AD9629BCPZ-80 Datasheet, PDF (29/32 Pages) Analog Devices – 12-Bit, 20 MSPS/40 MSPS/65 MSPS/80 MSPS, 1.8 V Analog-to-Digital Converter

MEMORY MAP REGISTER DESCRIPTIONS
For additional information about functions controlled in
Register 0x00 to Register 0xFF, see the AN-877 Application
Note, Interfacing to High Speed ADCs via SPI.
USR2 (Register 0x101)
Bit 3—Enable GCLK Detect
Normally set high, this bit enables a circuit that detects encode
rates below about 5 MSPS. When a low encode rate is detected,
an internal oscillator, GCLK, is enabled ensuring the proper
operation of several circuits. If set low the detector is disabled.
AD9629
Bit 2—Run GCLK
This bit enables the GCLK oscillator. For some applications
with encode rates below 10 MSPS, it may be preferable to set
this bit high to supersede the GCLK detector.
Bit 0—Disable SDIO Pull-Down
This bit can be set high to disable the internal 30 kΩ pull-down
on the SDIO pin, which can be used to limit the loading when
many devices are connected to the SPI bus.
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