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Mazda Connect CMU Hardware Specs (Gen 6 / i.MX6)

The CMU (Connectivity Master Unit) is the computer behind every Gen 6 Mazda Connect head unit. Hardware is by Visteon; the software stack was developed by Johnson Controls (JCI). The same unit shipped across Mazda’s Gen 6 lineup, with source-backed North American v74.00.324A vehicles spanning 2014–2023 depending on model. Its internal designation is MAZDA_GEN_65_CMU (community shorthand: “CMU 150”). For the sourced model-and-year list, see Supported vehicles.

Source basis: component IDs, connector pins, and storage layout are cross-checked against silverchris/mazda-cmu-documentation. SoC capabilities are from NXP i.MX6D product documentation. Firmware-specific names such as MAZDA_GEN_65_CMU, device nodes, and VIP message counts come from local firmware/rootfs analysis.

  • NXP i.MX6D — dual-core ARM Cortex-A9, ARMv7. NXP publishes this family as the i.MX 6Dual application processor line.
  • Clock: 675 MHz (measured at runtime; NXP rates the i.MX6D at up to 1.2 GHz, so the CMU runs downclocked)
  • RAM: 1 GB DDR3 physical — 746 MB Linux-visible (258 MB reserved for GPU/VPU)
  • Secure boot: i.MX6 HABv4 exists in hardware but is not enabled.

This is the constraint that defines the whole platform. Two Cortex-A9 cores at 675 MHz with under 750 MB of usable RAM is the budget the entire infotainment stack runs inside, which is why startup time and service count matter so much — see Boot chain and Services.

MediumSizeUse
NAND1 GBRoot filesystem. Datalight FlashFX / relfs FTL.
eMMC (Micron)4 GBUser data, navigation, logs.
SPI-NOR (Macronix)8 MBBootloader, failsafe image, persistent config.

The SPI-NOR holds the bootloader and a failsafe image, which is what makes the unit recoverable after a bad flash — see Boot chain. For the full partition layout, see Filesystem internals.

  • Renesas R5F35MCEJFB — M16C family, 16-bit
  • RTOS: MR30
  • Role: bridges the vehicle CAN and LIN buses to the application SoC

The App SoC talks to the VIP MCU over an SPI bus. The VIP exposes a subset of vehicle CAN IDs to the application processor as read-only telemetry; public documentation confirms its CAN/LIN bridge role. The application side never drives the vehicle buses directly — it sees what the VIP forwards.

  • WiFi: TI WL1285Q (wl12xx driver, SDIO interface)
  • Bluetooth: Murata LBEE6Z2U0C-584
  • u-blox NEO-M8L automotive dead-reckoning receiver
  • High navigation rate (HNR) output up to 30 Hz via sensor fusion (GNSS + gyro + accelerometer + wheel ticks)
  • Hardware documentation also references an STMicro STA8088F — likely a secondary receiver or a variant revision rather than a confirmed second unit on every board.
  • NXP TJA1043 (HS-CAN, bus-selective wake)
  • NXP TJA1042

Two display variants share the same CMU hardware:

VariantSizeResolutionInputNotes
Standard7-inch800×480Capacitive touch + commander knobMost models
Widescreen8.8-inch1280×480Commander knob only (non-touch)Higher-trim CX-5, CX-9

Both connect to the CMU over a Maxim MAX9265 serializer link. Standard display part numbers: K123-61-1J0A/B/C (various revisions). The widescreen unit is knob-only — the 8.8-inch panel has no touch digitizer, which is a hardware fact, not a firmware setting.