From Real Time Systems Design And Analysis

7.5.3   Binary Angular Measure

Another type of scaled number is based on the property that adding 180o to any
angle is analogous to taking its two’s complement. This technique, called binary
angular measurement (BAM) works as follows. Consider the LSB of an n-bit
word to be 2n−1 · 180 degrees with the most significant bit (MSB) = 180 degrees.
The range of any angle θ represented this way is 0 ≤ θ ≤ 360 − 180 · 2-(n−1)
degrees. A 16-bit BAM word is shown in Figure 7.6. For more accuracy, BAM
can be extended to two more words. Each n-bit word has a maximum value of


with granularity


Consider the 16-bit BAM word:

 0000 0000 10100 110

Its binary angular measurement is 166 · 180o · 2−15 = 0.9118o.

Figure 7.6 A 16-bit binary angular measurement word [Laplante03c].

BAM can be added and subtracted together and multiplied and divided by
constants as if they were unsigned integers, and converted at the last stage to
produce floating-point results. It is easy to show that the overflow condition for
BAM numbers presents no problem as the angle simply wraps around to 0. BAM
is frequently used in navigation software, robotic control, and in conjunction with
digitizing imaging devices.


© 2004

Products & Services
PCMCIA Memory Cards
PCMCIA memory cards and storage cards are used to add memory (RAM, SRAM, Flash, etc.) and/or storage capacity (hard disks, CD-ROM, etc.) to computers.
Memory Modules
Memory modules are computer chips used to add memory to a computer.
CPU Cards and Modules
CPU cards and modules are computer boards that contain the central processing unit (CPU) of a computer.
CompactPCI and PXI Bus Interfaces
Compact PCI bus interfaces and PXI bus interfaces allow the CompactPCI / PXI system to communicate with other devices or systems.
VME, VPX, and VXI Bus Interfaces and Adapters
VME, VPX and VXI bus interfaces and adapters allow VME, VPX, and VPI buses to communicate with other types of computer systems and devices.

Topics of Interest

7.5.4   Look-Up Tables Another variation of the scaled-number concept uses a stored table of function values at fixed intervals. Such a table, called a look-up table, allows for the computation...

9.5.2   Burst Error Locating (BlEL) Codes By using the concept of the frame, we define a new class of burst error locating codes. Definition 9.4 A code is called an l-burst error locating code if...

9.5.4   Decoding Procedure Single-bit error correction is easily executed. If the syndrome of the received word is equal to one column vector of the parity-check matrix H, the corresponding bit...

3 SUCCESSIVE APPROXIMATIONS The successive approximations algorithm allows to find quickly a digital value by dichotomic search. By performing a sequence of comparisons, it converges to the desired...

In this chapter we extend the analysis in Chapter 5 to systems with two or more poles and one or more zeros. Such systems are commonly referred to as higher order systems. In computing systems,...