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

6. Enhanced GPIOs with Timer:

• 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)