A bond-out processor is an
emulation processor that takes the place of the
microcontroller
A microcontroller (MCU for ''microcontroller unit'', often also MC, UC, or μC) is a small computer on a single VLSI integrated circuit (IC) chip. A microcontroller contains one or more CPUs ( processor cores) along with memory and programma ...
or
microprocessor
A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...
in the target board while an application is being developed and/or debugged.
Bond-out processors have internal signals and bus brought out to external pins. The term bond-out derives from connecting (or bonding) the emulation circuitry to these external pins. These devices are designed to be used within an
in-circuit emulator
In-circuit emulation (ICE) is the use of a hardware device or in-circuit emulator used to debug the software of an embedded system. It operates by using a processor with the additional ability to support debugging operations, as well as to ca ...
and are not typically used in any other kind of system.
Bond-out pins were marked as no-connects in the first devices produced by
Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the devel ...
, and were usually not connected to anything on the ordinary production silicon. Later bond-out versions of the microprocessor were produced in a bigger package to provide more signals and functionality.
Bond-out processors provides capabilities far beyond those of a simple ROM monitor. A ROM monitor is a firmware program that runs instead of the application code and provides a connection to a host computer to carry out debugging functions. In general the ROM monitor uses part of the processor resources and shares the memory with the user code.
Bond-out processors can handle complex
breakpoints
In software development, a breakpoint is an intentional stopping or pausing place in a program, put in place for debugging purposes. It is also sometimes simply referred to as a pause.
More generally, a breakpoint is a means of acquiring knowle ...
(even in ROM), real-time traces of processor activity, and no use of target resources. But this extra functionality comes at a high cost, as bond-outs have to be produced for
in-circuit emulator
In-circuit emulation (ICE) is the use of a hardware device or in-circuit emulator used to debug the software of an embedded system. It operates by using a processor with the additional ability to support debugging operations, as well as to ca ...
s only.
Therefore, sometimes solutions similar to bond-outs are implemented with an ASIC or FPGA or a faster RISC processor that imitates the core processor code execution and peripherals.
[Debugging Embedded Systems Using In-Circuit Debuggers - Nikkei Business Publications, Inc. December 2002 Issue]
References
{{Reflist
External links
* http://www.embedded.com/design/debug-and-optimization/4395414/Real-Time-Debugging-with-ROM-Monitors
Embedded systems