AD9272 Analog Devices, AD9272 Datasheet - Page 40

• Manufacturer Part Number: AD9272
• Description: Octal LNA/VGA/AAF/ADC and Crosspoint Switch
• Manufacturer: Analog Devices

Specifications of AD9272

• Resolution (bits): 12bit
• # Chan: 8
• Sample Rate: 80MSPS
• Interface: LVDS,Ser
• Analog Input Type: SE-Uni
• Ain Range: 367 mV p-p,550 mV p-p,733 mV p-p
• Adc Architecture: Pipelined
• Pkg Type: QFP

AD9272
MEMORY MAP
READING THE MEMORY MAP TABLE
Each row in the memory map table has eight address locations.
The memory map is roughly divided into three sections: the
chip configuration register map (Address 0x00 to Address 0x02),
the device index and transfer register map (Address 0x04 to
Address 0xFF), and the ADC functions register map (Address
0x08 to Address 0x2D).
The leftmost column of the memory map indicates the register
address number, and the default value is shown in the second
rightmost column. The Bit 7 (MSB) column is the start of the
default hexadecimal value given. For example, Address 0x09,
the clock register, has a default value of 0x01, meaning that Bit 7
= 0, Bit 6 = 0, Bit 5 = 0, Bit 4 = 0, Bit 3 = 0, Bit 2 = 0, Bit 1 = 0,
and Bit 0 = 1, or 0000 0001 in binary. This setting is the default
for the duty cycle stabilizer in the on condition. When a 0 is
written to Bit 0 of this address followed by an 0x01 to the SW
transfer bit in Register 0xFF, the duty cycle stabilizer turns off. It
is important to follow each writing sequence with a write to the
SW transfer bit to update the SPI registers.
Rev. C | Page 40 of 44
Caution
All registers except Register 0x00, Register 0x02, Register 0x04,
Register 0x05, and Register 0xFF are buffered with a master
slave latch and require writing to the transfer bit. For more
information on this and other functions, consult the AN-877
Application Note, Interfacing to High Speed ADCs via SPI.
RESERVED LOCATIONS
Undefined memory locations should not be written to except
when writing the default values suggested in this data sheet.
Addresses that have values marked as 0 should be considered
reserved and have a 0 written into their registers during power-up.
DEFAULT VALUES
After a reset, critical registers are automatically loaded with
default values. These values are indicated in Table 17, where an
X refers to an undefined feature.
LOGIC LEVELS
An explanation of various registers follows: “bit is set” is
synonymous with “bit is set to Logic 1” or “writing Logic 1 for
the bit. ” Similarly, “clear a bit” is synonymous with “bit is set to
Logic 0” or “writing Logic 0 for the bit. ”