Multi-Chip Synchronization (MCS) is critical in high-performance RF systems where multiple transceiver chips must work in harmony. Whether you’re building a phased array radar or a multi-channel communication system, precise phase alignment between chips ensures predictable, repeatable performance. With MCS enabled, your Tx/Rx chains are not only in sync—they’re locked in time and phase, providing the foundation for accurate, scalable RF designs.
In this guide, you walk through the process of customizing Analog Devices’ Kuiper Linux and enabling MCS on the ZCU102 FPGA platform with the ADRV9002. Whether you’re debugging signal alignment or building a time-sensitive RF testbed, this “how-to” puts you in control—step by step.
Step 1: Customize the Kernel for MCS Initialization
Your first task is to ensure the ADRV9002 halts at the CALIBRATED state—this is where MCS must be activated.
- Open the Analog Devices’ Linux kernel source.
- Navigate to the driver path:
linux/drivers/iio/adc/navassa/adrv9002.c
- Modify the state transition logic so the initialization stops at:
ADI_ADRV9001_CHANNEL_CALIBRATED
- Save, recompile the kernel, and copy the new image to your SD card’s /boot directory.
Why this matters: If the device moves past CALIBRATED to RF_ENABLED, you won’t be able to properly apply MCS later.
Step 2: Build the Vivado Project for Signal Handling
In Vivado, design a custom hardware block to:
- Write test data from the OS into BRAM.
- Trigger data transmission via VIO control.
- Transmit data using ADRV9002’s Tx.
- Loop back the signal to Rx and measure delay or phase offsets.
This custom logic gives you a reliable loopback path for verifying synchronization.
Figure 1. Vivado Block design for MCS project
Step 3: Load a JSON Profile with MCS Enabled
Generate a profile in TES (Transceiver Evaluation Software) with:
- SSI Mode: LVDS
- Data Rate: DDR
- MCS: Enabled with phase synchronization
Transfer the .json file to the target via SD card and load it using IIO Oscilloscope:
- Go to the adrv9002 tab and click Load Profile.
- Select your custom JSON profile.
Step 4: Enable MCS via system Attribute
Now activate MCS:
echo 1 > /sys/bus/iio/devices/iio:device1/multi_chip_sync &
Step 5: Send Synchronization Pulses
Use a simple script to generate sync pulses:
- Place script.sh on your board
- Make it executable:
chmod +x script.sh
- Run it within 10 seconds after enabling MCS:
./script.sh
Timing here is key—the sync pulse must align with the system’s readiness.
Step 6: Move to RF_ENABLED State
Using IIO Scope:
- Go to each channel.
- Set the ENSM (Enable State Machine) mode to RF_ENABLED.
This finalizes your transceiver setup.
Data Handling & Signal Verification
Use a utility script to load test data into BRAM:
cd /home/analog/Downloads/Documents/PS_BRAM_Tx
sudo ./WriteDeviceWord
Then observe the received waveform to confirm successful MCS.
Observations
- 400 MHz LO frequency consistent phase and delay.
- Changing the LO frequency introduces a new phase offset.
- Keeping the LO fixed? The system produces identical results across repeated Tx/Rx cycles—your MCS is working.
From Figure 2, you can clearly observe that the phase delay is fixed once it powers on and keeps a constant phase delay. This phase varies after every power cycle.
Figure 2. At 400 MHz
Conclusion: Why This Is a Game-Changer
You've created a deterministic, phase-aligned RF system by successfully customizing the Linux kernel, configuring the hardware, and enabling MCS. This isn’t just a tech win—it’s a foundation for multi-channel synchronization in radar, 5G, or communication systems.
Congrats! You’ve just brought precision timing and synchronization into your workflow—unlocking a whole new level of reliability and scalability in RF design.