Apparatus to remotely switch and operate JTAG / TTY / reset signals, and application for low level instruction debug in a distributed computing environment.
Publication Date: 2010-Aug-16
The IP.com Prior Art Database
This invention is focused on enabling new debug tools and methods which enable more efficient work in the unique environment of the new eCLipz High End distributed controller. Described is a hardware solution that enables both a low level hardware debug process on a distributed computing environment of a large amount of input channels, as well as the application of low level distributed instruction tracing in the same environment.
Apparatus to remotely switch and operate JTAG / TTY / reset signals, and application for low level instruction debug in a distributed computing environment .
The problem is encountered in the new and unique eCLipz High End distributed controller environment; because it is unique, the environment requires unique solutions simply to work within it.
The many components of the eCLipz environment make the debug process difficult. In the eCLipz High End environment there are:
• Multiple Nodes, each needing two micro controllers or node controllers
• For each micro controller, a corresponding TeleType (TTY) output signal and an IEEE 1149.1 Joint Test Action Group (JTAG) debug port connection, both of which are essential for debug
• Two system controllers per system which have similar signals
• Eight nodes, * two Node controllers, plus two system controllers, plus two Bulk Power Controllers (BPCs), equalling 20 micro controllers on each system, forming a distributed computing environment
Thus, there are 20 IEEE 1149.1 JTAG port connections and 20 TTY connections which have important outputs. The debug of the entire eCLipz High End system might require those outputs.
The problem is, in order to access one JTAG debug port, analysts must use an expensive device called a RISCWatch. In addition, for each serial port analysts need either a serial port expander card (which would also be expensive) or multiple host companion boxes. For analyst, there are two undesirable options to enable effective debug of the eCLipz HE: either manage a lot of manual reconnection of the various hardware debug ports, or provide each and every prototype system with supporting hardware, which would prove very costly.
This invention describes a hardware solution that enables both a low level hardware debug process on a distributed computing environment of a large amount of input channels, as well as the application of low level distributed instruction tracing in the same environment.
By using one multiplexer that is remotely selected via a parallel port connection to switch between the 20 JTAG signals, and another multiplexer, also remotely switched by a different pin from the same parallel port connection, to switch between the 20 TTY signals, analysts can use one companion box, one RISCWatch, and one custom multiplexing device to enable a robust remote controlled development
environment. Any time the user needs to work on a different micro controller, they can send a remote command which automatically targets the debug signals to a different micro-controller.
Known hardware solutions to this problem are limited to buying more debug hardware such as serial port expander devices or additional RISCWatch devices. The main drawback of the known hardware solutions is the additional cost incurred by purchasing the extra debug hardware. There are also no known solutions that incorporate toggling the reset line to the controller as part of the design....