SPRS975H August 2016 – February 2020 DRA780 , DRA781 , DRA782 , DRA783 , DRA785 , DRA786 , DRA787 , DRA788
Refer to the PDF data sheet for device specific package drawings
The region of the PCB used for the DDR2 circuitry must be isolated from other signals. The DDR2 keepout region is defined for this purpose and is shown in Figure 7-27. The size of this region varies with the placement and DDR routing. Additional clearances required for the keepout region are shown in Table 7-14.
The region shown in Table 7-14 should encompass all the DDR2 circuitry and varies depending on placement. Non-DDR2 signals should not be routed on the DDR signal layers within the DDR2 keepout region. Non-DDR2 signals may be routed in the region, provided they are routed on layers separated from DDR2 signal layers by a ground layer. No breaks should be allowed in the reference ground layers in this region. In addition, the vdds_ddrx power plane should cover the entire keepout region. Routes for the two DDR interfaces must be separated by at least 4x; the more separation, the better.