PC card controller circuit to detect exchange of PC cards while in suspend mode

A computer comprising:

• a CPU having at least two operating modes, one operating mode of the CPU being a normal operating-mode and another operating mode of the CPU being a lower power, Suspend operating-mode, the CPU responding only to a limited class of interrupt signals while operating in the Suspend operating-mode;
• and
• a PC Card controller including:
• a host-computer bus-interface adapted for exchanging digital signals, including interrupt signals, with a bus included in the computer, interrupt signals supplied to the bus of the computer by said host-computer bus-interface being received and processed by the CPU if the CPU is operating in the normal operating-mode;
• a PC Card interface-circuit for exchanging digital signals with a PC Card inserted into a PC Card socket included in the computer, during normal operation of the CPU said PC Card interface-circuit generating an interrupt signal for transmission to the CPU via said host-computer bus-interface upon insertion of a PC Card into the PC Card socket;
• a suspend/resume pin for receiving a suspend/resume signal which, in a first state of the suspend/resume signal, indicates that the CPU is not operating in the Suspend operating-mode, and which, in a second state of the suspend/resume signal, indicates that the CPU is operating in the Suspend operating-mode;
• and
• a fake PC Card-insertion-interrupt generator which, upon detecting a change in the suspend/resume signal from the second state to the first state, generates, for transmission to the CPU via said host-computer bus-interface, an interrupt signal that simulates insertion of a PC Card into the PC Card socket.

A method for operating a PC Card controller adapted for use in a computer which includes a CPU, the CPU having at least two operating modes, one operating mode of the CPU being a normal operating-mode and another operating mode of the CPU being a lower power, Suspend operating-mode, the CPU responding only to a limited class of interrupt signals while operating in the Suspend operating-mode, the method comprising the steps of:

• exchanging digital signals, including interrupt signals, between the PC Card controller and a bus included in the computer, interrupt signals supplied to the bus of the computer by the PC Card controller being received and processed by the CPU if the CPU is operating in the normal operating-mode;
• exchanging digital signals between the PC Card controller and a PC Card inserted into a PC Card socket included in the computer, during normal operation of the CPU the PC Card controller generating an interrupt signal for transmission to the CPU via the bus upon insertion of a PC Card into the PC Card socket;
• supplying a suspend/resume signal to a suspend/resume pin of the PC Card controller, the suspend/resume signal in a first state indicating that the CPU is not operating in the Suspend operating-mode, and in a second state indicating that the CPU is operating in the Suspend operating-mode;
• and
• upon detecting a change in the suspend/resume signal from the second state to the first state, generating, for transmission to the CPU via the host-computer bus-interface, an interrupt signal that simulates insertion of a PC Card into the PC Card socket.