Clock Frequencies and Calculations
The frequency of the microcontroller's internal crystal is roughly 32KHz. After running the debugger mode and searching through the ICGC1 and ICGC2 (internal clock generator) registers, we found the settings for the GB60's frequency output to be 37.7MHz. The BUSCLK frequency can be found by dividing by two.
Calculations: Ficgout = (Fext)*P*(N/R); where Fext = 32,000
Looking at the ICG control registers (memory map is 0048 in debugger),the following set values were found: P = 64, N = 18, R = 1.
Ficgout = (32,000)*(64)*(18/1) = 37,748,736;
BUSCLK = (Ficgout)/2 = (37.7 MHz)/2 = 18.85 MHz;
For the microcontroller, the BUSCLK frequency = 18 MHz
Note: For the serial communications port (Port C), we are stuck between two settings in frequency that center our goal frequency of 115 KHz: 104 KHz and 119 KHz. Given that the router cannot handle anything greater than 115 KHz, we have to use 104 KHz at the moment. This is still being worked out with the interfacing crew.
Update
The baud rate is set to 9600 bits per second. We are not using 115KHz or 104KHz any more. After testing, the microcontroller communicated best at this rate with the router.
We will be reverting back to 104KBaud once we are done testing. This way a serial monitor can be used. Please see afterburn's blog for more info.
