[F2812 EZDSP] Inaccurate timing executing code relocated from Flash | TMS320C28x

Hi Expers I am now using the eZdsp board to perform some tasks on the GPIO of TMS320f2812 dsp controller, 150 mhz. PROBLEM SCNENARIO: =================== 1. When i run from JTAG emulator (execute completely in RAM), i am able to control the output timing of GPIO pin very accurately by 6.7ns per NOP operation (1 isntruction). This means i can get the 150 Mhz as state by the. HOWEVER, when i burn my code into the flash using the flash programmer tool in CCS v2, i can't get exactly the same 6.7ns per cycle. I have copied the code from flash to HO SARAM, as below: //****in my C file.. #pragma CODE_SECTION(dataMgmt,"ramfuncs"); ... MemCopy(&RamfuncsLoadStart, &RamfuncsLoadEnd, &RamfuncsRunStart); ... //****in the linker.cmd file, ramfuncs : LOAD = FLASHA, RUN = RAMH0, LOAD_START(_RamfuncsLoadStart), LOAD_END(_RamfuncsLoadEnd), RUN_START(_RamfuncsRunStart), PAGE = 0 What i get now is that.. i can only get 8.3ns per NOP operation, which is only roughly 120 MIPS. I understand that running from flash will be slow, but i have already copied the code from flash to HO SARAM. I have confirmed this by checking the linker output map file.. // the linker output MAP file... 0x3f66xx is still in flash, 0x3f80000 is beginning of dsp internal RAM 003f664b _RamfuncsLoadStart 003f685e _RamfuncsLoadEnd 003f685e _PieVectTableInit 003f7ff8 _CsmPwl 003f8000 _RamfuncsRunStart 003f8000 _InitFlash 003f8016 _pieCDelay 003f801d _dataMgmt FYI, i have enabled the flash pipelining mode, and also enable the PLL.. //enable flash pipeline mode FlashRegs.FOPT.bit.ENPIPE=1; //xclkout, sysclkout initialization SysCtrlRegs.PLLCR.all=0xa; XintfRegs.XINTCNF2.bit.XTIMCLK=0x0; //if xtimclk=0, xtimclk=sysclk/1 XintfRegs.XINTCNF2.bit.CLKMODE=0x0; //if clkmode=0, xclkout NOT divide QUESTIONS: =========== 1. Is my way of relocating the code wrong?? 2. What can possibly cause this? Is it what it's supposed to be? why i can get the exact timing in jtag emulation mode, but not running from flash even though i have relocated the code? 3. BTW, is there any other easier way to relocate code? I want to relocate the whole section, for eg. the .cinit, .text, .pinit or etc. straight away to RAM, rather than relocating function by function by using #pragma Really really Thanks

(You need to be a member of c28x -- send a blank email to c28x-subscribe@yahoogroups.com )

Sign in

Search c28x

Subscribe to c28x

Sponsor

Discussion Groups

Discussion Groups | TMS320C28x | [F2812 EZDSP] Inaccurate timing executing code relocated from Flash

[F2812 EZDSP] Inaccurate timing executing code relocated from Flash - seankuay - Jan 9 3:47:00 2006