The RM46L852 device is a high-performance microcontroller family for
safety systems. The safety architecture includes dual CPUs in lockstep, CPU
and memory BIST logic, ECC on both the flash and the data SRAM, parity on
peripheral memories, and loopback capability on peripheral I/Os.
The RM46L852 device integrates the ARM Cortex-R4F floating-point
CPU which offers an efficient 1.66 DMIPS/MHz, and can run up to 220 MHz
providing up to 365 DMIPS. The device supports the little-endian [LE]
The RM46L852 device has 1.25MB of integrated flash and 192KB of
data RAM with single-bit error correction and double-bit error detection. The
flash memory on this device is a nonvolatile, electrically erasable and
programmable memory, implemented with a 64-bit-wide data bus interface. The
flash operates on a 3.3-V supply input (same level as I/O supply) for all
read, program, and erase operations. When in pipeline mode, the flash
operates with a system clock frequency of up to 220 MHz. The SRAM supports
single-cycle read and write accesses in byte, halfword, word, and double-word
modes throughout the supported frequency range.
The RM46L852 device features peripherals for real-time control-based
applications, including two Next Generation High-End Timer (N2HET) timing
coprocessors with up to 44 I/O terminals, seven Enhanced Pulse Width
Modulator (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 perform DMA-type transactions to transfer N2HET data
to or from main memory. A Memory Protection Unit (MPU) is built into the
The ePWM module can generate complex pulse width waveforms with minimal
CPU overhead or intervention. The ePWM is easy to use and it supports both
high-side and low-side PWM and deadband generation. With integrated trip zone
protection and synchronization with the on-chip MibADC, the ePWM module 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 for simple PWM generation when the eCAP is not needed for
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.
Each MibADC supports three separate groupings of channels. 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 desired. MibADC1 also supports the use of
external analog multiplexers.
The device has multiple communication interfaces: three MibSPIs, two
SPIs, one LIN, one SCI, three DCANs, one I2C, one
Ethernet, and one USB module. The SPI provides a convenient method of serial
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 2.0 (A and B) 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 systems operating in noisy and harsh environments (for example,
automotive and industrial fields) that require reliable serial communication
or multiplexed wiring. The Ethernet module supports MII, RMII, and MDIO
The USB module includes a 2-port USB host controller that is revision
2.0-compatible, based on the OHCI specification for USB, release 1.0. The USB
module also includes a USB device controller compatible with the USB
specification revision 2.0 and USB specification revision 1.1.
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 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 Global Clock Module (GCM) manages the mapping between the available
clock sources and the device clock domains.
The device also has an External Clock Prescaler (ECP) module 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 all device errors and determines
whether an interrupt or external error pin (ball) is triggered when a fault
is detected. The nERROR terminal can be monitored externally as an indicator
of a fault condition in the microcontroller.
The External Memory Interface (EMIF) provides a memory extension to
asynchronous and synchronous memories or other slave devices.
A Parameter Overlay Module (POM) enhances the calibration capabilities of
application code. The POM can reroute flash accesses to internal memory or to
the EMIF, thus avoiding the reprogramming steps necessary for parameter
updates in flash.
With integrated safety features and a wide choice of communication and
control peripherals, the RM46L852 device is an ideal solution for
high-performance real-time control applications with safety-critical
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