Now let us see a program of Intel 8085 Microprocessor. This program is mainly for subtracting multi Byte numbers.Problem Statement:Write 8085 Assembly language program to add two multi-Byte numbers.Discussion:We are using 3-Byte numbers. The numbers are stored into the memory at location 8001H and 8004H. One additional information is stored at location 8000H. In this place we are storing the Byte count. The result is stored at location 8050H.We are taking the address of first operand block address into DE register pair, and the second operand block address into HL pair. The BC register pair is storing the destination address ... Read More

Light can be obtained from various sources like candles, lamp and sunrays etc. Light bulb had invented by Thomas Edison in 1879. An electric current is passed through a filament inside bulb, it gets heated up and emits light when sufficient current is passed through the filament. That means it converts electrical energy into heat energy in the bulb. Where in Light Emitting Diodes (LED), electronic electrical energy can directly converted into light energy.Light is a energy which is released by atoms. Particles of light are photons which have no mass. Atoms are basic building blocks which are made of small ... Read More

Let's discuss the Following two applicationsLow order address latchOutput port which is interrupting.Intel 8212 as low-order address latch − Here the low-order address lines and data lines are multiplexed and are available as AD7-0. It is convenient to have the address as many times and the separation of data on the different lines. Let's for an example, if we connect a chip like 2716 in an 8085-based system, the 2716 needs bit address of11 bits in its address pins, and here is separate 8 pins kept for data. Now connecting the AD7-0 pins of 8085 to the LS 8 address ... Read More

We use Intel 8212 in variety of applications. Let us discuss applications of 8212 in Mode 0It acts as buffer which is gatedBus driver which is Bi-directionalFor Interrupting the input portTo supply of eight instructions based on RST.Intel 8212 as gated buffer: A weak logic signal is converted to a strong logic when 8212 works in logic 0. The outputs of 8212 in mode0 is capable of sinking the 15 mA in 0 state, and which proves that a minimum high output voltage of nearly 3.65 V is in the state 1. Intel8212 is always given backup when the input ... Read More

The figure below shows the working of 8212 in mode 1Fig: Working of 8212 in mode 1We use this mode generally when we want 8212 to function as an output port. Here, microprocessor drives DI7-0, and the device at the output receives the information on Do7-0. The clock to the latches is provided in this mode. 8212 latches the information on DI7-0 when the CS makes transition from high to low. The CS signal gets activates when INT* is transferred by the interrupts by the driven data transfer scheme which is always performed when desired. The buffer at the output ... Read More

The below fig shows clearly how 8212 works in the mode 0Fig: 8212 working in mode 0We use this mode generally when we want 8212 to function like an input port. An input device gets connected to DI7-0, and the microprocessor employed here receives the information on DOs ranging from D7-D0. Here in this mode STB acts as clock for the given latches. The latch which is of 8 bits in 8212 follows the series information which is present on DI7 to DI0 as long as STB is equal to 1. When the STB makes a transition, which is high ... Read More

We find 8212 available in nowadays as a package chip which is dual inline having 24 pins total. We find its functional pin diagram below.Fig: Pin diagram of 8212 functionalFig: Pin diagram of 8212Voltage of + 5 V is required for it to work based on the supply which is DC. The latch which is 8 bit in 8212 receives the information which is present on the eight data inputs ranging from DI7 to D10. The condition which helps in information latching is present on DI7 to DI0 depends on the state of logic of the pin which is of ... Read More

There are two types of Input Output ports. They are Programmable Input Output ports and Non-Programmable Input Output ports. Since the functions of Programmable Input Output ports changed by software they became more popular. We don't need to change the wiring rather the hardware of the I/O port to change the function. Intel 8255 is a popular Input Output chip based on port. Whereas the I/O ports which are non-programmable needs to change the wiring or the hardware to change its complete function. We will see in later that the connection needs to be changed when 8212 works like an ... Read More

There are two types of Input Output ports. They are Programmable Input Output ports and Non-Programmable Input Output ports. Since the functions of Programmable Input Output ports changed by software they became more popular. We don't need to change the wiring rather the hardware of the I/O port to change the function. Intel 8255 is a popular Input Output chip based on port. Whereas the I/O ports which are non-programmable needs to change the wiring or the hardware to change its complete function. We will see in later that the connection needs to be changed when 8212 works like an ... Read More

In this program we will see how to exchange the content of DE and HL pair.Problem StatementWrite 8085 Assembly language program to swap the content of HL and DE register pair.DiscussionThis process is very simple, 8085 has XCHG instruction. This instruction swaps DE and HL pair content. We are storing some values to DE and HL pair directly, and then exchange them using XCHG.InputDE = 5678H HL = CDEFHFlow DiagramProgramAddressHEX CodesMnemonicsCommentsF00016, 56MVI D, 56HLoad D with56HF0021E, 78MVI E, 78HLoad D with78HF00426, CDMVI H, CDHLoad D with CDHF0062E, EFMVI L, EFHLoad D withEFHF008EBXCHGExchange the content of DE and HLF00976HLTTerminate the programOutputDE ... Read More