TM4C1294NCPDT: What is missing in my I2C init?

David Chance

Part Number: TM4C1294NCPDT

I am using TM4C1294's I2C module 2, I picked some samples online, but it drops dead at I2CMasterInitExpClk, can anyone give me pointer or a working example? Thanks!

_______________________________

ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
SYSCTL_OSC_MAIN |
SYSCTL_USE_PLL |
SYSCTL_CFG_VCO_480), 120000000);

SysCtlDelay(100);

SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C2);
SysCtlPeripheralReset(SYSCTL_PERIPH_I2C2);

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPION);
GPIOPinConfigure(GPIO_PN5_I2C2SCL);
GPIOPinConfigure(GPIO_PN4_I2C2SDA);

GPIOPinTypeI2C(GPIO_PORTN_BASE,GPIO_PIN_4); // Configures SDA
GPIOPinTypeI2CSCL(GPIO_PORTN_BASE, GPIO_PIN_5); // Configures SCL

I2CMasterInitExpClk(I2C2_BASE, SysCtlClockGet(), false);

over 6 years ago

0 Bob Crosby over 6 years ago

TI__Guru 72500 points

The function "SysCtlClockGet()" is not to be used with the TM4C129x devices. Instead you should pass the variable ui32SysClock which was set by your call to SysCtlClockFreqSet().

0 David Chance over 6 years ago in reply to Bob Crosby

Genius 4775 points

Changed to ui32SysClock, and the result is the same

0 Bob Crosby over 6 years ago in reply to David Chance

TI__Guru 72500 points

Here is a working example of using I2C0 as a master and connecting it to I2C2 used as a slave. You must connect the SDA and SCL pins and provide external pull-up resistors.

/cfs-file/__key/communityserver-discussions-components-files/908/5355.I2C0MtoI2C2S.zip

0 David Chance over 6 years ago in reply to Bob Crosby

Genius 4775 points

I tried your example, it works fine

Since I use a different pin for I2C module 2, so I need to change from

GPIOPinConfigure(GPIO_PL1_I2C2SCL);
GPIOPinConfigure(GPIO_PL0_I2C2SDA);
GPIOPinTypeI2CSCL(GPIO_PORTL_BASE, GPIO_PIN_1);
GPIOPinTypeI2C(GPIO_PORTL_BASE, GPIO_PIN_0);

to:

GPIOPinConfigure(GPIO_PN5_I2C2SCL);
GPIOPinConfigure(GPIO_PN4_I2C2SDA);
GPIOPinTypeI2CSCL(GPIO_PORTN_BASE, GPIO_PIN_5); // Configures SCL
GPIOPinTypeI2C(GPIO_PORTN_BASE,GPIO_PIN_4); // Configures SDA

Now the program locks up at the same spot

I read TM4C1294's manual again (www.ti.com/.../tm4c1294ncpdt.pdf), page 1277, table 18-1, and I don't see any problem to swap these two pins.

Can you take another look? Thanks!

0 Bob Crosby over 6 years ago in reply to David Chance

TI__Guru 72500 points

Did you change:

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOL);

    /* to */

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPION);

0 David Chance over 6 years ago in reply to Bob Crosby

Genius 4775 points

You got me! Thanks!

0 ASHWINEE JADHAO over 6 years ago in reply to Bob Crosby

Expert 1010 points

WHICH IS THIS DOCUMENT , WILL YOU SEND THE LINK

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TM4C1294NCPDT: What is missing in my I2C init?