Environmental Engineering Reference
In-Depth Information
Figure 2. Program flow for a fire fighting robot. (a) Inefficient program. (b) Efficient program
FUTURE RESEARCH DIRECTIONS
When represented as a binary number a node
holding a bit 1 should be allowed to hold a bit 1.
Suppose in a particular application the data are
read from consecutive memory locations. These
memory addresses shall be placed in the address
bus one after another. Table 1 gives the sequence of
numbers tabulated as binary address with natural
encoding. We can observe that, the 1-0 transition
is at one place when 2
nd
address is placed at the
address bus. But for the third address there are
changes for two bit positions and dynamic power
dissipation gets doubled. To minimize this power
dissipation gray encoding (Yeap, 1998) given in
the last column may be adopted. In this encoding
technique number of transitions for consecutive
address is always 1.
If we study the product family of MSP430 we
observe that, recent versions are tailor made for
a particular application class. If that application
needs to monitor humidity a humidity sensor shall
be included in the chip and a single chip solution
shall be provided.
A new idea has come up for dynamic power
minimization for CMOS circuits (Weste, 1993)
used in microcontroller. In a CMOS circuit if
voltage at any node makes a transition from high
to low or low to high the capacitor attached to the
node discharges or charges respectively through a
resistor. The current through the resistor generates
heat and power loss takes place. For this reason
the voltage change at a node should be minimized.
