I2C

EMLIB

Use 10 bit address.

Definition at line 160 of file em_i2c.h .

Referenced by I2C_Transfer() .

Indicate plain read sequence: S+ADDR(R)+DATA0+P.

• S - Start
• ADDR(R) - Address with W/R bit set
• DATA0 - Data read into buffer with index 0
• P - Stop

Definition at line 133 of file em_i2c.h .

Referenced by controllerRead() , I2C_Transfer() , I2C_TransferInit() , and SI7021_cmdRead() .

Indicate plain write sequence: S+ADDR(W)+DATA0+P.

• S - Start
• ADDR(W) - address with W/R bit cleared
• DATA0 - Data taken from buffer with index 0
• P - Stop

Definition at line 122 of file em_i2c.h .

Referenced by CCS811_setEnvData() , CCS811_setMeasureMode() , CCS811_softwareReset() , controllerRead() , EEPROM_AckPoll() , I2C_Transfer() , SI1133_registerBlockWrite() , SI1133_registerWrite() , Si1147_Write_Block_Register() , Si1147_Write_Register() , Si114x_i2c_smbus_write_byte_data() , Si114x_i2c_smbus_write_i2c_block_data() , SI7021_cmdWrite() , SI7210_wakeUp() , Si72xx_WakeUpAndIdle() , Si72xx_Write_Register() , and TEMPSENS_RegisterSet() .

Indicate combined write/read sequence: S+ADDR(W)+DATA0+Sr+ADDR(R)+DATA1+P.

• S - Start
• Sr - Repeated start
• ADDR(W) - Address with W/R bit cleared
• ADDR(R) - Address with W/R bit set
• DATAn - Data written from/read into buffer with index n
• P - Stop

Definition at line 146 of file em_i2c.h .

Referenced by CCS811_getMeasurement() , CCS811_getRawData() , CCS811_readMailbox() , EEPROM_Read() , I2C_Transfer() , I2C_TransferInit() , SI1133_registerBlockRead() , SI1133_registerRead() , Si1147_Read_Block_Register() , Si1147_Read_Register() , Si114x_i2c_smbus_read_byte_data() , Si114x_i2c_smbus_read_i2c_block_data() , Si7013_Detect() , Si7013_GetFirmwareRevision() , SI7021_cmdRead() , SI7210_registerRead() , Si72xx_Read_Register() , sl_efp_read_register() , and TEMPSENS_RegisterGet() .

Indicate write sequence using two buffers: S+ADDR(W)+DATA0+DATA1+P.

• S - Start
• ADDR(W) - Address with W/R bit cleared
• DATAn - Data written from buffer with index n
• P - Stop

Definition at line 157 of file em_i2c.h .

Referenced by EEPROM_Write() , SI7021_cmdWrite() , SI7210_registerWrite() , and sl_efp_write_register() .

Fast mode max frequency assuming using 6:3 ratio for Nlow:Nhigh.

From I2C specification: Min Tlow = 1.3us, min Thigh = 0.6us, max Trise=0.3us, max Tfall=0.3us. Since ratio is 6:3, have to use worst case value of Tlow or 2xThigh as base.

1/(Tlow + Thigh + 0.3us + 0.3us) = 1/(1.3 + 0.65 + 0.6)us = 392157Hz

Definition at line 99 of file em_i2c.h .

Fast mode+ max frequency assuming using 11:6 ratio for Nlow:Nhigh.

From I2C specification: Min Tlow = 0.5us, min Thigh = 0.26us, max Trise=0.12us, max Tfall=0.12us. Since ratio is 11:6, have to use worst case value of Tlow or (11/6)xThigh as base.

1/(Tlow + Thigh + 0.12us + 0.12us) = 1/(0.5 + 0.273 + 0.24)us = 987167Hz

Definition at line 111 of file em_i2c.h .

Referenced by sl_efp_init() .

Standard mode max frequency assuming using 4:4 ratio for Nlow:Nhigh.

From I2C specification: Min Tlow = 4.7us, min Thigh = 4.0us, max Trise=1.0us, max Tfall=0.3us. Since ratio is 4:4, have to use worst case value of Tlow or Thigh as base.

1/(Tlow + Thigh + 1us + 0.3us) = 1/(4.7 + 4.7 + 1.3)us = 93458Hz

Note

Due to chip characteristics, max value is somewhat reduced.

Definition at line 82 of file em_i2c.h .

Suggested default configuration for I2C initialization structure.

Definition at line 219 of file em_i2c.h .

Clock low to high ratio settings.

Definition at line 167 of file em_i2c.h .

Return codes for single master mode transfer function.

Definition at line 174 of file em_i2c.h .

Get the current configured I2C bus frequency.

This frequency is only relevant when acting as master.

Note

The actual frequency is a real number, this function returns a rounded down (truncated) integer value.

Parameters

[in]

i2c

A pointer to the I2C peripheral register block.

Returns

The current I2C frequency in Hz.

Definition at line 202 of file em_i2c.c .

References CMU_ClockFreqGet() , cmuClock_I2C0 , and cmuClock_I2C1 .

Set the I2C bus frequency.

The bus frequency is only relevant when acting as master. The bus frequency should not be set higher than the maximum frequency accepted by the slowest device on the bus.

Notice that, due to asymmetric requirements on low and high I2C clock cycles in the I2C specification, the maximum frequency allowed to comply with the specification may be somewhat lower than expected.

See the reference manual, details on I2C clock generation, for maximum allowed theoretical frequencies for different modes.

Parameters

[in]	i2c	A pointer to the I2C peripheral register block.
[in]	freqRef	An I2C reference clock frequency in Hz that will be used. If set to 0, HFPERCLK / HFPERCCLK clock is used. Setting it to a higher than actual configured value has the consequence of reducing the real I2C frequency.
[in]	freqScl	A bus frequency to set (bus speed may be lower due to integer prescaling). Safe (according to the I2C specification) maximum frequencies for standard fast and fast+ modes are available using I2C_FREQ_ defines. (Using I2C_FREQ_ defines requires corresponding setting of type .) The slowest slave device on a bus must always be considered.
[in]	i2cMode	A clock low-to-high ratio type to use. If not using i2cClockHLRStandard, make sure all devices on the bus support the specified mode. Using a non-standard ratio is useful to achieve a higher bus clock in fast and fast+ modes.

Definition at line 267 of file em_i2c.c .

References BUS_RegMaskedWrite() , CMU_ClockFreqGet() , cmuClock_I2C0 , cmuClock_I2C1 , i2cClockHLRAsymetric , i2cClockHLRFast , and i2cClockHLRStandard .

Referenced by I2C_Init() .

Enable/disable I2C.

Note

After enabling the I2C (from being disabled), the I2C is in BUSY state.

Parameters

[in]	i2c	A pointer to the I2C peripheral register block.
[in]	enable	True to enable counting, false to disable.

Definition at line 402 of file em_i2c.c .

References BUS_RegBitWrite() .

Referenced by I2C_Init() .

Initialize I2C.

Parameters

[in]	i2c	A pointer to the I2C peripheral register block.
[in]	init	A pointer to the I2C initialization structure.

Definition at line 423 of file em_i2c.c .

References BUS_RegBitWrite() , I2C_Init_TypeDef::clhr , I2C_Init_TypeDef::enable , I2C_Init_TypeDef::freq , I2C_BusFreqSet() , I2C_Enable() , I2C_IntClear() , I2C_Init_TypeDef::master , and I2C_Init_TypeDef::refFreq .

Referenced by I2CSPM_Init() .

Clear one or more pending I2C interrupts.

Parameters

[in]	i2c	Pointer to I2C peripheral register block.
[in]	flags	Pending I2C interrupt source to clear. Use a bitwise logic OR combination of valid interrupt flags for the I2C module (I2C_IF_nnn).

Definition at line 299 of file em_i2c.h .

Referenced by I2C_Init() , I2C_Reset() , I2C_Transfer() , and I2C_TransferInit() .

Disable one or more I2C interrupts.

Parameters

[in]	i2c	Pointer to I2C peripheral register block.
[in]	flags	I2C interrupt sources to disable. Use a bitwise logic OR combination of valid interrupt flags for the I2C module (I2C_IF_nnn).

Definition at line 319 of file em_i2c.h .

Enable one or more I2C interrupts.

Note

Depending on the use, a pending interrupt may already be set prior to enabling the interrupt. To ignore a pending interrupt, consider using I2C_IntClear() prior to enabling the interrupt.

Parameters

[in]	i2c	Pointer to I2C peripheral register block.
[in]	flags	I2C interrupt sources to enable. Use a bitwise logic OR combination of valid interrupt flags for the I2C module (I2C_IF_nnn).

Definition at line 344 of file em_i2c.h .

Get pending I2C interrupt flags.

Note

Event bits are not cleared by the use of this function.

Parameters

[in]

i2c

Pointer to I2C peripheral register block.

Returns

I2C interrupt sources pending. A bitwise logic OR combination of valid interrupt flags for the I2C module (I2C_IF_nnn).

Definition at line 367 of file em_i2c.h .

Get enabled and pending I2C interrupt flags. Useful for handling more interrupt sources in the same interrupt handler.

Note

Interrupt flags are not cleared by the use of this function.

Parameters

[in]

i2c

Pointer to I2C peripheral register block.

Returns

Pending and enabled I2C interrupt sources Return value is the bitwise AND of

• the enabled interrupt sources in I2Cn_IEN and
• the pending interrupt flags I2Cn_IF

Definition at line 389 of file em_i2c.h .

Set one or more pending I2C interrupts from SW.

Parameters

[in]	i2c	Pointer to I2C peripheral register block.
[in]	flags	I2C interrupt sources to set to pending. Use a bitwise logic OR combination of valid interrupt flags for the I2C module (I2C_IF_nnn).

Definition at line 408 of file em_i2c.h .

Reset I2C to the same state that it was in after a hardware reset.

Note

The ROUTE register is NOT reset by this function to allow for centralized setup of this feature.

Parameters

[in]

i2c

A pointer to the I2C peripheral register block.

Definition at line 449 of file em_i2c.c .

References I2C_IntClear() .

Get slave address used for I2C peripheral (when operating in slave mode).

For 10-bit addressing mode, the address is split in two bytes, and only the first byte setting is fetched, effectively only controlling the 2 most significant bits of the 10-bit address. Full handling of 10-bit addressing in slave mode requires additional SW handling.

Parameters

[in]

i2c

Pointer to I2C peripheral register block.

Returns

I2C slave address in use. The 7 most significant bits define the actual address, the least significant bit is reserved and always returned as 0.

Definition at line 436 of file em_i2c.h .

Get slave address mask used for I2C peripheral (when operating in slave mode).

The address mask defines how the comparator works. A bit position with value 0 means that the corresponding slave address bit is ignored during comparison (don't care). A bit position with value 1 means that the corresponding slave address bit must match.

For 10-bit addressing mode, the address is split in two bytes, and only the mask for the first address byte is fetched, effectively only controlling the 2 most significant bits of the 10-bit address.

Parameters

[in]

i2c

Pointer to I2C peripheral register block.

Returns

I2C slave address mask in use. The 7 most significant bits define the actual address mask, the least significant bit is reserved and always returned as 0.

Definition at line 486 of file em_i2c.h .

Set slave address mask used for I2C peripheral (when operating in slave mode).

The address mask defines how the comparator works. A bit position with value 0 means that the corresponding slave address bit is ignored during comparison (don't care). A bit position with value 1 means that the corresponding slave address bit must match.

For 10-bit addressing mode, the address is split in two bytes, and only the mask for the first address byte is set, effectively only controlling the 2 most significant bits of the 10-bit address.

Parameters

[in]	i2c	Pointer to I2C peripheral register block.
[in]	mask	I2C slave address mask to use. The 7 most significant bits define the actual address mask, the least significant bit is reserved and should be 0.

Definition at line 514 of file em_i2c.h .

Set slave address to use for I2C peripheral (when operating in slave mode).

For 10- bit addressing mode, the address is split in two bytes, and only the first byte is set, effectively only controlling the 2 most significant bits of the 10-bit address. Full handling of 10-bit addressing in slave mode requires additional SW handling.

Parameters

[in]	i2c	Pointer to I2C peripheral register block.
[in]	addr	I2C slave address to use. The 7 most significant bits define the actual address, the least significant bit is reserved and always set to 0.

Definition at line 458 of file em_i2c.h .

Continue an initiated I2C transfer (single master mode only).

This function is used repeatedly after a I2C_TransferInit() to complete a transfer. It may be used in polled mode as the below example shows:

It may also be used in interrupt driven mode, where this function is invoked from the interrupt handler. Notice that, if used in interrupt mode, NVIC interrupts must be configured and enabled for the I2C bus used. I2C peripheral specific interrupts are managed by this software.

Note

Only single master mode is supported.

Parameters

[in]

i2c

A pointer to the I2C peripheral register block.

Returns

Returns status for an ongoing transfer.

• i2cTransferInProgress - indicates that transfer not finished.
• i2cTransferDone - transfer completed successfully.
• otherwise some sort of error has occurred.

Definition at line 504 of file em_i2c.c .

References I2C_TransferSeq_TypeDef::addr , I2C_TransferSeq_TypeDef::buf , I2C_TransferSeq_TypeDef::data , I2C_TransferSeq_TypeDef::flags , I2C_FLAG_10BIT_ADDR , I2C_FLAG_READ , I2C_FLAG_WRITE , I2C_FLAG_WRITE_READ , I2C_IntClear() , i2cTransferArbLost , i2cTransferBusErr , i2cTransferDone , i2cTransferInProgress , i2cTransferNack , i2cTransferSwFault , i2cTransferUsageFault , and I2C_TransferSeq_TypeDef::len .

Referenced by I2C_TransferInit() , and I2CSPM_Transfer() .

Prepare and start an I2C transfer (single master mode only).

This function must be invoked to start an I2C transfer sequence. To complete the transfer, I2C_Transfer() must be used either in polled mode or by adding a small driver wrapper using interrupts.

Note

Only single master mode is supported.

Parameters

[in]	i2c	A pointer to the I2C peripheral register block.
[in]	seq	A pointer to the sequence structure defining the I2C transfer to take place. The referenced structure must exist until the transfer has fully completed.

Returns

Returns the status for an ongoing transfer:

• i2cTransferInProgress - indicates that the transfer is not finished.
• Otherwise, an error has occurred.

Definition at line 838 of file em_i2c.c .

References I2C_TransferSeq_TypeDef::buf , I2C_TransferSeq_TypeDef::flags , I2C_FLAG_READ , I2C_FLAG_WRITE_READ , I2C_IntClear() , I2C_Transfer() , i2cTransferInProgress , i2cTransferUsageFault , and I2C_TransferSeq_TypeDef::len .

Referenced by I2CSPM_Transfer() .