Revision # 1.70   Modifications made on March 9, 2009

• The Pad Assignment section was removed.
  　
• The Pad Coordinates section was removed.
  　
• The Package Information section was modified.
  　
• The Product Tape and Reel Specifications section was modified.

Revision # 1.60   Modifications made on August 14, 2008

• The Pad Assignment was modified.
  　
• The Pad Coordinates was modified.
  　
• The Package Information section was modified.
  　
• At The Product Tape and Reel Specifications section, the Carrier Tape Dimensions diagram was modified.

Revision # 1.50   Modifications made on October 1, 2007

• In the Electrical Characteristics table, the Min. value for V_IH2 was modified.

Revision # 1.40   Modifications made on March 4, 2003

• The Pad Assignment and Pad Coordinates sections were modified.
• The Approximate internal connection circuits section was modified.
• Package Information section was added.
• Product Tape and Reel Specifications section was added.

Revision # 1.30   Modifications made on September 5, 2001

• The Pad names were updated.

Revision # 1.20   Modifications made on May 31, 2001

• At the Timing Diagram 2, the units were changed from 8.77ms to 8.77µs, and 26.3ms to 26.3µs.
• The 20/24-pin DIP package were deleted.

Revision # 1.10   Modifications made on March 13, 2001

• HT6221_002/HT6222_002 and all those related to such part numbers were deleted.
• The Customer ROM Code Approved Tables were also deleted.