VRS51L3174 pdf datasheet (High

The VRS51L3174 is a high performance, 8051-based microcontroller
coupled with a fully integrated array of peripherals for addressing a
broad range of embedded design applications.
Based on a powerful 40-MIPS, single-cycle, 8051 microprocessor,
the VRS51L3174’s memory sub-system features 64KB of Flash
and 4352 bytes of SRAM and 8192 Bytes of nonvolatile FRAM
(ferroelectric random access memory) memory.
Support peripherals include a hardware based arithmetic unit capable
of performing complex mathematical operations, a JTAG interface for
Flash programming and non-intrusive in-circuit debugging/emulation,
an internal oscillator, and a watchdog timer.
Communication and control of external devices is facilitated via an
assortment of digital peripherals such as an enhanced, fully
configurable SPI bus, an I²C interface, dual UARTs with dedicated
baud rate generators, three 16-bit timers, 8 PWM controllers each
with a 16-bit timer, and 2 pulse width counter modules.
The VRS51L3174 operates from 3.0 to 3.6 volts over the industrial
temperature range and is available in a QFP-44 package. The device
features an active-low reset and is pin-compatible with an industry
standard 8051 microcontroller footprint.