
e2v’s application note interfacing their 1 Gsps 8-bit ADC to AVR. Link here (PDF)
With its smart feature (3-wire serial interface), e2v’s AT84AD001B dual 8-bit 1 Gsps ADC provides you with digital control over various functions offered with the dual ADC: calibration, gain and offset adjustments, DMUX ratio selection, analog and clock input mode, and partial or full standby mode.
This digital control via the 3-wire serial interface can be managed using Atmel’s ATmega128L AVR. The aim of this application note is to provide you with the relevant information for interfacing these two devices.

A little confused by this. Given that the ATmega128L has a maximum clock speed of 8 MHz, I’d say there is a pretty extreme mismatch in potential data rate between the ADC and the controller- wouldn’t you want something a little faster for this ADC?
The AVR is connected to the control interface to configure the chip. The ADC samples come out of a different high speed LVDS interface.
The current ADC P/N is AT84AD001C, the B model is not recommended for new designs. The ADC is currently owned/made by the U.K. company e2v (which is ex-Marconi Group). These parts are fairly hard to find and run around $120-$150 USD each in unit quantity (AVNET) depending on specific P/N, with a (roughly) 20% break at 1,000 quantity.
Personally, I don’t understand the interest in posting this AN here on DP. Any bubblegum uC can be used to supervise this ADC. I’d rather see an AN on a high-speed interleaved ADC reference design with an Eval Kit board layout.