9.2  x87 Status Word

The x87 status word, FSW[15:0], is used by hardware to record exceptional and other conditions that arise during the execution of x87 instructions. It also contains a pointer to the top of the x87 data register stack. The status word bits, as shown in Figure 9.2, are as follows:

Figure 9.2: x87 Status Word

David Russinoff 2017-08-01