msp430g2553 frequency

Hi Mohammed!

I don't really understand what you are exactly asking for, but if you want to know how to configure the MSP to run at 16MHz (maximum allowed for guaranteed faultless operation), you can use the calibration constants that are saved in the device - simply add these two lines:

BCSCTL1 = CALBC1_16MHZ; // Set range
DCOCTL  = CALDCO_16MHZ; // Set DCO step and modulation

Make sure the device is powered with 3.3V since this voltage is required for that frequency:

Dennis

MOHAMMAD NASEER M N said:

can we get more than 16Mz frequency from g2553 kit

The device might work with higher frequencies, but TI does not guarantee for proper operation in that case - I don't know the maximum frequency you can achieve with the DCO, but you can give it a try by using the maximum settings. According to the datasheet, a fed in external clock source has a maximum of 50kHz, but this might also work with higher values - if it extends the 16MHz internal clock...no idea - never tested.

MOHAMMAD NASEER M N said:

i want to take a signal from g2553 kit through a pin(header connection) of g2553 of 16mhz and i wanna see in CRO through that pin

The MSP430G2553 can output SMCLK at P1.4:

If no divider for SMCLK is used, SMCLK is equal to MCLK - to output it, simply enable the special function for P1.4 by writing:

P1DIR  |=  0x10; // P1.4 to output direction
P1SEL  |=  0x10; // P1.4 selection register 1 set
P1SEL2 &= ~0x10; // P1.4 selection register 2 cleared (can be omitted, is 0 after start)

If you now connect an oscilloscope to P1.4, you can measure your system clock.

Dennis

Or, try this.

#include <msp430.h>
void main(void)
{
  P1SEL = 0x10;
  P1DIR = 0x10;
  BCSCTL2 = 0x30;
  BCSCTL1 = 0x8F;
  DCOCTL = 0xFF;
  while (1);
}

What frequency do you see at P1.4? Do not worry, the CPU is running at 1/8 of that frequency, well within its capability.