| 摘要 |
PURPOSE:To make it possible to use the circuit for the system having a different representation format of the exponential part, as well, by deciding the generation of overflow and underflow of the exponential part, without increasing the extended bit and the mode indicating control signal, or changing the control status at the time of operation. CONSTITUTION:The FF6 and the interruption register 7 are provided on the trigger chip 2, this FF6 and the register 7 are connected to the handler 5 of the byte adder chip 1, and the byte adder 3 and the operation result register 4 are connected to this handler 5. The operation indicating control signals EXPiNC, EXPDEC and the mode indicating control signal are provided to this handler 5 from the outside, and the flow indicating control signals EXO, EXU are provided from the FF6. When overflow and/or underflow has occurred, the interruption is executed to the program through the register 7, and when the interruption cannot be executed by the mask condition at the time of underflow, a PROCONTROL signal is sent to the register 4, the contents of the register 4 are made zero forcibly, and it is decided that overflow or underflow has occurred in the exponential part. |
