ZHCSIM5F December 2016 – July 2018 AM5746 , AM5748 , AM5749
ADVANCE INFORMATION for pre-production products; subject to change without notice.
ddrx_vref0 (VREF) is used as a reference by the input buffers of the DDR3 memories as well as the processor. VREF is intended to be half the DDR3 power supply voltage and is typically generated with the DDR3 VDDS and VTT power supply. It should be routed as a nominal 20-mil wide trace with 0.1 µF bypass capacitors near each device connection. Narrowing of VREF is allowed to accommodate routing congestion.