Tokyo stocks were mixed Thursday morning, as the market was pressured by weak chip-related shares tracking falls in their U.S. counterparts, while rising oil prices lifted energy issues to limit losses. The 225-issue Nikkei Stock Average fell 70.75 points, or 0.18 percent, from Wednesday to 38,625.22. The broader Topix index was up 0.15 point, or 0.01 percent, at 2,648.66. The U.S. dollar moved narrowly in the upper 147 yen range in Tokyo, as participants refrained from active trading ahead of policy meetings by central banks in Japan and the United States, dealers said. At noon, the dollar fe…