Manoel, segue algumas contribuições. Qualquer dúvidas estou a disposição para esclarecer

[mmssouza]

CHANGELOG:

• Implemented round robin schedule.
• Implemented a general check_collission() to eliminate check_fall_collision(), check_right_collision() and check_left_collission().
• Pieces matrices resized to 3x3.
• Improved piece rotation algorithm.
• Added Timer2 int for display refresh.
• Added key_manager() to deal with key reactions outside external interrupts.
• Added game_manager() to implement game as a state machine.
• Implemented Gameover animation inline in game_manager().
• Added timer variable for timming management.
• Instead of disable all interrupts when updating display buffer, disable Timer2 int only.
• Implemented init() routine and moved all initializations into it.
• Changed either hw and sw strategy to handle display colummns.

[ryukinix]

Muito obrigado por dar atenção e contribuir, professor Marcelo!!! Vou olhar aqui com calma as alterações.