4
Operation
GPS/GLONASS Receiver User Manual Rev 1
37
The following table describes the format types used in the description of binary logs.
Each byte within an int has its own address, and the smallest of the addresses is the address of the int. The byte at
this lowest address contains the eight least significant bits of the doubleword, while the byte at the highest address
contains the eight most significant bits. The following illustration shows the arrangement of bytes within words
and doublewords. Similarly the bits of a "double" type are stored least significant byte first. This is the same data
format used by IBM PC computers.
Type
Size
(bytes)
Size
(bits)
Description
char
1
8
The char type is used to store the integer value of a member of the representable character
set. That integer value is the ASCII code corresponding to the specified character.
int
4
32
The size of a signed or unsigned int item is the standard size of an integer on a particular
machine. On a 32-bit processor (such as the NovAtel GPSCard), the int type is 32 bits, or 4
bytes. The int types all represent signed values unless specified otherwise. Signed integers
are represented in two’s-complement form. The most-significant bit holds the sign: 1 for
negative, 0 for positive and zero.
double
8
64
The double type contains 64 bits: 1 for sign, 11 for the exponent, and 52 for the mantissa. Its
range is ±1.7E308 with at least 15 digits of precision.
float
4
32
The float type contains 32 bits: 1 for the sign, 8 for the exponent, and 23 for the mantissa. Its
range is ±3.4E38 with at least 7 digits of precision.
7
0
address n
31
23
15
7
0
62
55
47
51
39
31
23
15
7
n+3
n+2
n+1
address n
complement
63
52
n+7
n+6
n+5
n+4
n+3
n+2
n+1
30
n+3
23
22
15
7
0
n+2
n+1
address n
23-bits mantissa
52-bits mantissa
two’s
address n
S
S
char
int
31
Biased
Exponent
Biased
Exponent
double
float
0
0