AT89LP51 datasheet(6/113 Pages) ATMEL

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3709B–MICRO–12/10

AT89LP51/52 - Preliminary

Overview

The AT89LP51/52 is a low-power, high-performance CMOS 8-bit microcontroller with 4K/8K

bytes of In-System Programmable Flash program memory and 256 bytes of Flash data memory.

The device is manufactured using Atmel's high-density nonvolatile memory technology and is

compatible with the industry-standard 80C52 instruction set.

The AT89LP51/52 is built around an enhanced CPU core that can fetch a single byte from mem-

ory every clock cycle. In the classic 8051 architecture, each fetch requires 6 clock cycles, forcing

instructions to execute in 12, 24 or 48 clock cycles. In the AT89LP51/52 CPU, instructions need

only 1 to 4 clock cycles providing 6 to 12 times more throughput than the standard 8051. Sev-

enty percent of instructions need only as many clock cycles as they have bytes to execute, and

most of the remaining instructions require only one additional clock. The enhanced CPU core is

capable of 20 MIPS throughput whereas the classic 8051 CPU can deliver only 4 MIPS at the

same current consumption. Conversely, at the same throughput as the classic 8051, the new

CPU core runs at a much lower speed and thereby greatly reducing power consumption and

EMI. The AT89LP51/52 also includes a compatibility mode that will enable classic 12 clock per

machine cycle operation for true timing compatibility with AT89S51/52.

The AT89LP51/52 provides the following standard features: 4K/8K bytes of In-System

Programmable Flash program memory, 256 bytes of Flash data memory, 256 bytes of RAM, up

to 36 I/O lines, three 16-bit timer/counters, a programmable watchdog timer, a full-duplex serial

port, an on-chip crystal oscillator, an internal 1.8432 MHz auxiliary oscillator, and a four-level,

six-vector interrupt system. A block diagram is shown in Figure 2-1.

All three timer/counters of the AT89LP51/52, Timer 0, Timer 1 and Timer 2, can be configured to

toggle a port pin on overflow for clock/waveform generation. Unlike AT89S51, Timer 2 is also

present on AT89LP51.

The enhanced full-duplex UART of the AT89LP51/52 includes Framing Error Detection and

Automatic Address Recognition. In addition, enhancements to Mode 0 allow hardware acceler-

ated emulation of a Serial Peripheral Interface (SPI) or a Two-Wire Interface (TWI).

The Watchdog Timer of the AT89LP51/52 includes a 7-bit prescaler, a software reset command

and an overflow flag. The watchdog can be configured to output a reset pulse on the external

Reset pin.

Each 8-bit I/O port of the AT89LP51/52 can be independently configured in one of four operating

modes. In quasi-bidirectional mode, the port operates as in the classic 8051. In input-only mode,

the port is tristated. Push-pull output mode provides full CMOS drivers and open-drain mode

provides just a pull-down. Unlike other 8051s, this allows Port 0 to operate with on-chip pull-ups

if desired.

AT89LP51 датащи(PDF) 6 Page - ATMEL Corporation