ATXMEGA32E5-AU

The ATXMEGA32E5-AU from Microchip (formerly Atmel) is a member of the AVR XMEGA E5 family, offering advanced 8/16-bit AVR architecture with innovative peripherals in a compact 44-pin TQFP package. The XMEGA architecture extends the classic AVR instruction set with 16-bit operations, DMA controller, and the revolutionary Event System. The Event System is a network of 8 independent channels that allows peripherals to signal each other directly without CPU intervention, enabling real-time response to events (ADC complete, timer overflow, pin change, comparator trip) with zero latency and zero CPU overhead. This is particularly powerful for creating autonomous peripheral interactions such as ‘timer overflow triggers ADC conversion, ADC complete triggers DMA transfer’ all without a single CPU instruction. The 12-bit 200ksps ADC supports signed differential measurements, enabling direct measurement of bridge sensors (strain gauges, pressure sensors) without external instrumentation amplifiers. The 12-bit DAC provides precision analog output for calibration, bias voltage generation, or waveform synthesis. The 4-channel DMA controller offloads data transfer from the CPU, enabling high-speed continuous data acquisition into SRAM buffers while the CPU processes other tasks. The XMEGA E5 is the smallest member of the XMEGA family, optimized for applications that need the advanced peripheral features (Event System, DMA, 12-bit ADC) in a smaller memory footprint and package than the larger XMEGA devices.

The ATXMEGA32E5-AU operates as an advanced AVR XMEGA microcontroller. Key subsystems include: (1) AVR XMEGA Core – an enhanced 8/16-bit AVR RISC core with 136 instructions, most executing in a single clock cycle at 32MHz; the core extends the classic AVR with 16-bit register access, hardware multiply (2-cycle), and DMA bus master capability; the 3-level interrupt controller with programmable priority enables deterministic real-time response; (2) Event System – an 8-channel routing network that connects event generators (timers, ADC, comparators, DMA, ports, software) to event users (ADC triggers, timer actions, DMA requests, port actions, DAC updates); events propagate in 1-2 clock cycles without CPU involvement; this enables peripheral chains like Timer0-overflow -> ADC-start-conversion -> ADC-complete -> DMA-transfer; (3) DMA Controller – 4 independent channels with programmable source, destination, and transfer count; burst mode transfers up to 64KB per transaction; the DMA can access all SRAM and peripheral registers; each channel has configurable priority and can trigger interrupts on block transfer complete; (4) 12-bit ADC – a successive-approximation ADC with 200ksps maximum rate; supports signed differential measurements (positive and negative inputs) with programmable gain (1x, 2x, 4x, 8x, 16x, 32x, 64x); the signed mode allows measuring bipolar signals from bridge sensors; the internal 1V reference enables ratiometric measurements; (5) Crypto Engine – a hardware AES-128/256 and DES engine that encrypts/decrypts data in 375 clock cycles (AES-128), offloading the CPU from cryptographic operations.

• Strain gauge: 12-bit signed ADC measures Wheatstone bridge differential output, Event System chains timer-triggered measurement, DMA buffers 1000 samples
• Low-power sensor: 1.6V minimum supply from coin cell, Event System triggers ADC on comparator trip, CPU sleeps between measurements
• Portable instrument: 12-bit ADC reads sensor, 12-bit DAC generates calibration stimulus, crypto engine secures data, 4KB SRAM for signal buffer
• Industrial I/O: Event System creates autonomous ADC-to-DAC passthrough for analog signal conditioning with zero CPU latency