Machine Trap Value Register (mtval): 0x343

The mtval register is a 32-bit register. When a trap is taken into M-mode, mtval is either set to zero or written with exception-specific information to assist software in handling the trap. Otherwise, mtval is never written by the implementation, though it may be explicitly written by software. The hardware platform will specify which exceptions must set mtval informatively and which may unconditionally set it to zero.

31 0
mtval
Bits Field Description Single/Multi Core w/FPU w/MMU
0-31 mtval Machine trap value register bit. Read/Write Read/Write Read/Write