DSP program control port, program step execution control bit 
 (= 0: not executed / = 1: executed)  

 DSP program control port, program execution control bit 
 (= 0: not executed / = 1: executed)  

 V-blank-IN interrupt mask bit  

 V-blank-OUT interrupt mask bit  

 H-blank-IN interrupt mask bit  

 Timer 0 interrupt mask bit  

 Timer 1 interrupt mask bit  

 DSP end interrupt mask bit  

 Sound request interrupt mask bit  

 SMPC interrupt mask bit  

 PAD interrupt mask bit  

 Level 2-DMA end interrupt mask bit  

 Level 1-DMA end interrupt mask bit  

 Level 0-DMA end interrupt mask bit  

 DMA illegal interrupt mask bit  

 Sprite drawing end interrupt mask bit  

 A-Bus interrupt mask bit  

 V-Blank-IN Interrupt Status Bit  

 V-Blank-OUT Interrupt Status Bit  

 H-blank-IN interrupt status bit  

 Timer 0 interrupt status bit  

 Timer 1 interrupt status bit  

 DSP end interrupt status bit  

 Sound request interrupt status bit  

 SMPC interrupt status bit  

 PAD interrupt status bit  

 Level 2-DMA end interrupt status bit  

 Level 1-DMA end interrupt status bit  

 Level 0-DMA end interrupt status bit  

 DMA illegal interrupt status bit  

 Sprite drawing end interrupt status bit  

 DSP program control port, program counter load enable bit 
 (= 0: not executed / = 1: executed)  

 DSP program control port, temporary stop release flag during program execution 
 (= 0: not executed / = 1: executed)  

 SD RAM selection bit (= 0: 2Mbit × 2 / = 1: 4Mbit × 2)  

 DSP program control port, sign flag