TFT LCD Panel - Changing System Clock Frequency

Frozen Content

The NB2DSK01 motherboard provides an on-board system clock generator in the form of the SPI-compatible ICS307-02 device. The frequency of the programmable clock output from this device can be changed directly through the GUI.

To access clock frequency-related controls (Figure 1), from the Home screen of the GUI touch the icon, followed by the icon.


Figure 1. Controls to change the frequency of the
motherboard's programmable system clock.

Simply touch the frequency required – the supported frequencies in the range 6 to 200MHz are listed – and then touch the icon to commit your selection.

The requested clock frequency is written, over the SPI bus, to the ICS307-02 device. It is also stored in the motherboard's common-bus Flash memory. The new frequency is read back from the Flash memory and reflected at the top-center of the panel display.

As the frequency is stored in Flash memory, it is persistent across design and hardware sessions. Cycling the NB2DSK01's power for example will result in the last set clock frequency, stored in the Flash memory, to be used at startup - regardless of whether that frequency was set by the firmware (through the GUI) or by Altium Designer.

The user-programmable clock has a default frequency of 50MHz.
 

Only the predefined frequencies for the programmable clock, based on the 20MHz fixed reference clock frequency, are available for selection. Should you wish a different frequency between 6 and 200MHz, this can be achieved via the Instrument Rack – NanoBoard Controllers panel, from within Altium Designer. Access this panel by double-clicking on the icon for the NB2DSK01, in the NanoBoard chain of the Devices view (View » Devices View).

 

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