In 1989 Japan granted Texas Instruments a patent for the first semiconductor integrated circuit according this New York Times article: https://www.nytimes.com/1989/11/24/business/japan-grip-still-seen-on-patents.html
Texas Instruments said late Tuesday that the Japanese Patent Office had awarded it a patent for its basic integrated circuit. The company had sought the patent since Feb. 6, 1960. A Potential Windfall
The protection covers all computer chips sold in Japan, dating from Oct. 30, when the patent was granted, through Nov. 27, 2001.
In May, the Bush Administration placed Japan on a ''watch list'' of 17 countries that it accused of denying effective patent protection for American inventions and other intellectual property. If those countries do not approve patent applications within specified periods, they will become subject to trade sanctions.
Texas Instruments said new patent agreements with Japanese chip makers would not take effect until 1991.
See also Thirty-year wait for microchip patent pays off (NewScientist 2 December 1989) and Protecting American Intellectual Property in Japan (Santa Clara High Technology Law Journal, January 1994) for more detail about the above.
There was a 1994 agreement as explained in Reform of Patent System in Japan and Challenges:
Under the U.S.-Japan agreement in 1994, which resulted from the IPR policy dialogue in the framework of structural impediments initiative, both governments agreed to make important policy changes. In 1994, the Japanese government switched from the pre-grant opposition system to the post-grant opposition system. It also pledged not to invoke compulsory licensing to resolve a blocking relationship unless it was for the purpose of correcting anticompetitive conduct or for public or noncommercial use. Furthermore, it expanded the fast track system of patent examination to allow an applicant with an application to a foreign patent office to enjoy a fast track too. The U.S. government in turn pledged to introduce an early disclosure system for patent applications and a re-examination system and to continue refraining from the use of compulsory licensing.
In conclusion there was no bilateral 1989 agreement, but Japan was pressured by the US by listing Japan as a "watch list" country using special 301 provisions of Omnibus Trade and Competitiveness Act.