I'm using BF518f - EZBoard.
My application is based on battery supply. Because of that, I would like to operate on the lowest possible Core Clk (and System Clk). of course i also controlled Vddint down to 1.164 (the minimum).
I bypassed the PLL thus - Clkin = Cclk = Sclk = 25 MHz.
I only found maximum specificaions for the frequency - is there also a minimum?
appart from the fact that the application is slower - are there any major drawbacks in using a low freq?
Are there any ajdustments i need to do in the code regarding the peripherals on the EZBoard when changing the frequency/Vddint? i mean update the code (codec / uart communication etc.)
There are minimum clock frequencies described in the ADSP-BF512/ADSP-BF514/ADSP-BF516/ADSP-BF518(F) Blackfin Embedded Processor Data Sheet . The EZ-Kit has a 25MHz input clock, so if you stick with that then your only limitation is the minimum VCO frequency of 70MHz. This only applies when the PLL is not bypassed. The VCO is calculated by multiplying CLKIN times MSEL. This number is the divided by two if the DF bit is set.
If you want to change the CLKIN on the EZ-Kit or build a custom board with a different crystal/osciallator, you are limited to a minimum CLKIN frequency of 12MHz if you have silicon revision 0.2 or 14MHz if you have silicon revisions 0.0 or 0.1 due to anomaly 05000472 described in ADSP-BF512/BF514/BF516/BF518(F) Blackfin Anomaly List for Revisions 0.0, 0.1 (Rev E, 01-26-2010) .