PNI TCM - Manual (Page 42)

PNI Sensor Corporation DOC#1014688 r06
TCM User Manual – July 2013 Page 37
7.2 Parameter Formats
Note: Floating-point based parameters conform to ANSIring/IEEE Std 754-1985. Please refer to the
Standard for more information. PNI also recommends refer to the
user’s compiler instructions to
understand how the compiler implements floating-point format.
64-Bit Floating Point (Float64)
The 64-bit float format is given below in big Endian. In little Endian, the bytes are in
reverse order in 4 byte groups. (eg. big Endian: ABCD EFGH; little Endian:
DCBA HGFE).
Exponent S Mantissa
63 62 52 51 0
The value (v) is determined as: “if and only if” 0 < Exponent < 2047, then
v = (-1)*S*2(Exponent-1023)*1.Mantissa
32-Bit Floating Point (Float32)
Shown below is the 32-bit float format in big Endian. In little Endian format, the 4
bytes are in reverse order, with LSB first.
Exponent S Mantissa
3130 23 22 0
The value (v) is determined as: “if and only if” 0 < Exponent < 255, then
v = (-1)*S*2(Exponent-127)*1.Mantissa
Signed 32-Bit Integer (SInt32)
SInt32-based parameters are signed 32-bit numbers, in 2’s compliment. Bit 31
represents the sign of the value, where 0=positive and 1=negative.
msb
31 24 23 16 15 8
lsb
7 0
Big Endian
lsb
7 0 15 8 23 16
msb
31 24
Little Endian