netX 90 in Motion
The netX 90 is a multiprotocol communication SoC with built-in motor control for motion and drive applications, featuring up to 1.5 MB Flash memory, integrated Ethernet PHYs, built-in security and diagnostics, on-chip DC/DC converter with POR circuit, analog BOD function for higher voltages, and a feature-rich set of on-chip peripherals with connectivity. As illustrated in Figure 1, the SoC architecture is composed of a communication subsystem (left-hand side), a block of shared functions (bottom, center), and an application host (right-hand side):
- The communication segment features two flexible communication (xC) channels with switch and IEEE 1588 support for all widely used industrial real-time communication protocols.
- The block of shared functions serves both segments of the chip, depending on the application use case. Integrated firewalls in front of each shared peripheral regulate access rights.
- The application segment features a second Cortex®-M4 at 100 MHz with DSP and FPU support, enhanced by a set of on-chip peripherals for motion and motor control applications.
Figure 1: netX 90 block diagram with highlighted motion and motor control-related peripheral features
The data exchange with the protocol stack interface using the internal DPM (iDPM) eliminates access latencies for single-cycle CPU access. The virtual DPM comprises up to 32 KB SRAM with handshake cell registers and IRQ support, including a hardware-assisted network synchronization generated by the xC trigger unit. The exact use of the hardware-assisted synchronization depends on the supported feature set of the real-time communication protocol standard and the underlying device configuration for the network connection with the PLC.
Figure 2: Hardware-assisted synchronization between FOC, MPWM, MADC, and PSE for application profiles
The built-in motion and motor control application enables for instance the implementation of a field-oriented control (FOC) algorithm with position feedback to drive a 3-phase PMSM or BLDC motor. The supported peripheral feature set includes:
1. Motion Pulse-Width Modulation (MPWM):
- 6+1 channel MPWM
- 10 ns resolution
- “Classic” center-aligned mode
- Automatic dead-time insertion, 0% and 100% duty cycle support
- Software-defined free form mode
- Arbitrary dead time compensation algorithms
- Update every half, full or nth period
- Low to high PWM frequency with single IRQ per current control loop
- FAULT input independent of clock
2. Motion Analog-to-Digital Converter (MADC):
- 4x ADC with sample & hold
- 12-bit resolution and up to 2 MS/s
- 20 input channels (2+2+8+8)
- Simultaneous measurement of
- 2 of 3 motor currents and one SinCos encoder
- 2 SinCos encoders
- 4x ADC controller with DMA
- 8 triggers per ADC
- Triggers on PWM phase, 6 dead times or network
- Up to 32 (8x4) measurements per PWM (half) cycle with a single IRQ per current loop, e.g. motor currents, phase voltages, DC-Link, 2x SinCos, temperature, etc.
3. Motion Encoder (MENC) Interface:
- 2x quadrature encoder interfaces
- 3 input channels (A, B and N) per encoder module
- 2 encoder filters
- 4 capture units
- High resolution for more accurate determination of position or speed
- Zero reference input for the precise determination of an absolute reference position
- A digital glitch filter to reduce the impact of system-generated noise
4. EnDat 2.2 Interface for Encoders:
- 2x EnDat master E6 basic interfaces
- Supported protocols EnDat2.2 and SSI
- Clock rate of up to 16 MHz
5. BiSS Interface for Encoders:
2x BiSS MB-100 master interfaces
- Supported protocols BiSS C and SSI
Cyclic transfer at data rates of up to 10 Mbit/s
- 8x GPIO with event counters
- Event time capture
- Active time measurement
- Capture counter on edge or level
- Capture counter once or continuously
- Count external events (edges or duration of level)