Microcontroller
by Damián
- Pin Usage
- Microcontroller, DSPs & DSCs
- Advantages and Disadvantages of DSCs
- Comparison Table updated
Pin Usage
Before the team decided to use the Arduino Diecimila board. This was a previous idea of what the pin usage was going to be for the selected microcontroller.pin_usage.odg - Need of openoffice.org to open this archive.
Microcontroller Research
From the article: The evolution of the digital signal controller
All of the operations that can be performed on a DSP can be performed on an MCU
Digital Signal Controller (DSC = DSP + MCU), include all of the features listed below
Microcontrollers: MCU
- Optimized to perform a wide array of logical, diagnostic, and arithmetic operations on almost any combination of input data from various sources.
- General-purpose capability.
- Control-orientated instructions, bit-manipulation instructions.
- Ability to manipulate data easily using the stack pointer.
- Inclusion of on-chip peripherals.
- Fast interrupt-handling capability.
Digital signal processors: DSP
- Very efficient at repetitive, numerically intensive tasks.
- Specific hardware to perform the multiply and accumulate (MAC) operation as well as guard bits in the accumulator.
- Ability to access multiple memory locations simultaneously.
- Address generation while instructions are being processed.
- Circuits used to manipulate register contents quickly in order to scale data.
From the article: Control and signal processing: Can one processor do it all?
Unified architectures
- (A) Make it easier for designers to ease into signal processing with formerly control-only applications.
- (A) Immediate access to control and DSP functions under a single memory map and a single set of tools.
- (A) Reduce asynchronous threads.
- (A) Data and time dependencies are easier to see.
- (A) Simplify system integration.
- (D) Require higher clock rates, Therefore
- (D) Higher power consumption.
Dual-heterogeneous core systems
- (D) Are more complex than unified architectures.
- (D) Designers must obtain and learn two languages or variants as well as the idiosyncrasies of two tool sets.
- (D) No immediate access exists between the microcontroller and DSP.
- (D) Developers must build the interprocessor-communication mechanisms and protocols.
- (A) Enjoys a degree of autonomy between the instruction threads. Software changes on one processor may have little or no effect on the other processor. Changing the user-interface code in a dual-configuration system rarely impacts the signal-processing thread.
- (A) Independently clock each core at the rate the application requires.
Table comparing some of the architectures
| Key parameter | AT91SAM7S256 | Atmega168 | dsPIC30F6011A | AT91SAM7A3 | PIC24HJ |
|---|---|---|---|---|---|
| Manufacturer | ATMEL | ATMEL | Microchip | ATMEL | Microchip |
| Architecture (bits) | 32 MCU | 8 MCU | 16 DSP | 32 MCU | 16 MCU |
| Flash (Bytes) | 256K | 16K | 144K | 256K | up to 256K |
| EEPROM (Bytes) | - | 0.5K | 4K | - | - |
| SRAM (Bytes) | 64K | 1K | 8K | 32K | up to 16K |
| RTC/RTT | -/1 | yes/- | RTC for timer | -/1 | RTC for timer |
| ADC Channels | 8 (10bits) | 6/8(10bits) | 16(12bits) | 16(10bits) | up to 32 (10 or 12bits) |
| Peripheral DMA Channels | 11 | - | - | 19 | 8 |
| Max. RC Clock Speed (Mhz) | 3 - 20 | 8 | 7.37 | 22Khz - 42Khz | 7.37 |
| Max. Instruction Speed (Mhz) | 55 | 20 | Up to 60 | 60 | up to 80 |
| I/O Pins | 32 | 23 | 68 | 62 | 85 |
| Enhanced USART | 2 | - | - | - | - |
| USART/DBGU | -/1 | 1/- | 1/- | 3/1 | -/- |
| UART | - | - | 2 | 1 | 2 modules |
| SPI | 1 | 1 | 2 | 2 | 2 |
| TWI | 1 | yes | - | 1 | - |
| SSC | 1 | - | - | 2 | - |
| USB Device | FS | - | - | FS | - |
| PWM Controller | 4 | 6 | yes | 8 | up to 8 |
| High Current Pads | 4 | - | - | - | - |
| 32-bit Timers | - | - | 2 | - | up to 4 |
| 16-bit Timers | 3 | 1 | 5 | 9 | up to 9 |
| 8-bit Timers | - | 2 | - | - | - |
| Period Interval Timer | 1 | - | - | 1 | - |
| Watchdog Timer | 1 | yes | yes | 1 | yes |
| Power-On-Reset | 1 | yes | yes | 1 | yes |
| Brown Out Detection | 1 | yes | yes | - | yes |
| On-chip RC Oscillator | 1 | On chip oscillator | with WDT | 1 | yes |
| Crystal Oscillator/PLL | 1/1 | On chip oscillator | ?/yes | 1/1 | both |
| Interrupts Internal/Ext Sources | ? | 26/26 | 36?/5 | 27?/5? | 61/5 |
| I/O Voltage Domain (V) | 3.3 | 1.8 - 5.5 | 2.5 – 5.5 | 3.3 | 3.0-3.6 Digital inputs 5V |
| PB Free Packages | QFN 64 LQFP 64 | TQFP 32, MLF 32, PDIP 28 | TQFP 80 | LQFP 100 | TQFP 64 or 100 |
RTC Real Time Clock, RTT Real Time Timer, WDT Watch Dog Timer, USART Universal Synchronous/Asynchronous Receiver Transmitter, SPI Serial Parallel Interface, SSC Synchornous Serial Controller, TWI Two Wires Interface
page_revision: 16, last_edited: 1209655085|%e %b %Y, %H:%M %Z (%O ago)
