CDCE62005 Datasheet, PDF (23/76 Pages) Texas Instruments – Five/Ten Output Clock Generator/Jitter Cleaner With Integrated Dual VCOs

CDCE62005
www.ti.com........................................................................................................................................................................................... SCAS862 – NOVEMBER 2008
INTERFACE AND CONTROL BLOCK
The Interface & Control Block includes a SPI interface, four control pins, a non-volatile memory array in which
the device stores default configuration data, and an array of device registers implemented in Static RAM. This
RAM, also called the device registers, configures all hardware within the CDCE62005.
REF_SELECT
/Power_Down
/SYNC
SPI_LE
SPI_CLK
SPI_MISO
SPI_MOSI
Interface
&
Control
Static RAM (Device Registers)
Register 8
Register 7
Register 6
Register 5
Register 4
Register 3
Register 2
Register 1
Register 0
Device
Hardware
EEPROM (Default Configuration)
Register 7
Register 6
Register 5
Register 4
Register 3
Register 2
Register 1
Register 0
Figure 18. CDCE62005 Interface and Control Block
SPI (Serial Peripheral Interface)
The serial interface of CDCE62005 is a simple bidirectional SPI interface for writing and reading to and from the
device registers. It implements a low speed serial communications link in a master/slave topology in which the
CDCE62005 is a slave. The SPI consists of four signals:
• SPI_CLK: Serial Clock (Output from Master) – the CDCE62005 clocks data in and out on the rising edge of
SPI_CLK. Data transitions therefore occur on the falling edge of the clock.
• SPI_MOSI: Master Output Slave Input (Output from Master) .
• SPI_MISO: Master Input Slave Output (Output from Slave)
• SPI_LE: Latch Enable (Output from Master). The falling edge of SPI_LE initiates a transfer. If SPI_LE is high,
no data transfer can take place.
The CDCE62005 implements data fields that are 28-bits wide. In addition, it contains 9 registers, each
comprising a 28 bit data field. Therefore, accessing the CDCE62005 requires that the host program append a
4-bit address field to the front of the data field as follows:
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