Microcontroller Peripherals

Most applications which are built around an embedded microcontroller or DSP core require peripheral devices to perform system management tasks. Atmel can provide a wide range of these peripherals as on-chip macrocells. All follow established industry-standards, including a series which is compatible with the ARM7 Peripheral Bus (APB), and one for the AVR microcontroller core.

Industry-standard microcontroller peripherals include:

Programmable USART
Atmel offers the choice between an 8251-compatible and a 16450-compatible device. Both offer synchronous and asynchronous operation, full duplex, with support for all standard serial data formats.

Real Time Clock
This 146818-compatible device features a 100-year calendar, programmable periodic interrupts and a RAM interface. Power consumption is exceptionally low so that the device can be left running when the system is in stand-by mode.

Programmable Interrupt Controller
This 8259-compatible low-power device features 8 interrupt priority levels. It is cascadable up to a maximun of 64 levels.

Programmable Peripheral Interface
Following the 8255 standard, this device features three 8-bit ports which can be programmed as inputs or outputs, by a standard microprocessor interface.

Extended Programmable Interval Timer
This 8254-compatible device features three independent 16-bit counters, with optional single-byte and BCD modes.

Serial Communication Controller
Following the 82530 standard, this device has both synchronous and asynchronous modes, supporting monosync, bysinc and SDLC protocols.

DMA Controller
This 8237-compatible device provides four independent direct memory access (DMA) channels, cascadable for additional channels as required.

ARM7-Compatible Peripherals
ARM7-compatible peripherals include a memory controller, interrupt controller, counter-timer, DMA controller, USART, watchdog timer, clock generator and advanced power management controller.