Design Overview (AxelLite)

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Axel-lite 02.png Applies to Axel Lite

The new documentation is available here: AXEL_Lite_SOM/AXEL_Lite_Hardware/General_Information/Processor_and_memory_subsystem

Design Overview[edit | edit source]

The heart of Axel Lite module is composed by the following components:

  • Freescale i.MX6 Solo / Dual / Quad core SoC application processor
  • Power supply unit
  • DDR memory banks
  • NOR and NAND flash banks
  • 1x 204 pin SODIMM connector with interfaces signals

This chapter shortly describes the main Axel Lite components.

Processor Info[edit | edit source]

The i.MX6 Solo/Dual/Quad processors feature Freescale’s advanced implementation of the ARM® Cortex®-A9 MPCore, which operates at speeds up to 1.2 GHz. They include 2D and 3D graphics processors, 1080p video processing, and integrated power management. As a result, the i.MX6 devices are able to serve a wide range of applications including:

  • Automotive driver assistance, driver information, and infotainment
  • Multimedia-centric smart mobile devices
  • Instrument clusters, and portable medical devices.
  • E-Readers, smartbooks, tablets
  • Intelligent industrial motor control, industrial networking, and machine vision
  • IP and Smart camera
  • Human-machine interfaces
  • Medical diagnostics and imaging
  • Digital signage
  • Video and night vision equipment
  • Multimedia-focused products
  • Entertainment and gaming appliances

The i.MX6 application processor is composed of the following major functional blocks:

  • ARM Cortex-A9 MPCore 1x/2x/4x CPU Processor, featuring:
    • 1 Megabyte unified L2 cache shared by all CPU cores
    • NEON MPE coprocessor
    • General Interrupt Controller (GIC) with 128 interrupt support
    • Snoop Control Unit (SCU)
    • External memories interconnect
  • Hardware accelerators, including:
    • VPU -Video Processing Unit
    • Two IPUv3H -Image Processing Unit (version 3H)
    • 2D/3D/Vector graphics accelerators
  • Connectivity peripherals, including
    • PCIe
    • SATA
    • Serial buses: USB, UART, I²C, SPI, ...

Axel Lite can mount three versions of the i.MX6 processor. The following table shows a comparison between the processor models, highlighting the differences:

Processor # Cores Clock L2 Cache DDR3 Graphics Acceleration IPU VPU SATA-II
i.MX6 Solo 1 800 MHz
1 GHz
512 KB 32 bit @ 400 MHz 3D: Vivante GC880
2D: Vivante GC320
Vector: N.A.
1x 1x N.A.
i.MX6 Dual 2 850 MHz
1 GHz
1.2 GHz
1 MB 64 bit @ 533 MHz 3D: Vivante GC2000
2D: Vivante GC320
Vector: Vivante GC335
2x 2x Yes
i.MX6 Quad 4 850 MHz
1 GHz
1.2 GHz
1 MB 64 bit @ 533 MHz 3D: Vivante GC2000
2D: Vivante GC320
Vector: Vivante GC335
2x 2x Yes
Table: i.MX6 models comparison

RAM memory bank[edit | edit source]

DDR3 SDRAM memory bank is composed by 4x 16-bit width chips resulting in a 64-bit combined width bank. The following table reports the SDRAM specifications:

CPU connection Multi-mode DDR controller (MMDC)
Size min 512 MB
Size max 4 GB
Width 64 bit
Speed 533 MHz

NOR flash bank[edit | edit source]

NOR flash is a Serial Peripheral Interface (SPI) device. This device is connected to the eCSPI channel 5 and by default it acts as boot memory. The following table reports the NOR flash specifications:

CPU connection eCSPI channel 5
Size min 8 MB
Size max 64 MB
Chip select ECSPI5_SS0
Bootable Yes

NAND flash bank[edit | edit source]

On board main storage memory is a 8-bit wide NAND flash connected to the CPU's Raw NAND flash controller. Optionally, it can act as boot peripheral. The following table reports the NAND flash specifications:

CPU connection Raw NAND flash controller
Page size 512 byte, 2 kbyte or 4 kbyte
Size min 128 MB
Size max 2 GB
Width 8 bit
Chip select NANDF_CS0
Bootable Yes

Memory map[edit | edit source]

For detailed information, please refer to chapter 2 “Memory Maps” of the i.MX Applications Processor Reference Manual.

Power supply unit[edit | edit source]

Axel Lite embeds all the elements required for powering the unit, therefore power sequencing is self-contained and simplified. Nevertheless, power must be provided from carrier board, and therefore users should be aware of the ranges power supply can assume as well as all other parameters.

CPU module connector[edit | edit source]

All interface signals Axel Lite provides are routed through SODIMM DDR3 204 pin (named J2). The dedicated carrier board must mount the mating connector and connect the desired peripheral interfaces according to Axel Lite pinout specifications.