SSi max speed in TM4C123

Hello Dhanush

The SSI Clock is bounded by the following equation

SSInClk = SysClk / (CPSDVSR * (1 + SCR))

If the SSInCLK is not achievable then it will go to the first value below it. In case of 80MHz system clock the values possible by this equation are 40MHz, 20MHz and so on. Since 40 is greater than 33 the next available is 20 which is why you see 20MHz on the SSICLK pin

Regards

Amit

Amit,

What should i do to configure SSI at 40MHz.

Thanks and regards

Dhanush

Hello Dhanush,

Change the Baud Rate from 33000000 to 40000000

SSIConfigSetExpClk(SSI0_BASE, SysCtlClockGet(), SSI_FRF_MOTO_MODE_3,SSI_MODE_MASTER,  40000000, 8)

Regards

Amit

Amit Ashara said:

Hello Dhanush,

Change the Baud Rate from 33000000 to 40000000

SSIConfigSetExpClk(SSI0_BASE, SysCtlClockGet(), SSI_FRF_MOTO_MODE_3,SSI_MODE_MASTER,  40000000, 8)

Regards

Amit

hello amit ,

That is the actual problem i am facing  , I configured  contoler  with 80MHz freq

       SysCtlClockSet(SYSCTL_SYSDIV_2_5  | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ);;     

       I configured SSI at 40MHz

      SSIConfigSetExpClk(SSI0_BASE, SysCtlClockGet(), SSI_FRF_MOTO_MODE_3,SSI_MODE_MASTER,  40000000, 8);

      SSI is NOT WORKING  .In this case SSI  work only at 20MHz (max) .

I want to configure controller at 80MHz and SSi at 40MHz.

Thannks & regards,

Dhanush

Hello Dhanush,

In the TIVAWare 2.1.0 there is an issue with SysCtlClockGet which causes the system frequency return value to be 66MHz. Instead of using the function, I recommend using the value 80000000

Regards

Amit

Amit Ashara said:

In the TIVAWare 2.1.0 there is an issue with SysCtlClockGet which causes the system frequency return value to be 66MHz. Instead of using the function, I recommend using the value 80000000

hello amit,

    I am not using TIVAWare 2.1.0 , i am using TIVAWare 2.0. . I have already cross checked SysCtlClockGet() function and it is giving an correct value as 80000000,so what you are telling is not an issue.

Please tell me is there an any issue with is new TIVA controller.

Thanks and regards,

Dhanush

Hello Dhanush,

Can you reset the peripheral before enabling the clock to SSI and then try? If this does not help then I would ask you to send in your ccs project

Regards

Amit

Amit Ashara said:

Can you reset the peripheral before enabling the clock to SSI and then try? If this does not help then I would ask you to send in your ccs project

Dear Amit,

 I have tried it,but not working.  Please give me your email id to send my CCS project. My email id is

dhanush.nair@arucomelectronics.com

Thanks & regards,

Dhanush

Hello Dhanush

You can zip the CCS project and attach it to the E2E post

Regards

Amit

Hello amit,

 Please find attachent,

1261.memory.rar

  I also have one more issue.I am using TMS320XDS100 V2 (OLIMEX) for programming my TIVA controller using USB-JTAG. But till now I am not  able to use the programmer.There seems to be no documentation about the programmer.I have heard that you have also used the same kit.

Please help.

Thanks & regards,

Dhanush

Hello Dhanush

I ran the test code and the SSI gives 40MHz as SSI Clock on PA2 Pin

Regards

Amit

Dhanush Nair said:

I also have one more issue.I am using TMS320XDS100 V2 (OLIMEX) for programming my TIVA controller using USB-JTAG. But till now I am not  able to use the programmer.There seems to be no documentation about the programmer.I have heard that you have also used the same kit.

Please help.

Plz also suggest some solution for this query

Regards

Dhanush

Hello Dhanush,

The Olimex TMS320XDS100V2 used a 14-pin TI JTAG or a 20-pin TI JTAG. The connection for JTAG on this is different from a 20-Pin ARM JTAG. The following link will help connecting the correct signals.

http://processors.wiki.ti.com/index.php/XDS_Target_Connection_Guide#Table_8._Emulation_Header_Pin_Definition

Regards

Amit