The MX102 is the interface between the Controller Area Network (CAN) protocol controller and the physical bus. It is primarily intended for high speed applications, up to 1 Mbps, in passenger cars. The device provides differential transmit capability to the bus and differential receive capability to the CAN controller. The MX102 also features a very low current standby mode with remote wake up capability via the bus.
The IP is a complete Digital Precorrection(Predistortion) system designed to compensate for the non-linear characteristic of a high-power RF Amplifier. The system is capable of adjusting both the gain and phase of a complex input signal. This is achieved by means of a complex multiplication of the input with a complex polynomial function stored in the LT.
The LT contains the inverse PA characteristic and is applied before the amplification stages (either at baseband or IF frequencies). By programming the LT with the inverse gain/phase PA response, the resultant PA response is linearized. After linearization, the output signal is much cleaner with reduced intermodulation distortion.
The system may be used in open-loop or closed-loop configuration. For open loop operation, the LUT coefficients are static and programmed during initial setup of the PA precorrection system. For closed-loop operation, an external circuit may compare the baseband inputs and PA outputs and adjust the LUT coefficients dynamically in order to automate the linearization process.
Precorrection of wide bandwidth signals such as UMTS, WCDMA and OFDM
Power amplifier linearization for mobile Base-stations, Broadcasting etc.
Precorrection of any type of digitally modulated signal where the signal envelope varies and therefore the instantaneous input power.
The IP Core is a high-precision Direct Digital Synthesizer 2 used for the generation of periodic waveforms. On each rising-edge of the sample clock, the phase in the phase accumulator is incremented by the value phase_inc. This phase is quantized to 16-bits and passed as an address to a look-up table which converts the phase into a waveform.
In addition to the quadrature outputs sin_out and cos_out, the IP also provides square wave and sawtooth outputs: squ_out and saw_out. All output values are 16-bit signed numbers.
Digital up/down converters and mixers
Versatile waveform generation
The IP is a precision tone decoder with the capacity to support either real or complex data samples. Samples are first mixed-down to baseband before subsequent filtering and tone detection.
The centre frequency of the tone is fully programmable and is generated by a local oscillator (DDS). The DDS has an SFDR of better than 80 dBs (with phase dithering) and a theoretical SNR of approximately 100 dBs.
After down-conversion, 2 paths are filtered to remove components above the tone of interest. The characteristics of these filters may be changed depending on the desired detection bandwidth and
Finally, a power function is used to compute the relative magnitude of the signal after filtering.
Precision frequency monitoring and control
FSK / OOK / ASK demodulation
Touch tone decoding (e.g. DTMF tones)
Complex digital down conversion
This is a polyphase decimation filter that permits the down-sampling of an input signal by any power of 2. The filter core is organized as a highly optimized systolic array, allowing the user to specify very large decimation factors while keeping resource costs to a minimum.
Input data is sampled on the rising clock-edge of clk when CLK_EN is active high. Internally, the samples are filtered and decimated then presented at the output interface, Y_OUT.The output signal EN_OUT is the output clock-enable signal that indicates when an output sample is valid.
Decimation by a wide range of factors from 2 to 2N
Reduction of input sample rate to make subsequent signal processing easier
Decimation of signals after digital-down-conversion
The IP is an N-channel multiplexed FIR filter designed for high sample rate applications where hardware resources are limited. The main filter core is organized as a scalable systolic array permitting the user to specify large order filters without compromising maximum attainable clock-speed.
Essentially the filter functions as if it were 'N' separate FIR filters. Each input sample is multiplexed into the filter at a sample rate equal to Fs /N,
where Fs is the sampling frequency of the main filter core. Likewise, output samples are updated at a frequency of Fs /N.
The first sample into the filter is aligned by asserting the signal X_VALID high. The signal Y_VALID_val is asserted with the first valid output sample. Data samples are advanced in the pipeline on the rising clock-edge of clk when en is active high. When en is low then all data samples are stalled. The clock-enable signal may be used to temporarily disable the filter - or possibly to modify the effective sampling frequency of the system clock. If the clock-enable is not needed it is recommended that this signal be tied high as it will improve overall circuit performance.
Dual-channel inputs such as complex valued I/Q in digital communications systems
High-speed filtering applications where hardware resources are limited
General purpose FIR filters with odd or even numbers of taps
FIR_F is an FIR filter implementation designed for very high sample rate applications. Organized as a systolic array the filter is modular and fully scalable, permitting the user to specify large order filters without compromising maximum attainable clock-speed. Mathematically, the filter implements the difference equation:
y[n] = h0 x[n] + h1 x[n−1] + ... + hN x[n−N ]
In the above equation, the input signal is x[n], the output signal is y[n] and h0 to hN represent the filter coefficients. The number N is the filter order, the number of filter taps being equal to N+1.
General purpose FIR filters with odd or even numbers of taps
Filters with arbitrary sets of coefficients
Very high-speed filtering applications
Digital Down Converter with configurable Decimation Filter
DDC is a complex-valued digital down-converter with a configurable number of decimation stages. The design is ideal for high sample-rate applications and permits a digital input signal to be mixed-
down and re-sampled at a lower data rate. The DDC is suitable for the down-conversion of any digitally modulated signal to baseband – an essential step before digital processing.
The DDC features a high-precision 16-bit DDS oscillator for the digital mixing stage. This oscillator is fully programmable and offers excellent phase and frequency resolution. The digital mixing stage is a complex multiplier that allows the mixing of both real and imaginary (I/Q) inputs. If only real inputs are required, then the imaginary input (q_in) should be tied low.
The output decimation stage features a configurable decimate-by-2N poly-phase filter for both I and Q channels. Each filter stage is highly optimized to use only 12 multipliers while still achieving 80 dB of stop-band attenuation.
Compatible with any digital modulation scheme - e.g. QPSK, BPSK, QAM, WiMAX, WCDMA, COFDM etc.
Conversion of IF signals to baseband frequencies for subsequent processing
Digital I/Q Demodulators
IP is a Binary-PSK demodulator based on a multiply-filter-divide architecture. The design is robust and flexible and allows easy connectivity to an external ADC.
As the the carrier recovery circuit is open-loop, there is no feedback path or loop-filter to configure. This results in an extremely simple circuit with a very fast carrier acquisition time. The only requirement is that the user set the desired symbol period and a suitable threshold level for the bit decisions at the symbol decoder. The other design parameters including carrier frequency, symbol rate and sampling frequency should be specified by the user before delivery of the IP Core 1 .
The input data samples are 16-bit signed (2's complement) values that are synchronous with the system clock. Input values are sampled on the rising edge of clk when en is high.
Robust, low bandwidth RF applications for small FPGA devices
SRD and ISM band devices
Medium to long-range telemetry
This IP is a precision Binary-FSK Demodulator IP Core based on a non-coherent receiver design. The demodulator is fully programmable, allowing for a varied range of symbol rates and mark/space tone frequencies. Input data samples may be either complex or real for support of either passband or baseband signals. The module allows easy connectivity to an external ADC with up to 16-bit signed input samples.
Short range telemetry