The RM44Lx20 device is part of the Hercules RM series of high-performance industrial-grade
ARM® Cortex®-R-based MCUs. Comprehensive documentation, tools, and software
are available to assist in the development of IEC 61508 functional
safety applications. Start evaluating today with the Hercules RM LaunchPad Development Kit. The RM44Lx20 device has
on-chip diagnostic features including: dual CPUs in lockstep; CPU and memory
Built-In Self-Test (BIST) logic; ECC on both the flash and the SRAM; parity
on peripheral memories; and loopback capability on most peripheral I/Os.
The RM44Lx20 device integrates the ARM Cortex-R4F floating-point CPU
which offers an efficient 1.66 DMIPS/MHz, and has configurations which can
run up to 180 MHz providing up to 298 DMIPS. The RM44Lx20 device supports
the little-endian [LE] format.
The RM44Lx20 device has up to 1MB of integrated flash and 128KB of
RAM configurations with single-bit error correction and double-bit error
detection. The flash memory on this device is nonvolatile, electrically
erasable and programmable, and is implemented with a 64-bit-wide data bus
interface. The flash operates on a 3.3-V supply input (same level as the I/O
supply) for all read, program, and erase operations. The SRAM supports
single-cycle read and write accesses in byte, halfword, word, and doubleword
modes throughout the supported frequency range.
The RM44Lx20 device features peripherals for real-time control-based
applications, including two Next-Generation High-End Timer (N2HET) timing
coprocessors with up to 44 total I/O terminals, seven Enhanced PWM (ePWM)
modules with up to 14 outputs, six Enhanced Capture (eCAP) modules, two
Enhanced Quadrature Encoder Pulse (eQEP) modules, and two 12-bit
Analog-to-Digital Converters (ADCs) supporting up to 24 inputs.
The N2HET is an advanced intelligent timer that provides sophisticated
timing functions for real-time applications. The timer is
software-controlled, using a reduced instruction set, with a specialized
timer micromachine and an attached I/O port. The N2HET can be used for
pulse-width-modulated outputs, capture or compare inputs, or general-purpose
I/O (GIO). The N2HET is especially well suited for applications requiring
multiple sensor information and drive actuators with complex and accurate
time pulses. A High-End Timer Transfer Unit (HTU) can transfer N2HET data to or
from main memory. A Memory Protection Unit (MPU) is built into the HTU.
The ePWM module can generate complex pulse width waveforms with minimal
CPU overhead or intervention. The ePWM is easy to use and supports
complementary PWMs and deadband generation. With integrated trip zone
protection and synchronization with the on-chip MibADC, the ePWM is ideal
for digital motor control applications.
The eCAP module is essential in systems where the accurately timed capture
of external events is important. The eCAP can also be used to monitor the
ePWM outputs or to generate simple PWM when not needed for capture
The eQEP module is used for direct interface with a linear or rotary
incremental encoder to get position, direction, and speed information from a
rotating machine as used in high-performance motion and position-control
The device has two 12-bit-resolution MibADCs with 24 total inputs and 64
words of parity-protected buffer RAM each. The MibADC channels can be
converted individually or can be grouped by software for sequential
conversion sequences. Sixteen inputs are shared between the two MibADCs. There
are three separate groups. Each group can be converted once when triggered
or configured for continuous conversion mode. The MibADC has a 10-bit mode
for use when compatibility with older devices or faster conversion time is
The device has multiple communication interfaces: three MibSPIs; two SPIs;
two SCIs, one of which can be used as LIN; up to three DCANs; and one I2C
module. The SPI provides a convenient method of serial interaction for
high-speed communications between similar shift-register type devices. The
LIN supports the Local Interconnect standard 2.0 and can be used as a UART
in full-duplex mode using the standard Non-Return-to-Zero (NRZ) format. The
DCAN supports the CAN 2.0B protocol standard and uses a serial, multimaster
communication protocol that efficiently supports distributed real-time
control with robust communication rates of up to 1 Mbps. The DCAN is ideal
for applications operating in noisy and harsh environments (for example,
automotive and industrial fields) that require reliable serial communication or
The I2C module is a multimaster communication module providing an
interface between the microcontroller and an I2C-compatible
device through the I2C serial bus. The I2C module supports speeds
of 100 and 400 kbps.
A Frequency-Modulated Phase-Locked Loop (FMPLL) clock module is used to
multiply the external frequency reference to a higher frequency for internal
use. The FMPLL provides one of the six possible clock source inputs to the
Global Clock Module (GCM). The GCM manages the mapping between the available
clock sources and the device clock domains.
The device also has an external clock prescaler (ECP) circuit that when
enabled, outputs a continuous external clock on the ECLK terminal. The ECLK
frequency is a user-programmable ratio of the peripheral interface clock (VCLK)
frequency. This low-frequency output can be monitored externally as an
indicator of the device operating frequency.
The Direct Memory Access (DMA) controller has 16 channels, 32 peripheral
requests, and parity protection on its memory. An MPU is built into the DMA
to protect memory against erroneous transfers.
The Error Signaling Module (ESM) monitors device errors and determines
whether an interrupt or external error signal (nERROR) is asserted when a
fault is detected. The nERROR terminal can be monitored externally as an
indicator of a fault condition in the microcontroller.
With integrated functional safety features and a wide choice of communication
and control peripherals, the RM44Lx20 device is an ideal solution for
high-performance, real-time control applications with safety-critical