3.3.4.4 OVFL_CARRYOUT
(Ask a Question)Each Math block has an overflow signal, OVFL_CARRYOUT. This signal indicates any overflow from the addition operation performed by the adder. This signal is also used to extend the adder data widths from the existing 48 bits using fabric resources. It is also used to implement saturation capabilities. Saturation refers to catching an overflow condition and replacing the output with either the maximum (most positive) or minimum (most negative) value that can be represented.
| OVFL_CARRYOUT_SEL | OVFL_CARRYOUT | Description |
|---|---|---|
| 0 | (SUM[49] XOR SUM[48]) OR (SUM[48] XOR SUM[47]) | True, if overflow or underflow occurred. |
| 1 | C[47] XOR E[47] XOR SUM[48] | A signal that can be used to extend the final adder in the fabric. |