topic Re: LPC82X to be a slave device in LPC Microcontrollers

LPC82X to be a slave device

shujunding — Mon, 08 Aug 2016 03:02:17 GMT

I want to make LPC82X to be a slave device.But when I study the the sample code I download,I Can't unstand the API function "Chip_I2CS_SetSlaveAddr".

The following is sample code:

static void setupI2CSlave(void)

{

/* Some common I2C init was performed in setupI2CMaster(), so it doesn't need to be done again for the slave setup. */

/* Emulated EEPROM 0 is on slave index 0 */

Chip_I2CS_SetSlaveAddr(LPC_I2C_PORT, 0, EEPROM0SLVADD);

/* Disable Qualifier for Slave Address 0 */

Chip_I2CS_SetSlaveQual0(LPC_I2C_PORT, false, 0);

/* Enable Slave Address 0 */

Chip_I2CS_EnableSlaveAddr(LPC_I2C_PORT, 0);

/* Emulated EEPROM 1 is on slave index 1 */

Chip_I2CS_SetSlaveAddr(LPC_I2C_PORT, 1, EEPROM1SLVADD);

/* Enable Slave Address 1 */

Chip_I2CS_EnableSlaveAddr(LPC_I2C_PORT, 1);

/* Clear interrupt status and enable slave interrupts */

Chip_I2CS_ClearStatus(LPC_I2C_PORT, I2C_STAT_SLVDESEL);

Chip_I2C_EnableInt(LPC_I2C_PORT, I2C_INTENSET_SLVPENDING | I2C_INTENSET_SLVDESEL);

/* Enable I2C slave interface */

Chip_I2CS_Enable(LPC_I2C_PORT);

My confusion is that one I2C port can be used as two slave devices?Just only set two different slave addresses?

Original Attachment has been moved to: periph_i2cs_interrupt.zip

Re: LPC82X to be a slave device

kerryzhou — Tue, 09 Aug 2016 06:27:36 GMT

Hi Shujun,

It is the LPC82X I2C feature, this I2C module can support multiple I2C slave addresses.

You can find more details from the LPC82X user manual, page 227.

It can support 4 slave addresses, if you just want to use one slave address, you can just configure one.

The slvNum is define the salve address number in the following API.

/**

* @brief Set a I2C slave address for slave operation

* @param pI2C : Pointer to selected I2C peripheral

* @param slvNum : Possible slave address number, between 0 - 3

* @param slvAddr : Slave Address for the index (7-bits, bit 7 = 0)

* @return Nothing

* @note Setting a slave address also enables the slave address. Do

* not 'pre-shift' the slave address.

STATIC INLINE void Chip_I2CS_SetSlaveAddr(LPC_I2C_T *pI2C, uint8_t slvNum, uint8_t slvAddr)

{

pI2C->SLVADR[slvNum] = (uint32_t) (slvAddr << 1);

}

Wish it helps you!

If you still have question, please let me know!

Have a great day,
Jingjing

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Re: LPC82X to be a slave device

sirdigbychicken — Thu, 24 May 2018 20:43:50 GMT

Hi, I have another question related to Chip_I2CS_SetSlaveAddr

Assuming SetSlaveAddr[0] is for the LPC82x, can SetSlaveAddr[1:3] be linked somehow to I2C2, I2C3 & I2C4 so that an I2C master can talk 'through' the LPC82x to I2C devices connected as slaves to the other 3 I2C ports?

Is that what pI2C is used for?

Thanks,

Mike.

Re: LPC82X to be a slave device

kerryzhou — Tue, 29 May 2018 08:53:30 GMT

Hi Mike,

If you have the question, please create the question post for your own question, please don't follow the old post which is closed.

After you create the question post, we will help you in your own post.

Thanks a lot for your understanding.

Have a great day,
Kerry