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Tibbo Project System (TPS)
© Tibbo Technology Inc.
Plus1 (SP7021) CPU
Introduction
Although there are many embedded Linux CPUs on the market, few were designed to
directly address the needs of the IoT and industrial control markets. Most CPUs
found on popular boards such as the Raspberry Pi were initially meant for something
else (for example, a set-top box) and were merely repurposed for the needs of the
IoT and industrial control communities.
Such CPUs usually have adequate processing power but lack I/O features, which is
not surprising: Set-top boxes have very different I/O needs than IoT or industrial
control devices. These CPUs are also rather complex, need multiple additional
components to work, are available only in difficult-to-handle BGA packaging, and
require six or eight-layer boards. All this poses severe obstacles to low and medium-
volume device vendors.
Take the BGA packaging as an example. Everything about BGA is an order of
magnitude more complex compared to other packaging choices, such as LQFP. BGA
represents the cut-off line, where it becomes impossible to handle the chips
manually. Everything from soldering to desoldering and verifying the assembly quality
requires specialized and expensive equipment. Smartphone manufacturers accept
BGA challenges as the inevitable side effect of the desired board miniaturization that
the technology enables, but vendors of IoT or industrial control devices view this
differently. IoT and industrial control products rarely have any size pressure, and
having to deal with ever-smaller IC packages only brings complications without any
apparent benefits.
As another example, consider the logic levels of GPIO lines. As processor designs
take advantage of ever-more advanced fabrication processes, chip supply voltages
have also decreased. Subsequently, standard semiconductor I/O libraries have
dropped support for 5V and even 3.3V logic levels. This did not bother the designers
of set-top boxes and other "closed" products but was bad news for the architects
of control hardware.
To summarize, there was an apparent gap between existing processor offerings and
the requirements of IoT and industrial control applications. Recognizing the unmet
needs of IoT and industrial control vendors, Sunplus Technology Co., Ltd. and Tibbo
Technology, Inc. in late 2017 set out to develop a Linux-grade chip that would
directly address these markets. The idea was to create a powerful SoC with I/O
features and packaging specifically targeting IoT and industrial control applications,