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The 8085 has extensions to support new interrupts, with three maskable vectored interrupts (RST 7.5, RST 6.5 and RST 5.5), one non-maskable interrupt (TRAP), and one externally serviced interrupt (INTR). Each of these five interrupts has a separate pin on the processor, a feature which permits simple systems to avoid the cost of a separate ...
The 8085 has a TRAP interrupt which cannot be disabled (that is, TRAP is a Non-Maskable interrupt or NMI) and an INTR interrupt. Comprehensive use of the INTR requires an external Programmable Interrupt Controller such as an Intel 8259."
A hardware interrupt is a condition related to the state of the hardware that may be signaled by an external hardware device, e.g., an interrupt request (IRQ) line on a PC, or detected by devices embedded in processor logic (e.g., the CPU timer in IBM System/370), to communicate that the device needs attention from the operating system (OS) [7] or, if there is no OS, from the bare metal ...
FLAGS registers can be moved from or to the stack. This is part of the job of saving and restoring CPU context, against a routine such as an interrupt service routine whose changes to registers should not be seen by the calling code. Here are the relevant instructions: The PUSHF and POPF instructions transfer the 16-bit FLAGS register.
32-bit interrupt return. Differs from the older 16-bit IRET instruction in that it will pop interrupt return items (EIP,CS,EFLAGS; also ESP [ j ] and SS if there is a CPL change; and also ES,DS,FS,GS if returning to virtual 8086 mode ) off the stack as 32-bit items instead of 16-bit items.
The descriptors may be either interrupt gates, trap gates or, for 32-bit protected mode only, task gates. Interrupt and trap gates point to a memory location containing code to execute by specifying both a segment (present in either the GDT or LDT) and an offset within that segment. The only difference between trap and interrupt gates is that ...
A status register, flag register, or condition code register (CCR) is a collection of status flag bits for a processor.Examples of such registers include FLAGS register in the x86 architecture, flags in the program status word (PSW) register in the IBM System/360 architecture through z/Architecture, and the application program status register (APSR) in the ARM Cortex-A architecture.
In computing, a non-maskable interrupt (NMI) is a hardware interrupt that standard interrupt-masking techniques in the system cannot ignore. It typically occurs to signal attention for non-recoverable hardware errors. Some NMIs may be masked, but only by using proprietary methods specific to the particular NMI.