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--- en:example_of_development_around_the_ad9959_dds [2016/03/14 08:34]
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 The DDS is part of a series of specific components of Analog Device , this program only in serial (SPI) knowing that others DDS accept two modes: SPI and Parallel. The clock frequency is 500MHz and it can provide four output RF : DC- 200MHz . I will introduce the basic elements for the DDS program knowing that it can be applied to other DDS from the same family . Below doc of the AD9959 .
 {{:en:ad9959.pdf|}}
+The DDS was programmed via a 16-bit microcontroller from TI MSP430F169 to the 8MHz clock : http://www.ti.com/lit/ds/symlink/msp430f1611.pdf .
+The MSP430 programming environment IAR Workbench Embdedded downloaded from the Texas Instruments website . http://www.iar.com/Products/IAR-Embedded-Workbench/TI-MSP430
+I recommend buying the MSP430USB debugging kit that allows MSP- FET430UIF a step by step debugging if you want to use this microcontroller family .
+Of course many other microcontroller can beings used from the time that we have at least a SPI port. In this case a development with The AD9959 has been realized with Atmel microcontroller Arduino due, Microcontroller 32-bit ARM core @ 84MHz SPI clock and son loading 4wires .
+The latest developments in electronic service have made summers with an ARM Cortex 4 @ 80MHz Tiva IT TM4C123GH6PM series. http://www.ti.com/tool/EK-TM4C123GXL with the AD9852, AD9911 to the AD9959 and AD9858 from Analog Device.
+I will present the latest developments with DDS as a programming interface ARM Cortex microcontroller 4 @ 80MHz Tiva IT TM4C123GH6PM series.
+===How to read the datasheet of a DDS!===
+The different registers of DDS: the AD9959
+The first register to be programmed is the CSR register: Table 28 datasheet
+    CSR register (channel select register)
+    One byte is assigned to When this register: number of register bytes
+    CSR serial address = 0x00;
+    CSR default value = 0xF0;
+This activates the register output channels and SPI modes: By default all channels are activated, and the SPI mode Single-bit serial 2-wire is selected. It is obviously possible to redefine the register after application.
+The second register is the register FR1: Table 28 datasheet
+    register FR1 (function register 1)
+    three bytes is assigned to When this register: number of register bytes
+    FR1 serial address = 0x01;
+    FR1 default value = 0x00;
+This registry allows others to define the internal PLL and the multiplier x4 to x20. For example, the value to be provided to enable EN1 = x20 ⇒ 0xD00000 PLL; In this case it is sufficient to provide a quartz 25MHz PLL with activated PIN x20 clock was 500MHz 22 and 23 of the DDS.
+The third register is the register table CFR 29 datasheet
+    register CFR (Channel Function Register)
+    three bytes is assigned to When this register: number of register bytes
+    CFR serial address = 0x03;
+    CFR default value = 0x302;
+This register defines the different register DDS.Ce operating mode is important if you use certain
+modes of operation: frequency sweep, phase or amplitude. Important default output are
+DAC full-scale current mode.
+The fourth register is the register CFTW0: Table 29 datasheet
+    CFTW0 register (Channel Frequency Tuning Word 01)
+    oven bytes is assigned to When this register: number of register bytes
+    CFTW0 serial address = 0x04;
+    CFTW0 default value = 0x00;
+This register to return the desired frequency according to the relation below:
+    FTW0 = output frequency x 2 ^ 32 / frequency clock
+The registry is the fifth CPOW0 table 29 of the datasheet register
+    CPOW0 register (Channel Phase Offset Word 01)
+    two bytes is assigned to When this register: number of register bytes
+    CPOW0 serial address = 0x05;
+    CPOW0 default value = 0x00;
+This register defines the phase of the output signal coded on 14 bits with the following relationship:
+    CPOW0 Delta phi = x ^ 2 14/360 °
+The sixth register is the ACR register: Table 29 datasheet
+    ACR register (Amplitude Control Register)
+    two bytes is assigned to When this register: number of register bytes
+    CAB serial address = 0x06;
+    ACR default value = 0x00;
+This register sets the amplitude. By default amplitude is programmable full scale mode, but if you change the CFR register.
+The other registers are useful to program the DDS for scans frequencies, phases and amplitudes in others.
+    FR2 register (Function Register 2)
+    LSRR register (Linear Sweep Ramp Rate1)
+    FDW register (LSR Falling delta word1)
+    RDW register (LSR Risingdelta word1)
+    CW1 register (Channel Word 1)
+    ...

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