Microcontroller test board circuit 5

 Here are some photos of it after assembly:   The following is a photo of plugging in the 89C51 chip in the 51 series, or it can be 89C52 or other 51 series chips.   　   The function of the jumper JMP0: used for digital tube test units and running water lamp test units For conversion, when the short-connector is in position 12, the running light unit is effective, and when the short-connector is in position 23, the digital tube unit is effective. The function of jumper JMP1: used to control the enable of the output port of the driver chip 74LS244. When the short-circuit is in position 12, it is enabled. This is the default position of the test board. When the short-circuit is in position 23, all the outputs of 74LS244 are low level. , no longer controlled by the output of the microcontroller. The function of jumper JMP2: The default position is to short-circuit the short-circuit. The function is to connect the P0.0~P0.7 output to 8 10K pull-up resistors. After removing it, the 8 output ports of P0.0~P0.7 will Disconnect from the pull-up resistor. The function of jumper JMP3: determines whether 24C02 and PCF8563 are connected to P1.6. Unplugging disconnects. The function of jumper JMP4: determines whether the N pole of the four fast switching tubes IN4148 connected to the keyboard is connected to P3.3. Unplugging disconnects. The above jumper position settings are suitable for different experiments. Once you become proficient, you can flexibly combine and set them up to maximize the power of the test board.