clock generation of 9600 from pll

[kask1984]

baudtick

hi every one i want to generate a clock frequency of 9,600 hz (serial communication )
from a frequency of 33.33Mhz using pll
i am using altera cyclone kit
pls help me how can i generate

 

[maheshkuruganti]

You can use an NCO to generate it digitally by using a Accumlator of 32 Bits.
Here is an example

parameter ClkFrequency = 33330000; // 33.33MHz
parameter Baud = 9600;
parameter BaudGeneratorAccWidth = 32;
parameter BaudGeneratorInc = (Baud<<BaudGeneratorAccWidth)/ClkFrequency;

reg [BaudGeneratorAccWidth:0] BaudGeneratorAcc;
always @(posedge clk)
BaudGeneratorAcc <= BaudGeneratorAcc[BaudGeneratorAccWidth-1:0] + BaudGeneratorInc;

wire BaudTick = BaudGeneratorAcc[BaudGeneratorAccWidth];

 

[FvM]

You can use an NCO to generate it digitally

Yes, but an integer frequency divider would do as well, because there's no need to meet the UART baud rate more exactly than 1 or 2 %. An UART receiver would need a multiple of 9600 baud, e.g. *16 for oversampling purposes.

As far as I see, existing UART HDL samples have their baud generator with them, so they simply have to be supplied with a system clock. Examples have been given at edaboard before.