This version (08 Jan 2016 10:38) was approved by Lars-Peter Clausen.
Table of Contents
CN0363 Phase Data Sync FPGA Peripheral
The CN0363 Phase Data Sync FPGA Peripheral is part of the EVAL-CN0363-PMDZ HDL reference design and is responsible for preparing the ADC conversion result data and aligning it with the phase and feeding both to the processing pipeline.
Files
| Name | Description |
|---|---|
| cn0363_phase_data_sync.v | Verilog source for the peripheral. |
| cn0363_phase_data_sync_ip.tcl | TCL script to generate the Vivado IP-integrator project for the peripheral. |
Signal and Interface Pins
| Name | Type | Description |
|---|---|---|
clk | Clock | All other signals are synchronous to this clock. |
resetn | Synchronous active low reset | Resets the internal state machine of the core. |
processing_resetn | Synchronous active low reset | Indicator that the processing pipeline is in reset. |
S_AXIS_SAMPLE | AXI-Stream slave | Input sample data stream |
M_AXIS_SAMPLE | AXI-Stream master | Output sample data stream |
M_AXIS_PHASE | AXI-Stream master | Output phase data stream |
sample_has_stat | Input | Whether the incoming data on S_AXIS_SAMPLE has the STAT register appended. |
conv_done | Input | Conversion done signal from the ADC. |
phase | Input | Current excitation signal phase. |
overflow | Input | The overflow signal is asserted if a new sample arrives before the previous one has been consumed. |
Theory of Operation
The CN0363 Phase Data Sync FPGA Peripheral takes the raw ADC sample data read by a SPI controller from the ADC on the S_AXIS_SAMPLE stream. The data is assembled into 24-bit word and converted from offset binary to two's complement signed.
When a rising edge is detected on the conv_done signal the core takes a snapshot of the phase input signal. This data will be assumed to the phase that belongs to the next incoming data sample on the S_AXIS_SAMPLE. The data is aligned with the corresponding phase data and both are send out on the M_AXIS_SAMPLE and M_AXIS_PHASE stream.
If the sample_has_stat signal is asserted the core will receive 32-bit instead of 24-bit per sample on the S_AXIS_SAMPLE stream. The last 8-bit are assumed to contain the STAT register of the ADC, which among other things contains the information about which channel the ADC result belongs to. This information can be used to detect and fix channel swaps. If sample_has_stat is not asserted the core assumes that no channel swaps happen and the whole pipeline is always running fast enough to accept a sample before the next one is ready.
If processing_resetn is asserted the processing pipeline is assumed to be in reset and incapable of accepting new samples and when a new sample arrives at the S_AXIS_SAMPLE port a overflow condition is generated. The signal also resets the channel swap detection logic and makes sure that the next sample that is inserted into the processing pipeline after the reset belongs to the first channel.
More Information
resources/fpga/peripherals/cn0363/phase_data_sync.txt · Last modified: 27 May 2015 16:50 by Lars-Peter Clausen