Hello everybody,
I'm having some trouble with my MSP430F1132.
I am initializing my Basic clock module with the following and have a 4MHz
crystal attached. My MSP430 is running from JTAG power at 2.5V.
#define BCSCTL1_INIT XTS
#define BCSCTL2_INIT SELM0|SELM1|SELS
BCSCTL1 = BCSCTL1_INIT;
BCSCTL2 = BCSCTL2_INIT;
When I set P1.4 to its peripheral mode I get SMCLK out and I see 4Mhz on my
scope at that pin. When I instruct the MSP430 to toggle P1.0 I get an on
period of 40uS. It takes 3 cycles to toggle the bit so that period should
correspond to 3 CPU cycles or 1 cycle of 13uS. This yields a frequency of
75KHz. Clearly if my SMCLK and my MCLK are clocked from the same source
the two calculated frequencies should be consistent. I have also used two
different F1132s in the same circuit with no difference.
Additionally I have a timer interrupt configured to happen every mS which
gets successfully executed at the proper frequency.
If for some reason my instructions are being executed at 75kHz I have a
big problem. Does any one know whats up?
Below is the code for my bit toggle loop.
while (1) {
P1OUT = 0x03;
e0b6: f2 40 03 00 mov.b #3, &0x0021 ;#0x0003
e0ba: 21 00
P1OUT = 0x00;
e0bc: c2 43 21 00 mov.b #0, &0x0021 ;r3 As==00
e0c0: fa 3f jmp $-10 ;abs 0xe0b6
}
