In most of the Intel processors, the highest priority interrupt is the NMI line (called TRAP in the 8085). NMI means a non-maskable interrupt, and that means it cannot be delayed or ignored. The NMI line is usually used when there are problems such as non-recoverable errors, but it could be used for debugging or profiling.
Most of the Intel CPUs have 2 interrupt lines, the NMI line and the standard interrupt line. The regular interrupt line is connected to one or more interrupt controllers which split that interrupt signal to different devices. The NMI line is for the most critical processes in the computer.
The highest priority interrupt in the 8085 is the TRAP interrupt.
The lowest priority interrupt in the 8085 microprocessor is INTR, unless you also consider the software interrupts, RST 0 through RST 7, which are even lower.
It is an interrupt having highest priority in 8085
The peripheral with the highest interrupt priority depends on the hardware and software design of the particular system. In the 8085, the TRAP interrupt has the highest priority. The peripheral connected to TRAP is your choice.
when interrupts requests arrive from two or more devices simultaneously , the process has to decide which request should be serviced first and which one should delayed. the processor takes the decision with the help of interrupt priorities.
if u want to execute high priority interrupt,at that time of low priority running.So, we can mask the low priority interrupt and execute the high priority interrupt.
RSTn(0-7) is software interrupt & RST(7.5,6.5,5.5) are INTEL's 8085 maskable interrupts their priority is respectively 7.5,6.5,5.5.RSTn.5 is hardware intterrupt and it is controlled by the external pin available on the chip of 8085. it is used to interrupt the microprocessor from its normal execution and tends to execute some ISR(interrupt service routine)
TRAP is a non maskable interrupt pin in 8085.....it has the highest priority out of all the interrupts...it is used in emergency n critical states..ex.during power loss etc.
The TRAP interrupt is nomaskable in the 8085 microprocessor because TRAP is intended to indicate some serious system problem, or a hardware assisted debugger single step facility.
Four of the interrupts in the Intel 8085 (INTR, RST5.5, RST6.5, and RST7.5) are maskable, while one interrupt (TRAP) is non-maskable.The eight RSTx type of software "interrupts" are not really interrupts, but if they were treated as interrupts, they would be non-maskable.
RIM is Read Interrupt Mask. It is used to access the interrupt mask register, which contains the status of the three interrupt masks and the serial input data pin.
8085 is a microprocessor designed by Intel