[time-nuts] Rb Oscillator - rather fundamental question

Chris Kuethe chris.kuethe at gmail.com
Tue Feb 23 22:26:48 UTC 2010

On Tue, Feb 23, 2010 at 2:10 PM, Matthew Smith <matt at smiffytech.com> wrote:
> BTW: does anyone know if a 0.55V p-t-p sine wave from an Rb source would
> be enough to clock an Atmel AVR microcontroller?  The crystal/clock
> input *is* an amplifier, but didn't know if I'd need to do anything to
> the signal first, to get it closer to the 5V logic level.

AVR's define 0.8*Vcc as V[IH1] and 0.1*Vcc as V[IL1], and you can get
AVR's rated down to 1.8V. Your 0.55V signal won't work.

Source: page 316 and 322 of the ATmega48/88/168/328 datasheet
(http://atmel.com/dyn/resources/prod_documents/8271.pdf), likely any
other AVR will have these requirements.

GDB has a 'break' feature; why doesn't it have 'fix' too?

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