68HC11

This is a simple display controller. It can be controlled with a small microcontroller, such as MCS51, 68HC11, Z80, AVR and others. Several years ago, I found an article that controlling a TV with only a PIC micro controller, and I surprised to it. It is very interesting to attempt to synthesize video signal with a micro controller.

The MiniBoard, a Motorola 68HC11 Robot Controller board designed by Fred G. Martin, also uses this driver. The day after, I then decided to prepare the page describing how to use C-52 EVB as a robot controller board. I asked my student for competition, build yourselves robot that can track the black tape. Prize for the winner is 100 US$, with a bit condition that the winner must pay for a big party at Soi Jinda's Somtum (Papaya Salad) shop. And one of the competitor is me. I thought the rule should be conceived roughly by students and technically by me. The picture on that day will put here soon.

Using the circuit in Fig 1, a 68HC11 µP's stop instruction can put the µP's external RC-oscillator clock, as well as the µP itself, into a low-power mode. On receiving an interrupt, the µP will exit the stop condition and enable the RC clock. The RC clock, being a low-Q circuit, will start up immediately. Crystal oscillators, on the other hand, can waste precious milliseconds coming up to speed and stabilizing.

Figure 2 shows a block diagram for this sine-wave generator. You can easily analyze the generator's behavior by writing state equations in the z domain. You can also write equations in the s domain. The location of the two poles on the right-hand side reveals the generator's oscillatory nature. The inverse Laplace transformation is simple and results in a sine-wave statement.

There are many different microcontrollers on the market today that are being used in embedded control applications. Many of these embedded control systems need non-volatile memory. Because of their small footprint, byte level flexibility, low I/O pin requirement, low power consumption and low cost, Serial EEPROMs are a popular choice for non-volatile storage.

Using the circuit in Fig 1, a 68HC11 µP's stop instruction can put the µP's external RC-oscillator clock, as well as the µP itself, into a low-power mode. On receiving an interrupt, the µP will exit the stop condition and enable the RC clock. The RC clock, being a low-Q circuit, will start up immediately. Crystal oscillators, on the other hand, can waste precious milliseconds coming up to speed and stabilizing. The external RC oscillator uses simple Schmitt-trigger CMOS inverters.

This algorithm uses steps in the form of n/m, where n is an integer multiplier that is not a power of 2 and m is an integer that is a number with a power of 2. Making n and m relatively independent allows you to accurately set the number of samples in one cycle. When n is larger than 255, multiplying by n using 8-bit is time consuming. This algorithm allows n to be as high as 215 and the results to be as high as 231. Division by m is easy and fast because you simply left shift the register value. The overall operating principle is to keep these values as integers to avoid using floating-point arithmetic. The resultant assembler routine is simple and fast.

The cross compiler works on any host supported by GNU tools (Solaris, GNU/Linux, FreeBSD, HP/UX, MacOS X, Windows,...).

A simple schematic for 68HC11 or 68HC811 in Bootstrap-Mode. MODA and MODB = 0 Volt. The RS232-circuit has a automatic RESET-circuit. My assembler ASY.EXE send a BREAK-Signal with 110.

other circuits:decode, eprom ram and LCD.

Transmit-program in assembler 68HC11 expanded board with CAN BUS. The 68HC11 with CAN-CONTROLLER 82527 from Intel.

No Description available.

This source code is for 68HC811 with 2048 Bytes EEPROM. The board with 68HC811 must be in BOOTSTRAP-MODE.

This is an image Schematic. No Description available.

The software can load every program in the internal EEPROM (68HC11A1 and 68HC11811) and execute it step by step. The board must be in BOOTSTRAP-MODE.

With the HC11 board you will see all the advantages of the MC68HC11. The control of any LCD, a menustructure, the saving of data in the internal EEPROM, the application of SPI and SCI and many more. You will learn these and more using this card.

The Eprom emulator BYTERUNNER emulates the following Eprom types: 27C32(4K) 27C64(8K) 27C128(16K),27C256(32K)and 27C512(64K).

The Eprom Emulator EE16 is nothing else than two single eprom emulators connected to the same flat cable. The binary or Hex-file will be uploaded automatically to the eprom emulator EVEN and the eprom emulator ODD. The upload-time for 2 * 64k of data is absolved lesser than 1 second, witch is very fast and of course much faster than every serial-based device.

This is an image Schematic. No Description available.

The encoder is connected to PORTA PA0 and PA1 The board must be in BOOTSTRAB MODE (tested with Loggyboard).