topic Re: MPC5748G_I2C module in MPC5xxx

MPC5748G_I2C module

huqiang — Wed, 27 Apr 2016 01:44:09 GMT

When I initial the I2C module, I run the program step by step, observe the I2C registers.

I notice that the "I2C_2.IBCR.B.MSSL" bit is always 0 and "I2C_2.IBDR.R" is also always 0.

When I run the code "I2C_2.IBCR.B.MSSL = 1;", why will bit "I2C_2.IBSR.B.IBIF" and "I2C_2.IBSR.B.IBAL" turn to 1? instead of bit ""I2C_2.IBCR.B.MSSL" turn to 1?

Is it that I cannnot select master mode, so I cannot set the "I2C_2.IBDR.R"?

void I2C_2_Init(void)

{

// I2C Bus Frequency Divider Register (I2C_IBFD)

I2C_2.IBFD.B.IBC = 0x20; // Division ratio to obtain SCL frequency from Platform clock/2.

// I2C Bus Control Register (I2C_IBCR)

I2C_2.IBCR.B.MDIS = 0; // Enable I2C module

I2C_2.IBCR.B.IBIE = 1; // Interrupts from the I2C Bus module are enabled

I2C_2.IBCR.B.TXRX = 1; // Transmit Mode

// Start I2C master mode transmit

I2C_2.IBCR.B.MSSL = 1; // Master Mode - When this bit is changed from 0 to 1, a START signal is generated on the bus and the master mode is selected

I2C_2.IBSR.B.IBIF = 0; // I-Bus Interrupt Flag

I2C_2.IBDR.R = 0x55; // Sent out 0x55

// Observe changes in IBSR[TCF]

// while (I2C_0.IBSR.B.TCF == 0);

//Wait until IBSR[IBIF] = 1.

while(I2C_2.IBSR.B.IBIF == 0);

I2C_2.IBCR.B.MSSL = 0; // Generate stop signal;

}

Original Attachment has been moved to: I2C_Z4_1.zip

Re: MPC5748G_I2C module

petervlna — Thu, 28 Apr 2016 08:42:40 GMT

Hi,

Seems to me that you can use only I2C_0 as master.

Peter

Re: MPC5748G_I2C module

huqiang — Thu, 28 Apr 2016 14:04:20 GMT

Thank you. I've tried to use I2C_0 as master, it worked successfully.

Can I use other I2C_x as master? How to code?

Re: MPC5748G_I2C module

PetrS — Fri, 29 Apr 2016 11:45:51 GMT

All I2C modules can work as master. You have to configure pads properly.

Both pins, SDA and SCL, must be configured to enable output buffer, select open-drain function, enable input buffer, select intenal pull ups if there are no external one.

This config can be used:

SIUL2.MSCR[73].R = 0x23880002; //PE[9] - I2C_2 SCL

SIUL2.IMCR[781-512].R = 1;

SIUL2.MSCR[72].R = 0x23880004; //PE[8] - I2C_2 SDA

SIUL2.IMCR[782-512].R = 1;

BR, Petr

Re: MPC5748G_I2C module

huqiang — Thu, 05 May 2016 02:28:46 GMT

Petr,

Thanks a lot.

Do you have some I2C module examples of transfering data?

BR, Qiang