MCF548x Reference Manual, Rev. 3
6-6 Freescale Semiconductor
Biased exponent (e) 8 11
Fraction (f) 23 52
Total 32 64
Interpretation of Sign
Positive fraction s = 0 s = 0
Negative fraction s = 1 s = 1
Normalized Numbers
Bias of biased exponent +127 (0x7F) +1023 (0x3FF)
Range of biased exponent 0 < e < 255 (0xFF) 0 < e < 2047 (0x7FF)
Range of fraction Zero or Nonzero Zero or Nonzero
Mantissa 1.f 1.f
Relation to representation of real numbers (–1)s × 2e–127 × 1.f (–1)s × 2e–1023 × 1.f
Denormalized Numbers
Biased exponent format minimum 0 (0x00) 0 (0x000)
Bias of biased exponent +126 (0x7E) +1022 (0x3FE)
Range of fraction Nonzero Nonzero
Mantissa 0.f 0.f
Relation to representation of real numbers (–1)s × 2–126 × 0.f (–1)s × 2–1022 × 0.f
Signed Zeros
Biased exponent format minimum 0 (0x00) 0 (0x00)
Mantissa 0.f = 0.0 0.f = 0.0
Signed Infinities
Biased exponent format maximum 255 (0xFF) 2047 (0x7FF)
Mantissa 0.f = 0.0 0.f = 0.0
NANs
Sign Don’t Care 0 or 1
Biased exponent format maximum 255 (0xFF) 2047 (0x7FF)
Fraction Nonzero Nonzero
Representation of Fraction
Nonzero Bit Pattern Created by User
Fraction When Created by FPU
xxxxx…xxxx
11111…1111
xxxxx…xxxx
11111…1111

Table 6-3. Real Format Summary (Continued)

Parameter Single-Precision Double-Precision