8085 Clock Circuit: The 8085 has on chip clock generator. Fig. 4.1 shows the internal block diagram of the on chip clock generator. The internal clock generator requires tuned circuit like LC, RC or crystal, or external clock source as an … (Read More)

Memory Interfacing in 8085: Memory is an integral part of a microprocessor system, and in this section, we will discuss how to interface a memory device with the microprocessor. The Memory Interfacing in 8085 is used to access memory quite frequently … (Read More)

Input Output Interfacing 8085 Microprocessor: Any application of a microprocessor based system requires the transfer of data between external circuitry to the microprocessor and microprocessor to the external circuitry. User can give information to the microprocessor using keyboard and user can … (Read More)

Input Output Interfacing Techniques: The most of the microprocessors support isolated I/O system. It partitions memory from I/O, via software, by having instructions that specifically access (address) memory, and others that specifically access I/O. When these instructions are decoded by the … (Read More)

Input Output Transfer Techniques: In Input Output Transfer Techniques, the system requires the transfer of data between external circuitry and the microprocessor. In this section, we will discuss different ways of I/O transfer. Program controlled I/O or Polling control . Interrupt program controlled … (Read More)

Latching Circuit: We know that AD0 to AD7 lines are multiplexed and the lower half of address (A0 – A7) is available only during T1 of the machine cycle. This lower half of address is also necessary during T2 and T3 … (Read More)

Power on Reset Circuit in 8051: On reset, the PC sets to 0000H which causes the 8085 to execute the first instruction from address 0000H. For proper reset operation reset signal must be held low for at least 3 clock cycles. … (Read More)

Control Signals of 8085: The 8085 Microprocessor provides RD and WR signals to initiate read or write cycle. Because these Control Signals of 8085 are used both for reading/writing memory and for reading/writing an input device, it is necessary to generate … (Read More)