Rainbow Electronics AT89S53 - Manual

1
Features
• Compatible with MCS-51 ™ Products
• 12K Bytes of In-System Reprogrammable Downloadable Flash Memory
– SPI Serial Interface for Program Downloading
– Endurance: 1,000 Write/Erase Cycles
• 4V to 6V Operating Range
• Fully Static Operation: 0 Hz to 24 MHz
• Three-level Program Memory Lock
• 256 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Three 16-bit Timer/Counters
• Nine Interrupt Sources
• Programmable UART Serial Channel
• SPI Serial Interface
• Low-power Idle and Power-down Modes
• Interrupt Recovery From Power-down
• Programmable Watchdog Timer
• Dual Data Pointer
• Power-off Flag
Description
The AT89S53 is a low-power, high-performance CMOS 8-bit microcomputer with 12K
bytes of downloadable Flash programmable and erasable read only memory. The
device is manufactured using Atmel’s high-density nonvolatile memory technology
and is compatible with the industry-standard 80C51 instruction set and pinout. The on-
chip downloadable Flash allows the program memory to be reprogrammed in-system
through an SPI serial interface or by a conventional nonvolatile memory programmer.
By combining a versatile 8-bit CPU with downloadable Flash on a monolithic chip, the
Atmel AT89S53 is a powerful microcomputer which provides a highly-flexible and
cost-effective solution to many embedded control applications.
The AT89S53 provides the following standard features: 12K bytes of downloadable
Flash, 256 bytes of RAM, 32 I/O lines, programmable watchdog timer, two Data Point-
ers, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full
duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S53 is
designed with static logic for operation down to zero frequency and supports two soft-
ware selectable power saving modes. The Idle Mode stops the CPU while allowing the
RAM, timer/counters, serial port, and interrupt system to continue functioning. The
Power-down mode saves the RAM contents but freezes the oscillator, disabling all
other chip functions until the next interrupt or hardware reset.
The downloadable Flash can change a single byte at a time and is accessible through
the SPI serial interface. Holding RESET active forces the SPI bus into a serial pro-
gramming interface and allows the program memory to be written to or read from
unless Lock Bit 2 has been activated.
Rev. 0787D–06/00
8-bit
Microcontroller
with 12K Bytes
Flash
AT89S53