TMS320C6678 - Advisory 8 Multiple PLLs May Not Lock After Power-on Reset Issue

Erez,

Yes, because of the PLL lock issue, you must first boot using I2C or SPI to implement the workaround.  Once you have done that, you can write the DEVSTAT register to reflect the desired boot mode, then write the re-enter address to  the boot ROM and boot via the desired method. This is essentially what we have done on the EVMs.  Here are the steps used by the EVM:

1) FPGA samples the bootmode pins

2) FPGA forces the DSP to boot via I2C for the fix

3) PLL is intiated correctly with the IBL code on the I2C.

4) IBL reads the sampled bootmode from a FPGA register and writes this value into the DEVSTAT register

5) IBL writes the Boot ROM enter address into the DSP PC

6) DSP executes the desired internal ROM boot mode as normal

If you want to look at the source for this work around, you can find it in the MCSDK: http://software-dl.ti.com/sdoemb/sdoemb_public_sw/bios_mcsdk/02_00_00_06/index_FDS.html

Once installed, look at:  C:\Program Files\Texas Instruments\mcsdk_2_00_00_beta1\tools\boot_loader\ibl\src\device\c661x\c661xinit.c and C:\Program Files\Texas Instruments\mcsdk_2_00_00_beta1\tools\boot_loader\ibl\src\main\iblinit.c.  Look at the iblEnterRom and devicePllConfig functions.

Hope that helps,

Travis

Hi Nuoxi,

As Travis mentioned, if you have C6678 rev1.0, then you need to do the PLL fix. The example for PLL fix without using IBL is in the processors wiki page. The link is below. This example is traditionally for I2C boot, but you can change it based on the SPI boot example you have to get them in SPI boot format. This will set the PLL to the correct configuration and re-enters the boot that you need.

http://processors.wiki.ti.com/images/4/4d/SecondaryBoot_PLLfix.zip

Thanks,

Arun.