MCIMX286CVM4B Freescale Semiconductor, MCIMX286CVM4B Datasheet - Page 12

• Manufacturer Part Number: MCIMX286CVM4B
• Description: IC MPU I.MX286 289MAPBGA
• Manufacturer: Freescale Semiconductor
• Series: i.MX28r

Specifications of MCIMX286CVM4B

• Core Processor: ARM9
• Core Size: 32-Bit
• Speed: 454MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, MMC, SmartCard, SPI, SSI, UART/USART, USB OTG
• Peripherals: DMA, I²S, LCD, POR, PWM, WDT
• Program Memory Size: 128KB (32K x 32)
• Program Memory Type: Mask ROM
• Ram Size: 32K x 32
• Voltage - Supply (vcc/vdd): 1.25 V ~ 5.25 V
• Data Converters: A/D 17x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 289-LFBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of I /o: -
• Eeprom Size: -
• Lead Free Status / Rohs Status: Compliant

SD/MMC/SDIO Card and SPI interfaces
Another good example layout that can be followed is the i.MX28 EVK (evaluation kit) PCB. The PCB
layout source files can be downloaded from the Freescale i.MX28 support webpage. The image below
shows the bottom layer routing of the DDR2 interface. The key item to notice is that all the DDR2 traces
are routed entirely above a solid ground plane (green background) and do not cross any plane splits or other
traces.
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This SDIO and SPI interfaces are serial data in/out interfaces. The SDIO interface consists of clock and
command signal lines and up to 8 data lines. The SPI interface consists of a clock line and up to 4 data
lines (for quad I/O SPI). These interfaces can be high speed, 50MHz or higher, and double data rate for the
eMMC4.4 standard. Because of this, is it important to follow these layout guidelines.
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SD/MMC/SDIO Card and SPI interfaces
Trace capacitance should be minimized.
Avoid crossing plane splits as this will degrade signal integrity and increase radiated emissions.
Trace length matching may be beneficial in some cases where the trace length routing is long (>3
inches).
i.MX28 Layout and Design Guidelines, Rev. 0
Freescale Semiconductor