The oscillator circuit for real time and system clock inputs is shown in figure 6-9 and 6-12 in the AM335x datasheet.

The values of components C_{1} and C_{2} referred in the figures depend on the load capacitance (C_{L}) specified by the crystal manufacturer. Load capacitance is calculated as

C_{L} = C_{1}*C_{2}/(C_{1}+C_{2}) + C _{shunt} +C _{pkg} + C _{pcb}

where C _{shunt} is the crystal shunt capacitance also specified by the crystal manufacturer, C _{pkg} and C _{pcb} are the capacitances added due to the interconnections and PCB traces of the design. C _{pkg} and C _{pcb} can be rounded down to 0 -3 pF if the crystal is placed close to the OSD335x and traces are thick enough.

As an example for the 24MHz clock input, let us assume that 7A-24.000MAAJ-T (datasheet) is being used to generate the 24MHz clock signal for OSD335x. The load capacitance on the datasheet is listed as 18pF and the shunt capacitance is listed as 5pF. If we assume C_{1} and C_{2} are of equal capacitance and C_{pkg} + C_{pcb }are 3pF, C_{1} and C_{2} calculated from the above formula come out to be 20pF each.

Similarly for the 32.768Khz clock input, let us assume that ABS07-32.768KHZ-T (datasheet) is being used to generate the 32.768KHz real-time clock. The load capacitance and shunt capacitance on this crystal are listed as 12.5pF and 1.5pF respectively. If we assume C_{1} and C_{2} are of equal capacitance and C_{pkg} + C_{pcb }are 3pF, C_{1} and C_{2} calculated from the above formula come out to be 16pF each.

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