Wikipedia[0] does have it as the SM83

[0] https://en.wikipedia.org/wiki/Game_Boy_Advance - "Manufactured by the Sharp Corporation, the SoC contains two processors: the ARM7TDMI running at a clock rate of 16.776 megahertz (MHz) for GBA games, and the Sharp SM83 running at 4.194 MHz or 8.389 MHz for backward compatibility with Game Boy and Game Boy Color games."