JAJSDY9B April 2015 – April 2019 AM3358-EP
PRODUCTION DATA.
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 7-42. This region should encompass all DDR2 circuitry and the region size varies with component placement and DDR2 routing. Additional clearances required for the keepout region are shown in Table 7-49. Non-DDR2 signals must not be routed on the same signal layer as DDR2 signals 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 or VDDS_DDR power plane in this region. In addition, the VDDS_DDR power plane should cover the entire keepout region.