1. SATA.
The i.MX53 SATA also integrates a temperature sensor.
The temperature can be read by the CPU, and frequency may be scaled-up or
scaled-down accordingly.
In case the SATA, including the temperature sensor, is not needed :
- the VP and VPH should be grounded ;
- the rest of the ports both inputs and outputs could be left floating
(SATA_REFCLKM , SATA_REFCLKP , SATA_REXT , SATA_RXM , SATA_RXP , SATA_TXM)
When only temperature sensor is used:
- VP and VPH still need to be connected to 1.3V and 2.5V respectively.
- Reference clock input frequency is not important but needs to be within the
specified range: 25Mhz to 156.25Mhz.
2. TVE.
If not using TVE the module, the TVDAC_DHVDD and TVDAC_AHVDDRGB can remain floating.
If only the GPIO pads in TVDAC_AHVDDRGB domain are in use, the supplies can be
set to GPIO pad voltage range (1.65 V to 3.1 V). TVDAC_VREF should be left free, if TVE is
not used.
If TV OUT is not used, float the COMP contact and ensure the DACs are powered down by software.
3. LVDS.
If LVDS is not used, LVDS_BG_RES input can be left free.
To be fully on safe side - connect NVCC_LVDS_BG to a 2.5 V supply though a series 49.9 Ohm resistor.
Mount a 0.01 uF decoupling capacitor near the NVCC_LVDS_BG BGA contact.
4. General considerations.
As for recommendations regarding some unused features of the i.MX53,
also please use the Design Checklist in i.MX53 System Development Users Guide.
http://cache.freescale.com/files/32bit/doc/user_guide/MX53UG.pdf
Next are general DIGITAL INPUT RECOMMENDATIONS.
For unused inputs that are mux-ed with GPIO :
- Configure pins to be GPIO.
- Configure pins to be inputs.
- Make sure the internal pull up resistors are enabled.
For unused inputs that are not mux-ed with GPIO pins :
- Connect each pin with a 10K Ohm resistor to ground.
DIGITAL OUTPUT RECOMMENDATIONS.
Leave the unused output pins floating.
