he TZ1200 is the latest ApP LiteTM graphics / application processor from Toshiba Electronics Europe, based upon a high performance 32-bit ARM® Cortex®-M4F RISC floating-point processor capable of operating at speeds of up to 120MHz.
A particularly important aspect of the TZ1200 is the high-precision analogue front-end (AFE) that brings together multiple analog-to-digital and digital-to-analog converters. This allows analog sensors to be connected directly to the high-resolution TZ1200 delivering significant space and power savings. By eliminating the traditional ‘pre-conditioning’ hardware elements, the TZ1200 performs these functions in software running directly on the processor.
Four inbuilt hardware graphics engines (GFX) allow rendering of realistic graphics displays that far exceed the needs of most wearable applications. Yet, due to the efficient and segregated bus architecture, the workload on the main Cortex processor is minimized, thereby retaining capacity for increasing the wearable device's functionality.
While the GFX enables highly sophisticated, feature rich user interfaces, the real strength of the TZ1200 comes from its dual-bus architecture. The GFX is, in effect, an autonomous sub-system with its own memory and display interface. The main processor prepares a command list, based upon the needs of the device, and sends this short set of instructions to the GFX. The GFX interprets these high-level instructions into tasks for each of the graphics engines and then executes them directly to the display interface.
This highly efficient architecture allows the TZ1200 to achieve performance often associated with significantly higher speed processors. This, along with advanced features such as the ability to power down memory banks and on-chip features individually, contributes significantly to the extremely low power consumption of the TZ1200.
Indeed, when tested in an 'always on' watch application with a color display that updates every second, the TZ1200-based solution, allowed the watch to operate with a small (350mAh) battery for 34 days between charges.
In the fast-changing and highly competitive world of wearable technology, the intelligent approach of separating the graphics engine from the general processing delivers real benefits in terms of high performance at a reduced clock frequency. This allows designers to meet the power budget AND deliver the high-functionality, eye-catching, graphical user interfaces that will define the compelling wearable products of the future.