An intruder detection system for a large house has four sensors. An 8-bit memory location stores the output from each sensor in its own bit position.
The bit value for each sensor shows:
– 1 – The sensor has been triggered
– 0 – The sensor has not been triggered

The bit positions are used as follows:

The output from the intruder detection system is a loud alarm.
a) i) State the name of the type of system to which intruder detection systems belong.
ii) Justify your answer to part i).
b) Name two sensors that could be used in this intruder detection system.
Give a reason for your choice.
c) The intruder system is set up so that the alarm will only sound if two or more sensors have been triggered. An assembly language program has been written to process the contents of the memory location.

This table shows part of the instruction set for the processor used.

Part of the assembly code is:

i) Copy the table below and dry run the assembly language code.
Start at LOOP and finish when EXIT is reached.

ii) The operand for the instruction labelled TEST is missing.
State the missing operand.
iii) The intruder detection system is improved and now has eight sensors. One instruction in the assembly language code will need to be amended.
Identify this instruction. Write the amended instruction.

Transcribed Image Text:

Not used Sensor 4 Sensor 3 Sensor 2 Sensor 1