Delay Time using 8085 Programming Loops 8085 Microprocessor by Ravinder Nath Rajotiya - October 13, 2021September 29, 20230 Delay Loops in 8085 Loop is used in 8085 for repeating the execution of a set of instructions. Loops are also used in generating the delays in 8085. The Loop is implemented by using the DCR and some conditional JMP instructions. A simple Loop is shown below MVI A, 00 MVI C, 05 Again: DCR C ADD C JNZ again This program make use of a add instruction inside a loop which executed five times. At the end of the loop addition of five numbers 0 to 5 is obtained which is 15. We can also use loop to generate delay time for some applications. The delay is actually the total ‘T’ states times the clock period. i.e. TL =
Arithmetic Instructions 8085 8085 Microprocessor by Ravinder Nath Rajotiya - December 14, 2020May 10, 20210 Arithmetic Instructions: The different instructions under this category are listed in table below: 1 ADDReg/Mem Adds accumulator with Reg or Memory word Acc ← Acc + Reg/Mem 2 ADC Reg/Mem Adds acc with carry to Reg or Memory Acc ← Acc + Reg/Mem + Cy 3 ADI 8-bit data Adds 8-bit immediate data to Accumulator Acc ← Acc + 8-bit data 4 ACI 8-bit data Adds with carry 8-bit data to Accumulator Acc ← Acc + 8-bit data + Cy 5 DAD Rp Add Register pair to HL HL ← HL + Rp 6 SUB Reg/Mem Subtract reg/Mem from accumulator Acc ← Acc + Reg/Mem 7 SBB Reg / Mem Subtract reg/Mem from acc with borrow Acc ← Acc – Reg/Mem - Cy 8 SUI 8-bit data subtract 8-bit data from acc Acc ← Acc – 8-bit data 9 SBI 8-bit data subtract 8-bit data from acc with borrow Acc ← Acc – 8-bit data - Cy 10 INR