What are the best terms for crystals/resonators/oscillators used with microcontrollers that cover each of the following groups:

• clock sources that require an additional oscillator circuit (NOT gate) of the type found in many microcontrollers, and are therefore hooked up to both CLKIN and CLKOUT pins of a microcontroller
• clock sources that provide a clock signal without additional circuitry, and can therefore be hooked up to a CLKIN pin without requiring additional pins

What are the best terms for crystals/resonators/oscillators used with microcontrollers that cover each of the following groups:

• clock sources that require an additional oscillator circuit (NOT gate) of the type found in many microcontrollers, and are therefore hooked up to both CLKIN and CLKOUT pins of a microcontroller
• clock sources that provide a clock signal without additional circuitry, and can therefore be hooked up to a single pin on the device (typically CLKIN or OSCIN) without requiring additional pins