Post on 27-Mar-2015
What are Embedded Systems• They are Embedded ‘in’
• They are not desktops
• Not mainframes or mini’s
• Automotive- engine, doors, mirrors• A heating furnace controller- Thermostat
• A mobile phone
• Medical device
• DSP based systems
• Avionics
Why Use Embedded Systems• User functionality – portability
• User convenience, comfort - HVAC, Auto,
Appliances, GPS, TV remote, DVR, iPod • Low power and safety – iron, coffee maker, LED Lighting
• Commercial/industrial applications• Complex features to be simplified• Replace electro-mechanical systems• Cost reduction• Quality improvement
Microcontroller Manufacturers• ARM – Advanced RISC Machines• Atmel• Cypress- programmable blocks• Freescale Semiconductor- uC, DSP
• Intel- 8051/8052 cores• Microchip• NEC• Renasas• Sharp• ST Microelectronics• Texas Instruments- uC, DSP• Many others
Microcontrollers Spectrum• $0.15 - $0.20 Far Eastern parts
• A 4-bit 4-pin $0.35 ST part
• Musical gift card uC
• 8-bit 8K flash,1K RAM, 16-I/O
• 8-Bit, 256K flash, 32K RAM, 64-I/O
• 32-Bit, 2M Flash, 64K RAM, TPU• A high end $50 Marvell processor – GbE, USB HS
• DSPs
A Low End Microcontroller
MicrochipPIC10F200
I/O(3)
RAM16 Bytes
Flash256 x 12
Clock
WatchDog
Input (1)
Reset
PIC10F200 Microcontroller• 33 12-bit wide instructions• 2-level deep stack• 4MHz precision internal clock• Sleep mode – 100nA• Internal pull-ups• 3 Input/Output – direct LED drive
• 8-bit Timer – programmable prescaler
• Options – Comparator, memory
• $0.34/3K, $0.59/1
Microcontroller Functionality• Core processor - Voltages
• Memory – Flash, RAM, EEPROM, FRAM, DDR2
• Input/Output – interface voltage
• Timers
• Interrupts• Serial Communication- SPI, I2C, UART
• USB, CAN-BUS, IR, SD-Cards • Analog – A/D, DAC, Comparator, Op-amp
Power-On Reset Modules• Internal reset
• Internal and/or external reset
• Programmable threshold voltage
• Programmable duration
• Programmable Osc startup time
• Brown-out condition - programmable
• Hysteresis
• Watchdog timer
Battery Powered Applications• Sleep mode
• Currents down to 20nA
• All kinds of modes available
• Reduced clock frequencies
• Core options
• Selective peripherals sleep mode
• Wake up modes – clocks, timers, interrupts
• Watchdog timer
A High End Microcontroller
Freescale32-Bit
MPC5554
64-Ch I/O
32-Bit External Bus
2MB Flash
A/D40-Ch
CAN Bus(3)
MMU
32-Ch
TP
U(2)
32K C
ache
DS
P
64-Ch
DM
A
PLL
64KB SRAM
JTAG NEXUS
Freescale MPC5554 uC• 132MHz, 416-Pin Plastic BGA
• ECC Flash, SRAM• Interrupt controller – 286 prioritized leves
• PLL – frequency modulated for EMI
Applications
• Engine control
• Avionics
• Turbine control
Microcontroller Selection Criterion• Speed of operation, complexity – 8/16/32 Bits
• Cost – HW/SW tradeoffs• Power consumption - TI, Microchip, Freescale
• Memory Size – Flash, RAM, EEPROM
• # of I/O• Analog – A/D, DAC, Comparator, Op-amp
• Serial Communication- SPI, I2C, USB, IR, GbE
• Product Family
• Development tools
• Timers – input capture, output compare
• Environmental conditions
Marvell 88F6281
Sheeva Core1.2 GHz
PCI-E
DDR2Ctlr
FlashCtlr
MPEGAudio
2xTDM
2xSATA2xGbEMAC
USB 2.0HS
Embedded Systems Development
• System development
• Electronics
• PCB Layout
• Software
• Mechanical
• Product qualification• DFM – design for manufacturability
System Development
• Architecture• Complexity- MIPS required
• Sub-systems interface - Master/slave
• Communication - Networking protocols
• Power budget• HW/SW tradeoffs• uC selection• System tests – regulatory agencies
Electronics Development
• Design specs
• Design for testability• uC and components selection• Worst case analyses• Schematics – CAD tools, Design rule checks
• Simulations• Proof of concept, Prototyping• Design validation• Product qualification
Electronics Development Tools
• Schematic capture- Orcad, PADS, Cadence, Mentor
• Analog simulation- pSpice, LTSpice
• Logic Simulation- Orcad, Cadence, Mentor
• VHDL, Verilog
• Worst case analyses- simulations
• Proof of concept, Prototyping- PALs, FPGAs
• DFMEA- UL, agencies approval
• Reliability predictions - MTBF
ASICs & Programmable Logic
• Application Specific ICs• PAL, PLD, FPGA- uCs with PLDs
• Gate Arrays• Standard Cells• Custom ICs• Languages- VHDL, Verilog
• Functional simulation• Timing simulations• Floor planning• Back-annotation
PCB Layout
• CAD tools- Orcad, Protel, PADS, Allegro, Mentor
• Netlist• # of layers• Mechanical outline• 3D fit• Noise considerations- diff-pair, impedance-matching
• Thermal considerations• DRC• Gerber output• Fabrication
Software Development
• Specs• Architecture• SW Design• Languages – ‘C’, C++, Assembly
• OS’• Simulations• Tools – compilers, assemblers, programmers, emulators
• Real time aspects - ISRs• SW/HW tradeoffs• System integration
Real Time Software
Micro-ControllerCore SW
Timer 1
PrioritizedInterrupts
Task 1
Timer n
Task 2
Task n
ExternalEvent
ExternalEvent
InputsI/O
Real Time Software Development
• Interrupts – ISRs
• ‘C’ v/s Assembly• Timers – input capture and output compare
• Tasks and priorities
• RTOS’
• Worst case analysis
Software Development - Tools
• Programmers- development, in-circuit, field
• Emulators- JTAG
• Simulators• Assemblers• Compilers• Linkers• Loaders• CASE tools• Version control
Mobile Phone User Interface
FreescaleDragonball
68328
LCD Driver
KeypadInputs
Freescale68HC05
Micro-Phone
Speaker
TouchScreen
GraphicsLCD
PowerBattery
Radio
Mobile Phone Development
• 3.5 Months total development time
• Development involved– HW– SW- menus, address book– GUI – electronic ink capture– Plastics industrial design, proto tooling– Fonts– Phone made and received calls
• Project successfully completed
Postal Mail Sorting Device
Freescale68HCxx
PostalMail
Pieces
OpticalEncoder
PowerSupply
RS232
FlashRAMPLD
PCApplication
OpticalIsolation
Mail Sorter Development
• 6 Months total development time
• Industrial robustness
• Development involved– HW
– SW- timers
• Project successfully completed
• Product went to production
eBook
• 6 Months total development time
• Proof of concept
• Development involved– HW– FPGA for orthogonal rotation of image– SW- PC Application– Industrial design- leather bound covers
• Project successfully completed
• Idea was discarded by the customer
1GHz Fibre Channel PCI Card
• 3 Months total HW development time
• SAN Storage Area Networking
• 1GHz Fibre Channel Bus
• LSI Logic FC controller
• Technician did the Orcad PCB Layout
• Windows Driver development