MCF548x Reference Manual, Rev. 3
6-8 Freescale Semiconductor

The user can read or write to FPCR using FMOVE or FRESTORE. A processor reset or a restore operation

of the null state clears the FPCR. When this register is cleared, the FPU never generates exceptions.

Table 6-4 describes FPCR fields.

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
R0 0 0 000000000000 0
W
Reset0 0 0 000000000000 0
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Exception Enable Byte (EE) Mode Control Byte (MC)
R BSUN INAN OPERR OVFL UNFL DZ INEX IDE 0 PREC RND 0 0 0 0
W
Reset0 0 0 000000000000 0
Reg
Addr
CPU + 0x824

Figure 6-9. Floating-Point Control Register (FPCR)

Table 6-4. FPCR Field Descriptions

Bits Field Description
31–16 Reserved, should be cleared.
15 BSUN Branch set on unordered
14 INAN Input not-a-number
13 OPERR Operand error
12 OVFL Overflow
11 UNFL Underflow
10 DZ Divide by zero
9 INEX Inexact operation
8 IDE Input denormalized
7 Reserved, should be cleared.
6 PREC Rounding precision
0 Double (D)
1Single (S)
5–4 RND Rounding mode
00 To nearest (RN)
01 To zero (RZ)
10 To minus infinity (RM)
11 To plus infinity (RP)
3–0 Reserved, should be cleared.