Msp430 External Clock Source

The msp430 clock module can have up to four clock sources.

Msp430 external clock source.

From ultra low power low cost on chip clock sources to high speed external crystal inputs. All of these can be brought to bear through the use of 3 internal clock signals which drive the cpu along as well as fast and slow peripherals. Clock sources can be internal or external. The main signals in the msp430 include.

I have seen the msp430 seems to have very fast wake up time from deep sleep in the order of us i have not been able to ascertain if this is only when running the dco as the source of cpu clock or if it is applicable also when the cpu clock source is an external crystal. So the clock source is a ttl level square wave signal. You current code afects both in case of xt1 switch it to hf operation the drive strength can be set to minimum. For the purposes of these tutorials using the internal oscillator shall be sufficient.

Figure 1 shows the inputs and outputs of the programmable clock source. External oscillators are usually more accurate but they add to cost and space on the board. Programmable clock source inputs outputs after a device reset the msp430 mcu sources the subsystem master clock smclk from the dco configured to run at 16 mhz. The default value is 05h 0000 0101.

Aclk is divided by 1 2. This exercise has been divided into 4 sub sections. Observe the bcsctl register configuration steps to understand clock configuration. External programmable watchdog timer using msp430 mcus figure 2.

The reset value is 0000 0000. The clock tree in the msp430 is actually composed of several signals whose source is selectable. The source of mclk and smclk are selected. This flexibility helps power cpu and peripherals using different clocks to achieve either speed or low power.

Internal digitally controller oscillator. This register is used to configure external crystal lfxt1 or xt2 second external crystal. The device then executes. External watchdog timer software flow chart to run the demo on a pc connect the launchpad kit or target development board to the pc load the code.

These subsections deal with configuring the clock to be sourced from different options available on msp430. High accuracy external 32 768 khz crystal for best performance. The meaning is that i want to use 8mhz clock from external clock source. The description at the beginning of the sub section gives the intended clock source.

The external wdt has a separate clock source providing redundancy and making the system more robust. And then follow the loop procedure. In this case set the bypass bit do you want to use xt1 or xt2.