1. Programming Microcontroller
uC System
2- 1
Programming Microcontroller
uC System
Week 1 – Spring Term 2017
32K Byte Burst Flash
64K or 96K Byte SRAM
256K or 512K Byte Burst Flash
OTP Mem
UART
I2C
SPI
TIM
RTC
EXT. Bus
GPIO
USB 2.0FS
CAN 2.0B
Enet MAC
PFQ BC
DMA
INTR Cntl
ARM966E
CORE
w/DSP
96 MHz
CLK Cntl
ADC
LVD BOD
PLL
JTAG
ETM9

2. Architecture of uC Systems
2- 2
Only one address space
Program instruction
Program memory (ROM)
Program data
Data memory (RAM)
Instruction and data are accessed sequentially
Information exchange runs over the same bus
Program
memory
Data
Periphery
CPU

3. Central Processing Unit
uC System
Central Processing Unit
2- 3
Core of the computer
Interpret the program instructions and process of the data

4. Control unit is responsible for the execution of the program
uC System
2- 4
Control unit is responsible for the execution of the program
Instruction unit
Interpret and execute the program instructions
Program counter
Contains the address of the next instruction
Task of the control unit
Load the program instructions (fetch)
Decode the program instructions (decode)
Execute the program instructions (execute)
Generate the control signals for the other units
Address and load the operands
Store the result
Adapt the program counter

5. Processing unit contains the following components
uC System
Processing unit
Processing unit contains the following components
ALU (Arithmetic Logical Unit)
Execute arithmetic and logical operations
FPU (Floating Point Unit)
Execute floating point operations
Register
Store the operands and the result
Bus interface
Activation of the external units
Internal bus connects the control unit, processing unit and the bus interface

6. uC System
Bus system
2- 6

7. The components of the bus system
uC System
The components of the bus system
Address Bus
Transfer of address information
Use of additional address decoders
Data Bus
Transfer of program instructions and user data
CPU reads from the external units
CPU writes in the external units
Control Bus
Additional control informations
Read, Write, Reset, Interrupts, Requests, Acknowledge …

8. Read the temperature from the sensor “x”
uC System
Example
2- 8
Read the temperature from the sensor “x”
Store its value into the variable “temp”
int temp = Temperature_Sensor_x;

9. Data Transfer CPU sets the address of the program instruction
uC System
Data Transfer
2- 9
CPU sets the address of the program instruction
CPU defines the transfer direction read
Program memory outputs the instruction on the data bus
CPU reads the instruction to be executed
CPU sets the address of the temperature register
Peripherals outputs the information to the data bus
CPU reads the value of the temperature
CPU sets the address of the variable temp
CPU defines the transfer direction write
CPU places the data on the data bus
Data memory takes the data from the data bus

10. Plan of the memory allocations in a microcontroller system
uC System
Memory-Map
2- 10
Plan of the memory allocations in a microcontroller system
Address fields of the memory components
Address fields of the peripheral components
Example
Adresse
A15
A14
A13
A12
Periphery
0xFFFF 1
0xE000
Not used
RAM
(8kByte) 
0xBFFF
0xA000
0x9FFF
0x8000
ROM
(32kByte)
0x7FFF

11. Non-volatile Memory types
uC System
Memory
2- 11
Non-volatile memory
The contents remain after switching off
Non-volatile Memory types
ROM (Read Only Memory)
Masks programmed
EPROM (Erasable Programmable ROM)
Special programming devices
Can be erased with UV light
EEPROM (Electrical Erasable Programmable ROM)
Electrically erasable and reprogrammable (line by line)
Small storage capacity (~ kByte)
FLASH
Electrically erasable (block by block)
Very large storage capacity (~ MByte)

12. Memory Volatile memory Volatile Memory types
uC System
Memory
2- 12
Volatile memory
The memory contents are lost after switching off
Volatile Memory types
RAM (Random Access Memory)
DRAM (Dynamic RAM)
Keep the information in a capacity
Must be periodically refreshed
SRAM (Static RAM)
Complex construction
Do not need a refresh cycle
SDRAM (Synchronous Dynamic RAM)
Clocked variant of the DRAM
Clock is specified by the system bus

13. Each storage technology has its advantages and disadvantages
uC System
Memory hierarchy
2- 13
Each storage technology has its advantages and disadvantages
Memory is therefore organized hierarchically

14. Fast intermediate memory for frequently required data
Cache
uC System
2- 14
Fast intermediate memory for frequently required data
Between register and memory
CPU reads code or data from memory
These objects are automatically stored in the cache
These objects are read by the cache next
Data does not exist in the cache => Cache Miss
Data is read from memory and stored in the cache
Data is in the cache => Cache Hit
Data is read from the cache
Cache are typically 100K bytes

15. Memory for program code (Flash) and data (RAM) PC world
uC System
Working memory
2- 15
Memory for program code (Flash) and data (RAM)
PC world
Code is copied from the mass storage into the working memory and executed from there
Embedded world
Code is executed from Flash
Code is copied from flash into the working memory and run from there

16. Mass storage devices are hard disks, CD, memory sticks etc.
uC System
Mass storage
2- 16
Mass storage devices are hard disks, CD, memory sticks etc.
Embedded system do not contain mass storage
Mass storage, however, are found in industrial PCs
Following storage media are used because of the mechanical environment
CF cards
SD cards
Memory Sticks

17. uC System
Periphery components
2- 17
The following components are referred to as peripherals
Reading external data (sensors)
Data output (actuators)
Interface between processor and environment
Connection to the processor bus

18. Input and output of digital signals
uC System
Digital Input / Output
2- 18
Input and output of digital signals
Microcontroller Pins (GPIO)
Access via register
Use of additional peripherals (FPGA, PIO, ...)
Access via bus system
Use of digital output
Indicators (lamps, LEDs, ...)
Relay
Motor
Valves
Use of digital input
switch
Buttons
Optocoupler

19. Digital outputs are used with amplifier stages
Using GPIO
uC System
2- 19
Digital outputs are used with amplifier stages
Control of motors
Valves
Digital inputs are filtered and protected against overvoltage
RC links & Schmitt triggers
Transzorb diodes, varistors and gaseous conductors

20. Data transmission is realized with a serial bit stream
uC System
Serial interface
2- 20
Data transmission is realized with a serial bit stream
RS232, I2C, SPI, FireWire, USB, Fieldbus, ...
Convert data format from parallel to serial with shift register
Main characteristics
Baud rate, voltage level & protocol

21. Very common in the embedded area
uC System
RS232
2- 21
Very common in the embedded area
Use with LCD display, CLI (Command Line Interface), ...
Many microcontrollers already have an RS232
Output level is however TTL
RS232 are addressed via registers
Send & receive buffer
Often both buffers are at the same address
Control register for defining the operating mode
Baud rate, data, parity, interrupt, ...
RS232 Support different modes
Asynchronous or synchronous
Timer often generates the baud rate

22. SPI is a serial high-speed bus system
uC System
SPI
2- 22
SPI is a serial high-speed bus system
Use with display, A/D and D/A converters
SPI is always operated in the master slave
Master is responsible for the clock
SPI works full duplex
MOSI and MISO

23. SPI with a Master and 2 Slaves
uC System
SPI with a Master and 2 Slaves
2- 23

24. Time basis for the processor or for external components
Timer
uC System
2- 24
Time basis for the processor or for external components
PWM, baud rate for serial interfaces
Use of 8 or 16 Bit Timer/Counter
Timer operation
Timer register is incremented by oscillator
Counter operation
Timer register is incremented by external signal
Overflows of register set a flag signal

25. Generation of a clock with a defined period duration
Timer
uC System
2- 25
Generation of a clock with a defined period duration
Timer with auto reload

26. Analog voltage  Digital value Most important characteristics
A/D Converter
uC System
2- 26
Analog voltage  Digital value
Reading in the result with bus system or serial interface
Most important characteristics
Size of the result (8, 10, 12 or 16 bits) and conversion time

27. Digital value  Analog voltage Most important characteristics
D/A Converter
uC System
2- 27
Digital value  Analog voltage
Most important characteristics
Bit width of the digital value (8, 10, 12 or 16 bits)
Conversion time