I2CEMLIB

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 I2C_Transfer() , I2C_TransferInit() , performI2CTransfer() , 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() , EEPROM_AckPoll() , I2C_Transfer() , SI1133_registerBlockWrite() , SI1133_registerWrite() , Si1147_Write_Block_Register() , Si1147_Write_Register() , 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() , Si7013_Detect() , Si7013_GetFirmwareRevision() , SI7021_cmdRead() , SI7210_registerRead() , Si72xx_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() , and SI7210_registerWrite() .

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 .

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, the max value is somewhat reduced.

Definition at line 80 of file em_i2c.h .

Suggested default config for I2C init structure.

Definition at line 219 of file em_i2c.h .

Referenced by setupI2C() .

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 current configured I2C bus frequency.

This frequency is only of relevance when acting as master.

Parameters

[in]

i2c

Pointer to I2C peripheral register block.

Returns

Current I2C frequency in Hz.

Definition at line 172 of file em_i2c.c .

References _I2C_CTRL_CLHR_MASK , _I2C_CTRL_CLHR_SHIFT , I2C_TypeDef::CLKDIV , CMU_ClockFreqGet() , cmuClock_HFPER , and I2C_TypeDef::CTRL .

Set I2C bus frequency.

The bus frequency is only of relevance when acting as a master. The bus frequency should not be set higher than the max frequency accepted by the slowest device on the bus.

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

Please refer to the reference manual, details on I2C clock generation, for max allowed theoretical frequencies for different modes.

Parameters

[in]	i2c	Pointer to I2C peripheral register block.
[in]	freqRef	I2C reference clock frequency in Hz that will be used. If set to 0, then HFPER clock is used. Setting it to a higher than actual configured value only has the consequence of reducing the real I2C frequency.
[in]	freqScl	Bus frequency to set (actual bus speed may be lower due to integer prescaling). Safe (according to I2C specification) max frequencies for standard, fast and fast+ modes are available using I2C_FREQ_ defines. (Using I2C_FREQ_ defines requires corresponding setting of type .) Slowest slave device on bus must always be considered.
[in]	i2cMode	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 higher bus clock in fast and fast+ modes.

Definition at line 224 of file em_i2c.c .

References _I2C_CLKDIV_DIV_MASK , _I2C_CTRL_CLHR_MASK , _I2C_CTRL_CLHR_SHIFT , BUS_RegMaskedWrite() , I2C_TypeDef::CLKDIV , CMU_ClockFreqGet() , cmuClock_HFPER , I2C_TypeDef::CTRL , I2C_CTRL_SLAVE , 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	Pointer to I2C peripheral register block.
[in]	enable	true to enable counting, false to disable.

Definition at line 329 of file em_i2c.c .

References _I2C_CTRL_EN_SHIFT , BUS_RegBitWrite() , and I2C_TypeDef::CTRL .

Initialize I2C.

Parameters

[in]	i2c	Pointer to I2C peripheral register block.
[in]	init	Pointer to I2C initialization structure.

Definition at line 346 of file em_i2c.c .

References _I2C_CTRL_EN_SHIFT , _I2C_CTRL_SLAVE_SHIFT , _I2C_IFC_MASK , BUS_RegBitWrite() , I2C_Init_TypeDef::clhr , I2C_TypeDef::CTRL , I2C_Init_TypeDef::enable , I2C_Init_TypeDef::freq , I2C_BusFreqSet() , I2C_TypeDef::IEN , I2C_TypeDef::IFC , I2C_Init_TypeDef::master , and I2C_Init_TypeDef::refFreq .

Referenced by I2CSPM_Init() , and setupI2C() .

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 bitwse logic OR combination of valid interrupt flags for the I2C module (I2C_IF_nnn).

Definition at line 299 of file em_i2c.h .

References I2C_TypeDef::IFC .

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 315 of file em_i2c.h .

References I2C_TypeDef::IEN .

Enable one or more I2C interrupts.

Note

Depending on the use, a pending interrupt may already be set prior to enabling the interrupt. Consider using I2C_IntClear() prior to enabling if such a pending interrupt should be ignored.

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 336 of file em_i2c.h .

References I2C_TypeDef::IEN .

Get pending I2C interrupt flags.

Note

The 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 355 of file em_i2c.h .

References I2C_TypeDef::IF .

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 The return value is the bitwise AND of

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

Definition at line 377 of file em_i2c.h .

References I2C_TypeDef::IEN , and I2C_TypeDef::IF .

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 396 of file em_i2c.h .

References I2C_TypeDef::IFS .

Reset I2C to same state as after a HW reset.

Note

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

Parameters

[in]

i2c

Pointer to I2C peripheral register block.

Definition at line 372 of file em_i2c.c .

References _I2C_CLKDIV_RESETVALUE , _I2C_CTRL_RESETVALUE , _I2C_IEN_RESETVALUE , _I2C_IFC_MASK , _I2C_SADDR_RESETVALUE , _I2C_SADDRMASK_RESETVALUE , I2C_TypeDef::CLKDIV , I2C_TypeDef::CTRL , I2C_TypeDef::IEN , I2C_TypeDef::IFC , I2C_TypeDef::SADDR , and I2C_TypeDef::SADDRMASK .

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 420 of file em_i2c.h .

References I2C_TypeDef::SADDR .

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 470 of file em_i2c.h .

References I2C_TypeDef::SADDRMASK .

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 498 of file em_i2c.h .

References I2C_TypeDef::SADDRMASK .

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 442 of file em_i2c.h .

References I2C_TypeDef::SADDR .

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

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

* I2C_TransferReturn_TypeDef ret;
*
* // Do a polled transfer
* ret = I2C_TransferInit(I2C0, seq);
* while (ret == i2cTransferInProgress)
* {
*   ret = I2C_Transfer(I2C0);
* }
* 

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 SW.

Note

Only single master mode is supported.

Parameters

[in]

i2c

Pointer to I2C peripheral register block.

Returns

Returns status for ongoing transfer.

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

Definition at line 419 of file em_i2c.c .

References I2C_TransferSeq_TypeDef::addr , I2C_TransferSeq_TypeDef::buf , I2C_TypeDef::CMD , I2C_TransferSeq_TypeDef::data , I2C_TransferSeq_TypeDef::flags , I2C0 , I2C1 , I2C_CMD_ACK , I2C_CMD_NACK , I2C_CMD_START , I2C_CMD_STOP , I2C_FLAG_10BIT_ADDR , I2C_FLAG_READ , I2C_FLAG_WRITE , I2C_FLAG_WRITE_READ , I2C_IF_ACK , I2C_IF_ARBLOST , I2C_IF_BUSERR , I2C_IF_MSTOP , I2C_IF_NACK , I2C_IF_RXDATAV , I2C_IFC_ACK , I2C_IFC_MSTOP , I2C_IFC_NACK , i2cTransferArbLost , i2cTransferBusErr , i2cTransferDone , i2cTransferInProgress , i2cTransferNack , i2cTransferSwFault , i2cTransferUsageFault , I2C_TypeDef::IEN , I2C_TypeDef::IF , I2C_TypeDef::IFC , I2C_TransferSeq_TypeDef::len , I2C_TypeDef::RXDATA , and I2C_TypeDef::TXDATA .

Referenced by I2C_TransferInit() , I2CSPM_Transfer() , and performI2CTransfer() .

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

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

Note

Only single master mode is supported.

Parameters

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

Returns

Returns status for ongoing transfer:

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

Definition at line 747 of file em_i2c.c .

References _I2C_IFC_MASK , I2C_TransferSeq_TypeDef::buf , I2C_TypeDef::CMD , I2C_TransferSeq_TypeDef::flags , I2C0 , I2C1 , I2C_CMD_ABORT , I2C_CMD_CLEARPC , I2C_CMD_CLEARTX , I2C_FLAG_READ , I2C_FLAG_WRITE_READ , I2C_IF_ACK , I2C_IF_MSTOP , I2C_IF_NACK , I2C_IF_RXDATAV , I2C_STATE_BUSY , I2C_Transfer() , i2cTransferInProgress , i2cTransferUsageFault , I2C_TypeDef::IEN , I2C_TypeDef::IF , I2C_TypeDef::IFC , I2C_TransferSeq_TypeDef::len , I2C_TypeDef::RXDATA , and I2C_TypeDef::STATE .

Referenced by I2CSPM_Transfer() , and performI2CTransfer() .