Method and apparatus for handling system management interrupts (SMI) as well as, ordinary interrupts of peripherals such as PCMCIA cards

摘要

An electronic system (100) includes a first integrated circuit (IC) (112) having a card system management interrupt (SMI) output pin (CRDSMI#) and interrupt pins (IRQ3-5), and a logic circuit (1620, 1630) having an output connected to the card SMI pin. This logic circuit further has inputs connected to a first and second set of registers and logic for first and second cards (CARD A,B) respectively. Each of the first and second sets of registers and logic include a first register (CSC REG) having bits set by at least a card event (CDCHG) and a battery condition event (BWARN) respectively. A logic gate (2672) responds to combine the bits from the first register. A second register (INT AND GEN CTRL REG) has a bit (SMIEN) for steering the output of the logic gate (2672) for ordinary interrupt or for system management interrupt purposes depending on the state of the bit (SMIEN). A second integrated circuit (110) has a system management interrupt (SMI#) output pin and SMI circuitry (2370) including a SMI register (2610) connected to events sources eligible for SMI response including the card SMI output of the first integrated circuit. This second IC (110) further has a mask SMI register (2620) connected to the SMI register (2610) to select particular ones of the events sources for SMI response. A logic circuit (2634, 2638) is fed by the SMI register (2610) for combining the selected events sources to supply an internal SMI output (SMIOUT). Other circuits, systems and methods are also disclosed.