The QG family introduces the ICS module to the S08 family. This is a highly accurate, low power internal clock source. With the ICS and XOSC, the customer has the option to either eliminate external components such as a crystal and use the internal clock source to save money and board space, or drive the clock from an external source. The low power oscillator with an accurate 32kHz crystal is a viable choice for applications that require time to be kept. The MAXs for the ICS, when trimmed, are 0.2% resolution and +/-2% deviation across voltage and temperature, but as you can see, the typicals (samples are taken across volt and temp) are more accurate. The ICS limits the max bus speed of the device to 10MHz vs the GB/GT ICG, which offers up to 20MHz. The tradeoffs for this performance are better run currents, accuracy, and die size.