first clock edge transition :
SPI1_Init_Advanced(2000000, _SPI_MASTER, _SPI_16_BIT | _SPI_CLK_IDLE_HIGH | _SPI_FIRST_CLK_EDGE_TRANSITION);

// Set SPI1 to the Master Mode, data length is 16-bit, clock = 2MHz, clock IDLE state high and data transmitted at the first clock edge transition, on GPIO_PORTE :
SPI1_Init_Advanced(2000000, _SPI_MASTER, _SPI_16_BIT | _SPI_CLK_IDLE_HIGH | _SPI_FIRST_CLK_EDGE_TRANSITION, &_GPIO_MODULE_SPI1_E023);

MSP432

// Set SPI1 to the Master Mode, 3-pin interface, SMCLK divided by 6, MSB transmitted first, Data is changed on the first UCLK edge and captured on the following edge, inactive state is low :
SPI1_Init_Advanced(_SPI_MASTER, 6, _SPI_CLOCKSOURCE_SMCLK, _SPI_MSB_FIRST, _SPI_PHASE_DATA_CHANGE_FIRST_CAPTURE_NEXT, _SPI_CLK_IDLE_LOW, _SPI_3PIN, _GPIO_MODULE_SPIA0_A123);

STM32

// Set SPI1 to the Master Mode, data length is 8-bit, clock = Peripheral/64, clock IDLE state low and data transmitted at the first clock edge transition, MSB transferred first, Slave Select Disabled :
SPI1_Init_Advanced(_SPI_FPCLK_DIV64, _SPI_MASTER | _SPI_8_BIT | _SPI_CLK_IDLE_LOW | _SPI_FIRST_CLK_EDGE_TRANSITION | _SPI_MSB_FIRST | _SPI_SS_DISABLE | _SPI_SSM_ENABLE | _SPI_SSI_1, &_GPIO_MODULE_SPI1_PA567);

CEC1x02

// Set SPI0 with clock = 1MHz, MSB sent first, clock IDLE state low and data transmitted at the rising clock edge transition :
SPI0_Init_Advanced(1000000,  _SPI_MSB_FIRST, _SPI_CLK_IDLE_LOW | _SPI_SAMPLE_DATA_RISING_EDGE);

Kinetis

// Set SPI1 to the Master Mode, data length is 8-bit, clock = 8 MHz, clock IDLE state low and data transmitted at the first clock edge transition, MSB transferred first :
SPI1_Init_Advanced(8000000, _SPI_CFG_MASTER | _SPI_CFG_FRAME_SIZE_8BITS | _SPI_CFG_CLK_IDLE_LOW | _SPI_CFG_CLK_PHASE_CAPT_LEADING | _SPI_CFG_MSB_FIRST, &_GPIO_Module_SPI0_PD1_3_2);

Notes

SPI library routines require you to specify the module you want to use. To select the desired SPI module, simply change the letter x in the routine prototype for a number from 0 to 8.
Number of SPI modules per MCU differs from chip to chip. Please, read the appropriate datasheet before utilizing this library.
SPI_Rd_Ptr() and SPI_Wr_Ptr() global function pointers are assigned when a SPI module is initialized. They point to the appropriate read and write routines (determined by the initialized SPI module) so they can be used for SPI read and write operations.
Switching between the SPI modules in the SPI library is done by the SPI_Set_Active function (both SPI modules have to be previously initialized).
For available working modes for a specific MCU please read the appropriate datasheet.

SPIx_Read

Prototype	unsigned SPIx_Read(unsigned long buffer);
Description	Reads one word from the SPI bus.
Parameters	`buffer:` dummy data for clock generation (see device Datasheet for SPI modules implementation details)
Returns	Received data.
Requires	Routine requires at least one SPI module. Used SPI module must be initialized before using this function. See the SPIx_Init and SPIx_Init_Advanced routines.
Example	// read a byte from the SPI bus char take, buffer; ... take = SPI1_Read(buffer);
Notes	SPI library routines require you to specify the module you want to use. To select the desired SPI module, simply change the letter x in the routine prototype for a number from 0 to 8. Number of SPI modules per MCU differs from chip to chip. Please, read the appropriate datasheet before utilizing this library.

SPIx_Write

Prototype	void SPIx_Write(unsigned data_out);
Description	Writes one word via the SPI bus.
Parameters	`data_out:` data to be sent
Returns	Nothing.
Requires	Routine requires at least one SPI module. Used SPI module must be initialized before using this function. See the SPIx_Init and SPIx_Init_Advanced routines.
Example	// write a buffer to the SPI bus unsigned buffer; ... SPI1_Write(buffer);
Notes	SPI library routines require you to specify the module you want to use. To select the desired SPI module, simply change the letter x in the routine prototype for a number from 0 to 8. Number of SPI modules per MCU differs from chip to chip. Please, read the appropriate datasheet before utilizing this library.

SPI_Set_Active

Prototype	void SPI_Set_Active(unsigned (read_ptr)(unsigned), void(write_ptr)(unsigned));
Description	Sets the active SPI module which will be used by the SPIx_Read and SPIx_Write routines.
Parameters	Parameters : `read_ptr:` SPI1_Read handler `write_ptr:` SPI1_Write handler
Returns	Nothing.
Requires	Routine is available only for MCUs with multiple SPI modules. Used SPI module must be initialized before using this function. See the SPIx_Init and SPIx_Init_Advanced routines.
Example	SPI_Set_Active(SPI1_Read, SPI1_Write); // Sets the SPI1 module active
Notes	Number of SPI modules per MCU differs from chip to chip. Please, read the appropriate datasheet before utilizing this library.

SPI_Read

Prototype	unsigned int SPI_Read(unsigned int buffer);
Description	Reads one word or byte from the SPI bus. This is a generic routine which uses the active SPI module previously activated by the SPI_Set_Active routine.
Parameters	`buffer:` dummy data for clock generation (see device Datasheet for SPI modules implementation details)
Returns	Received data.
Requires	Routine requires at least one SPI module. Used SPI module must be initialized before using this function. See the SPIx_Init and SPIx_Init_Advanced routines.
Example	// read a word from the SPI bus unsigned int take, buffer; ... take = SPI_Read(buffer);
Notes	None.

SPI_Write

Prototype	procedure SPI_Write(data_out : word);
Description	Writes one word or byte via the SPI bus. This is a generic routine which uses the active SPI module previously activated by the SPI_Set_Active routine.
Parameters	`data_out:` data to be sent
Returns	Nothing.
Requires	Routine requires at least one SPI module. Used SPI module must be initialized before using this function. See the SPIx_Init and SPIx_Init_Advanced routines.
Example	// write a word to the SPI bus unsigned int buffer; ... SPI_Write(buffer);
Notes	None.

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SPI Library

Library Routines

Generic Routines

SPIx_Init

Stellaris

MSP432

STM32

CEC1302

CEC1702

Kinetis

SPIx_Init_Advanced

Stellaris

MSP432

STM32

CEC1x02

Kinetis

Stellaris

MSP432

STM32

CEC1x02

Kinetis

SPIx_Read

SPIx_Write

SPI_Set_Active

SPI_Read

SPI_Write