The S8051XC3 IP core implements a high-performance, low-energy, 8-bit microcontroller that executes the MCS®51 instruction set and includes a configurable range of features and integrated peripherals.
The core’s sophisticated architecture yields the fastest 8051-compatible 8-bit MCU available anywhere (at the time of its release). It runs with a single clock per machine cycle, and requires an average of 1.5 to 1.8 machine cycles per instruction, depending on configuration. Dhrystone 2.1 tests show it to run from 9.41 to 26.85 times faster than the original 8051 at the same frequency, without requiring an external arithmetic acceleration unit (such as an MDU). Representative 40nm ASIC results have reached 635 MHz for the most advanced version, for an effective speed up of 1,400 times over 80C51 chips. Interrupt latency is a remarkably low two cycles.
The S8051XC3 is also one of the most energy efficient 8-bit processors available. Its small silicon footprint—the CPU size can be 6,000 gates—means very little power leakage. Furthermore, dynamic power of the CPU at a 40nm technology is as low as 2.7μW/MHz, and its higher performance allows clocking at lower frequencies. The core allows energy consumption to be adjusted to the processing workload via dynamic frequency scaling and independent control of the CPU and peripherals clock.
The core’s rich set of optional features and integrated peripherals allows designers to adjust performance and silicon requirements to best match an application’s specific requirements. (Several pre-configured versions at different price points are also available.) Software development is facilitated by a single-wire or JTAG debugging interface, which operates seamlessly within IDEs such as those from IAR and Keil.
This core builds on CAST’s experience with hundreds of 8051 IP customers going back to 1997. Designed for easy reuse in ASICs or FPGAs, the core is strictly synchronous, with positive-edge clocking (except in the optional debug & SPI modules), synchronous or asynchronous reset, and no internal tri-states.
