Register Model
e200z3 Power Architecture Core Reference Manual, Rev. 2
2-18
Freescale Semiconductor
47
MODE
Embedded floating-point operating mode.
0 Default hardware results operating mode. The e200z3 supports only mode 0.
1 IEEE754 hardware results operating mode (not supported by the e200z3).
Controls the operating mode of the embedded floating-point APU. Software should read the value of this bit
after writing it to determine whether the implementation supports the selected mode. Implementations return
the value written if the selected mode is supported. Otherwise, the value read indicates the
hardware-supported mode.
48
SOV
Summary integer overflow. Set when an instruction sets OV. SOV remains set until it is cleared by an
mtspr
specifying SPEFSCR.
49
OV
Integer overflow. Set whenever an integer or fractional SPE instruction signals an overflow in the low element
result.
50
FG
Embedded floating-point guard bit. Used by the floating-point round exception handler. Cleared if a
floating-point data exception occurs for the low elements. Corresponds to the low element result.
51
FX
Embedded floating-point sticky bit. For use by the floating-point round exception handler. FX is cleared if a
floating-point data exception occurs for the low elements. FX corresponds to the low element result.
52
FINV
Embedded floating-point invalid operation/input error. In mode 0, FINV is set if the A or B low element operand
of a floating-point instruction is Infinity, NaN, or Denorm, or if the operation is a divide and the low element
dividend and divisor are both 0. In mode 1, FINV is set on an IEEE754 invalid operation (IEEE754-1985
sec7.1) in the low element.
53
FDBZ
Embedded floating-point divide by zero. Set when a floating-point divide instruction executes with a low
element divisor of 0 and the low element dividend is a finite non-zero number.
54
FUNF
Embedded floating-point underflow. Set when the execution of a floating-point instruction results in an
underflow in the low element.
55
FOVF
Embedded floating-point overflow. Set when the execution of a floating-point instruction results in an overflow
in the low element.
56
—
Reserved, should be cleared.
57
FINXE
Embedded floating-point inexact exception enable. If the exception is enabled, a floating-point round
exception is taken under one of the following conditions:
• For both elements, the result of a floating-point instruction does not result in overflow or underflow, and the
result for either element is inexact (FG | FX = 1.
• FGH | FXH =1)
• The result of a floating-point instruction does result in overflow (FOVF=1 or FOVFH=1) for either element,
but floating-point overflow exceptions are disabled (FOVFE=0)
• The result of a floating-point instruction results in underflow (FUNF=1 or FUNFH=1), but floating-point
underflow exceptions are disabled (FUNFE=0), and no floating-point data exception occurs.
0 Exception disabled.
1 Exception enabled.
58
FINVE
Embedded floating-point invalid operation/input error exception enable.
0 Exception disabled.
1 Exception enabled. A floating-point data exception is taken if FINV or FINVH is set by a floating-point
instruction.
59
FDBZE Embedded floating-point divide by zero exception enable.
0 Exception disabled.
1 Exception enabled. A floating-point data exception is taken if FDBZ or FDBZH is set by a floating-point
instruction.
Table 2-9. SPEFSCR Field Descriptions (continued)
Bits
Name
Description