Test Equipment, Debuggers, Development Systems

Test Equipment

Name Cost Pros Cons

Logic Probe $2-$20 Handy, cheap Only sees one line,
Does not record in real time (may have a pulse LED to show AC signals)

Logic Analizer $200-$2000
(speed) Can record events in real time.
Some can disassemble machine code to provide more readable diagnostics. May not see the signal the same way the circuit under test sees it due to differing level sensitivities or differences in timing of the sampleing.

Oscilliscope
(Analog, with trigger) $300-$5000
(depending on speed) Can view composits of events (detected by external trigger circuit) in real time.
Displays the entire signal including the exact voltage and timing (if the scope is faster and more accurate than the signal). Really shows what the circuit is seeing (probably). Non-recording models do not show individual signals but instead display a composit of many copies of the same signal one on top of the next. Isolated incidents may be missed.
Can display only one or two signals (called channels or traces) at a time.
If the signal changes fast enough, the 'scope may miss it.
Doesn't know how the circuit will respond to the signal.

Oscilliscope
(Digital) $1000-$50,000
(depending on speed) Can record and view individual events (detected by external trigger circuit) in real time.
Displays the entire signal including the exact voltage and timing. Really shows what the circuit is seeing. Can display only one or two signals (called channels or traces) at a time.
If the signal changes fast enough, the 'scope may miss it.
Doesn't know how the circuit will respond to the signal.

Mixed Mode DSO $1000-$100,000
(depending on speed) Combination of a Digital Ocilliscope with a Logic Analizer. All the advantages... If the signal changes fast enough, the 'scope may miss it.
Doesn't know how the circuit will respond to the signal.

In Circuit Emulator (I.C.E.) $2000-$100,000
(except for Scenix) Should allow recording from the point of view of the circuit (so the signal levels and timing dont matter). What you see is what it got.
Allows single step and easy setup of breakpoints to stop excecution when a set condition occurs. Just tells you how the processor saw the signal, not why the signal was seen that way (Was there a spike? Was the signal weak? Is the timing wrong? etc..)
The emulator may respond differently than the production component (screwed up in actual operation, works fine when you plug in the emulator.. hah-hah)
Some cheap emulators will not correctly support external events like IO port signals and interrupts.

Simulators Free to $1000 Allows testing of basic code and ideas without even needing to have the device.
Can show everything including. long list. Not real time, not real (simulations are doomed to succeed). Will not catch all the Gotchas.

Name	Cost	Pros	Cons
Logic Probe	$2-$20	Handy, cheap	Only sees one line, Does not record in real time (may have a pulse LED to show AC signals)
Logic Analizer	$200-$2000 (speed)	Can record events in real time. Some can disassemble machine code to provide more readable diagnostics.	May not see the signal the same way the circuit under test sees it due to differing level sensitivities or differences in timing of the sampleing.
Oscilliscope (Analog, with trigger)	$300-$5000 (depending on speed)	Can view composits of events (detected by external trigger circuit) in real time. Displays the entire signal including the exact voltage and timing (if the scope is faster and more accurate than the signal). Really shows what the circuit is seeing (probably).	Non-recording models do not show individual signals but instead display a composit of many copies of the same signal one on top of the next. Isolated incidents may be missed. Can display only one or two signals (called channels or traces) at a time. If the signal changes fast enough, the 'scope may miss it. Doesn't know how the circuit will respond to the signal.
Oscilliscope (Digital)	$1000-$50,000 (depending on speed)	Can record and view individual events (detected by external trigger circuit) in real time. Displays the entire signal including the exact voltage and timing. Really shows what the circuit is seeing.	Can display only one or two signals (called channels or traces) at a time. If the signal changes fast enough, the 'scope may miss it. Doesn't know how the circuit will respond to the signal.
Mixed Mode DSO	$1000-$100,000 (depending on speed)	Combination of a Digital Ocilliscope with a Logic Analizer. All the advantages...	If the signal changes fast enough, the 'scope may miss it. Doesn't know how the circuit will respond to the signal.
In Circuit Emulator (I.C.E.)	$2000-$100,000 (except for Scenix)	Should allow recording from the point of view of the circuit (so the signal levels and timing dont matter). What you see is what it got. Allows single step and easy setup of breakpoints to stop excecution when a set condition occurs.	Just tells you how the processor saw the signal, not why the signal was seen that way (Was there a spike? Was the signal weak? Is the timing wrong? etc..) The emulator may respond differently than the production component (screwed up in actual operation, works fine when you plug in the emulator.. hah-hah) Some cheap emulators will not correctly support external events like IO port signals and interrupts.
Simulators	Free to $1000	Allows testing of basic code and ideas without even needing to have the device. Can show everything including.	long list. Not real time, not real (simulations are doomed to succeed). Will not catch all the Gotchas.