PowerPoint PresentationSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 241Instructor: Paul GordyOffice: H-115Phone: 822-7175Email: [email protected] 270Fundamentals of Computer EngineeringPresentation for Lab #8Introduction to the MicroStamp11 and 68HC11 Assembly Language ProgrammingLab #8 EGR 270 – Fundamentals of Computer Engineering2Lab #8 EGR 270 – Fundamentals of Computer EngineeringMicroStamp11The MicroStamp11 is a microcontroller or microprocessor. It is built by Technological Arts and is based on the Motorola 68HC11 microcontroller.Technological Arts states that the MicroStamp11 is the world’s smallest microcontroller module.The MicroStamp11 is about the size of a postage stamp!3Lab #8 EGR 270 – Fundamentals of Computer EngineeringMicroStamp11 Breadboard SetupThe MicroStamp 11 is easily used on a breadboard with two modules:•MicroStamp11 Module – fitted with a 20-pin connector that plugs into a breadboard•USB-to-MCU Interface Module – allows for serial communication using a USB port on a computer. The USB connection can also be used to provide power (5V) to the breadboard. A few wires are required as shown below.MicroStamp11 ModuleUSB-to-MCU Interface Module4MicroStamp11 Features (reference: www.technologicalArts.com)Lab #8 EGR 270 – Fundamentals of Computer Engineering5MemoryThere are two types of memory:•ROM (Read-Only Memory) – used to store permanent programs and data. Data stored in ROM is not erased when the MicroStamp11 is powered down, so programs that you save will still be in memory the next time you use the device. The MicroStamp11 has either 8k, 32k, or 64k of ROM, depending on the version of the MicroStamp11 purchased.•RAM (Random Access Memory) – used as a scratchpad to store variables during the execution of a program. Data stored in RAM is lost when the MicroStamp11 is powered down. The MicroStamp11 has only 256 bytes of RAM.Clock and Data Transfer RateThe MicroStamp11 is a digital synchronous device, meaning that all instructions are executed in synchronization with a hardware clock. The MicroStamp11 is available with either 8MHz or 9.8304 MHz (Turbo version) clock. Data can be transferred to the MicroStamp11 via the serial cable at either 9600 baud (bytes/second) or 38400 baud (Turbo version).The MicroStamp11 used in EGR 262 is the Turbo version with 32k of ROM Lab #8 EGR 270 – Fundamentals of Computer Engineering6Power SourceThe 68HC11 is powered by a 5V DC source. If a voltage of greater than 5V was connected to the microcontroller, it might be destroyed. The MicroStamp11 has a voltage regulator on the board to protect it.Operational Modes (sliding switches)The MicroStamp11 has two modes of operation. The modes are selecting by usingthe sliding switches on the side of the MicroStamp11 module. The modes are:•Boot mode – used when programs are downloaded to the MicroStamp11. Slide the two switches together to place the MicroStamp11 in boot mode.•Run mode – used when programs are run by the MicroStamp11. Slide the two switches apart to place the MicroStamp11 in run mode.Lab #8 EGR 270 – Fundamentals of Computer Engineering7Slide switches used to put the MicroStamp11 into boot mode or run mode68HC11 microcontroller5VregulatorCrystal - 8MHz or 9.834 MHz(looks like a silver cylinder)20 pins connected to the breadboard via the ribbon cableMicroStamp11 ModuleAssembler and SimulatorWe will program the MicroStamp11 using 68HC11 assembly language. Refer to class notes for details on assembly language programming. We will assemble programs using the Mini IDE assembler. We can also simulator programs using the Wookie simulator. Refer to the handout “Example: Mini IDE Assembler and Wookie Simulator” available on the instructor’s web page.Lab #8 EGR 270 – Fundamentals of Computer Engineering8DownloaderA program named MicroLoad is provided with the MicroStamp11 in order to download compiled C programs (S19 files) into the MicroStamp11.Lab #8 EGR 270 – Fundamentals of Computer Engineering9Input/Output Ports on the MicroStamp11The majority of the pins on the MicroStamp11 (see diagram below) are used for input and output so that we can communicate with the microcontroller. The input/output pins are arranged into two ports with the names:• PORTA (8 pins: PA0 through PA7 corresponding to pins 1-8)• PORTD (6 pins: PD0 through PD5 corresponding to pins 15-20)Lab #8 EGR 270 – Fundamentals of Computer Engineering10Logical Value and DirectionThe pins on each port have two distinct states:1) Logical State A. Logical 0 or LOW (0V)B. Logical 1 or HIGH (5V)2) Direction (the pin might be used as an input or as an output)A. IN (0)B. OUT (1)If a pin is configured as an output, then it acts like a 0V or 5V source (depending on the logical state) that can be applied to external circuits or devices connected to the pin.If a pin is configured as an input, then it acts like a HIGH resistance load and the MicroStamp11 can read the logical state of the pin applied by external circuits or devices connected to the pin.Lab #8 EGR 270 – Fundamentals of Computer Engineering11PORTDPORTD is a bi-directional register, so each pin may be configured as an input or as an output. The direction is controlled by the direction register DDRD.Hardware PinPORTD bitDirection Direction controlled by20 PD0 Bi-directional (input or output)Bit 0 of DDRD19 PD1 Bi-directional (input or output)Bit 1 of DDRD18 PD2 Bi-directional (input or output)Bit 2 of DDRD17 PD3 Bi-directional (input or output)Bit 3 of DDRD16 PD4 Bi-directional (input or output)Bit 4 of DDRD15 PD5 Bi-directional (input or output)Bit 5 of DDRDExample:DDRD (bit5 … bit0):PORTD (bit5 … bit0):1 0 0 1 0 0Result:PD0, PD1, PD3 & PD4 are inputs.PD2 & PD5 are outputs.PORTD and DDRD Addresses (see Table 4-1):In assembly language, we can set or clear bits in DDRD and PORTD by storing values at their memory addresses. For the MicroStamp11:PORTD address: $0008DDRD address: $0009Lab #8 EGR 270 – Fundamentals of Computer Engineering12Hardware PinPORTA bitDirection Direction controlled by6 PA0 Input only - - -7 PA1 Input only - - -8 PA2 Input only - - -5 PA3 Bi-directional (input or output)Bit 3 of PACTL4 PA4 Output only - - -3 PA5 Output only - - -2 PA6 Output only - - -1 PA7