Сопроцессор MIPS1, используется для обработки аппаратных исключений.

• $0 - N/A
• $1 - N/A
• $2 - N/A
• $3 - BPC - Breakpoint on execute (R/W)
• $4 - N/A
• $5 - BDA - Breakpoint on data access (R/W)
• $6 - JUMPDEST - Randomly memorized jump address (R)
• $7 - DCIC - Breakpoint control (R/W)
• $8 - BadVaddr - Bad Virtual Address (R)
• $9 - BDAM - Data Access breakpoint mask (R/W)
• $10 - N/A
• $11 - BPCM - Execute breakpoint mask (R/W)
• $12 - SR - System status register (R/W)
• $13 - CAUSE - (R) Describes the most recently recognised exception
• $14 - EPC - Return Address from Trap (R)
• $15 - PRID - Processor ID (R)
• $16-31 - Garbage
• $32-63 - N/A