The VRS51x540 is a low-cost 8-bit microcontroller based on the standard 80C51 microcontroller family architecture. It is pin compatible and can be used as a drop-in replacement for standard 8051 MCUs. The product is aimed at cost-effective applications requiring small amounts of program/data memory coupled with streamlined peripheral support. The VRS51x540 includes 4KB of Flash memory, 128 bytes of RAM, a UART, three 16-bit timers, a Watchdog timer, and power down features. The VRS51x540 is available in 5V (VRS51C540) and 3.3V (VRS51L540) versions in PLCC-44, QFP-44, and DIP-40 packages. The devices operate over the entire industrial temperature range. The Flash memory can be programmed using programmers available from Ramtron or other third-party commercial programmers.
The VRS51x540 is a low‑cost 8‑bit microcontroller based on the standard 80C51 architecture, pin‑compatible with 8051 devices and offered in 5 V and 3.3 V versions.
The datasheet details the device’s 4 KB Flash, 128 B RAM, UART, three 16‑bit timers, watchdog timer, power‑saving modes, pin‑outs for PLCC‑44, QFP‑44 and DIP‑40 packages, full instruction set, special function registers and I/O characteristics.
| Flash memory | 4 KB |
|---|---|
| RAM | 128 bytes |
| UART | Full duplex serial port |
| Timers | Three 16‑bit timers |
| Watchdog timer | Included |
| Operating frequency | Up to 40 MHz |
| Temperature range | -40 °C to +85 °C |
| Supply voltage versions | 5 V and 3.3 V |
| Programming voltage | 12 V |
| I/O lines | 32 bi‑directional I/O lines |
The VRS51x540 contains 4 KB of on‑chip Flash memory.
It provides 32 bi‑directional I/O lines organized as four 8‑bit ports.
The device supports Idle and Power‑Down modes to reduce power consumption.
Programming the Flash requires a 12 V supply.