Schematics

Configuration

  • CPU configuration is written on schematics (DDR speed, CPU frequency, Ratios, L2 cache…)
  • If there are free GPIO, plan to use them as configuration or board identification inputs using pull up or pull down.

JTAG

  • Check JTAG signals are correctly connected to CPU
  • Check JTAG SReset signal is correctly connected to system reset
  • Check if JTAG SRST and TRST needs pull up resistors
  • If multiples TMS signals are available on CPU, use shunt resistor to be able to change easily

Check following page for more details JTAG

RAM

Check DRAM instructions : Schematics

NAND

  • NAND pins are connected to CPU capable nand pins
  • NAND WP pin is pulled correctly
  • NAND RDY signal has correct pull up
  • If NAND is a boot device, check that configuration is correct

SPI

  • SPI pins are connected to CPU capable nand pins
  • If SPI is a boot device, check that configuration is correct

PCI Express

  • Check calibration resistors value
  • Check if CLKREQ is correctly connected
  • Check that there is a serial capacitor on each RX/TX line signal (100nF/0402)
  • Check that there is a 50 Ohm pulldown resistor on each Clock signal
  • Check that clock frequency is 100MHz

Ethernet

  • Check that ethernet signals are connected to hardware capable pins
  • Check signal voltage level
  • Check that GE_MDIO has a 2kOhm pullup resistor

RGMII

  • In RGMII, check if there is a need of delay function

SGMII

  • In SGMII, check that there is a 10nF serial capacitor on TX and RX signals
  • Check that SGMII signals are connected to the right Serdes port

SATA

  • Check SATA calibration resistor value
  • Check that SATA signals are connected to hardware capable pins
  • Check that there is a 10nF serial capacitor on each TX and RX SATA signal

USB

I²C

  • Check that there is a 4.7KOhms pull up resistor on Clock and DATA signals
  • List all used bus address and check that here is on conflict
  • Check voltage levels

Reset

  • Check that there is a pull up resistor on reset signal
  • Check that reset meets timing requriements
  • Bookmark at
  • Bookmark "Schematics" at del.icio.us
  • Bookmark "Schematics" at Digg
  • Bookmark "Schematics" at blogmarks
  • Bookmark "Schematics" at Google
  • Bookmark "Schematics" at Facebook
  • Bookmark "Schematics" at Twitter