This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

How to clock SysTick from external 32KHz crystal?

I am using an MCB1700 board with a LPC1768.

I am trying to clock the SysTick counter from the external 32KHz crystal which is present on this board and can not get it working.

Did the following:

Cleared the CLKSOURCE bit in the SysTick control register (set for external source)

Configured pin P3.26 to be used as the external clock source as follows:

LPC_PINCON->PINSEL7 |= (0x00000001 << 20);

According the documentation, setting bit 21:20 of PINSEL7 configures P3.26 as STCLK

Tried all combinations of the two bits (21:20)in PINMODE7 register and bit26 in the PINMODE_OD3 register.

No luck, no combination makes SysTick count.

What am I doing wrong, any suggestion is very welcome.

Leon

0