68HC11

No Description available.

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.

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.

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.

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.

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.

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.

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

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.