ZHCS488K October 2011 – December 2018 AM3351 , AM3352 , AM3354 , AM3356 , AM3357 , AM3358 , AM3359
PRODUCTION DATA.
Like DDR_VREF, the nominal value of the VTT supply is half the DDR3 supply voltage. Unlike DDR_VREF, VTT is expected to source and sink current, specifically the termination current for the ADDR_CTRL net class Thevinen terminators. VTT is needed at the end of the address bus and it should be routed as a power sub-plane. VTT should be bypassed near the terminator resistors.