I was looking through a datasheet, when I noticed this sentence:
TSOP package is suitable for cards, and reverse type TSOP is also provided.
What is a "reverse type" TSOP? I am familiar with TSOP packages.
The difference is shown on page 3 of the datasheet you linked to. It is not a difference in package, but a difference in pin arrangement. Compare the pins between the HM628128ALT and the HM628128ALR -- the pin functions are reflected. Page 2 indicates that the ...ALT version is "normal type" and the ...ALR version is "reverse type".