1. February 26, 2015 Jacob Beningo, CSDP
Baremetal C Programming for Embedded Systems
Class 4: Design Patterns for Firmware
February 26, 2015 Jacob Beningo, CSDP

2. Course Overview C Concepts for Embedded Systems
Baremetal Scheduling Techniques
Driver Design Techniques
Design Patterns for Firmware
Writing Portable Code

3. Session Overview Defining Design Patterns Circular Buffers
A SPI Driver Example

4. Defining a Design Pattern
Pattern – a model or design used to guide development
Common Repetitive
Operating System
Drivers
Buffers
Design elements (pushbuttons, leds, etc)
Opportunities to reuse
Save cost and development time

5. Circular Buffers Definition
A circular buffer is a data structure that uses a single, fixed-size buffer as if it were connected end-to-end. (Wikipedia hehe)

6. Circular Buffer Design

7. Circular Buffer Implementation

8. Driver Design Process Developing drivers will follow a simple process
Develop the structure for the configuration table
Create the peripheral channel list
Populate the configuration table
Define the pointer arrays
Define initialization functions
Define application functions

9. Serial Peripheral Interface (SPI)

10. Blocking vs. Non-Blocking
MCU
Device
MCU
Device

11. Serial Peripheral Interface (SPI)
Configuration Table Definition
Mode
Baud Rate
Communication
etc

12. Serial Peripheral Interface (SPI)
Transfer Configuration Table Definition
Phase and Polarity
Buffer
etc

13. Serial Peripheral Interface (SPI)
Channel Definition
Each channel can be given an identifier
Used to identify the element in the configuration table

14. Serial Peripheral Interface (SPI)
Configuration Table Setup

15. Serial Peripheral Interface (SPI)
Pointer Arrays
Functions

16. Serial Peripheral Interface (SPI)
Spi_Transfer

17. Serial Peripheral Interface (SPI)
Spi_Transfer

18. Serial Peripheral Interface (SPI)
Spi_SetCs

19. Additional Resources Download Course Material for
Updated C Doxygen Templates (Feb 2015)
Example drivers source code
Microcontroller API Standard
EDN Embedded Basics Articles
Embedded Bytes Newsletter
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