Circuit Board Reference Manual

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.