User`s guide

2 Using the IQmath Library
2-6
to 7 bits with sign extension, the number becomes 1111101 and the value of the
number remains the same.
One bit is the designated sign bit, forcing m to be -2:
m+n+1 = -2+17+1 = 16 bits total
Therefore this number is expressed as
Q-2.17
In the Fixed-Point Blockset, this data type is expressed as
sfix16_En17
In the Filter Design Toolbox, this data type is expressed as
[16 17]
Example — Q17.-2
Consider a signed 16-bit number with a scaling of 2^(2) or 4. This means that
the binary point is implied to be 2 bits to the right of the 16 bits, or that there
are n = -2 bits to the right of the binary point. One bit must be the sign bit,
thereby forcing m to be 17:
m+n+1 = 17+(-2)+1 = 16
Therefore this number is expressed as
Q17.-2
In the Fixed-Point Blockset, this data type is expressed as
sfix16_E2
In the Filter Design Toolbox, this data type is expressed as
[16 -2]