JPH0528743A - Slot mounted card identifying device for electronic equipment equipped with two card slots - Google Patents

Abstract

PURPOSE:To reduce the number of signal terminals for identifying a mounted card by providing a slot-on terminal, and an option-on terminal and an option card enable terminal connected between slots, at each slot. CONSTITUTION:Each slot 1 and 2 is equipped with the slot-on terminal, option-on terminal, and option enable terminal for an option card enable signal generated at the time of mounting the option card such as an RAM. The option-on terminals, and the option enable terminals are respectively connected with each other between the slots 1 and 2. Then, each option card mounting signal and option card enable signal is processed at an AND gate, and an OR gate in the slots 1 and 2, so that a slot-on signal can be outputted, and the mounted card can be identified according to the ON and OFF of the option card enable signal. Thus, signal lines among the general boards can be shared by each slot, so that the number of the signal terminals can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device having a slot in which a card such as a font card or a RAM card can be mounted, and determines the type of card (normal card or option card) mounted in each slot. It relates to an identifying device.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional method for identifying the type of a card installed in an electronic device having two card slots. Here, there are two types of cards that can be installed, normal cards are font cards, and option cards that can be installed in place of normal cards are RAM cards. RAM as an option card
The card can output a RAM card-on signal when mounted in the slot. That is,
The slot 1 and the slot 2 are provided with a font card 1 ON terminal and a RAM card 1 ON terminal, and the slot 2 is provided with a font card 2 ON terminal and a RAM card 2 ON terminal. These four signals are led to the general purpose port,
It is put on the data bus and read out by the CPU. In the above configuration, when the font card is mounted in the slot 1, the font card 1 on terminal is turned on and the RAM card 1 on terminal is turned off. If a RAM card is installed in the slot 1, the font card 1 on terminal is turned on and the RAM card 1 on terminal is turned on. The same applies to slot 2. Therefore, the CPU can determine the type of the card mounted in each slot by observing the state of these four terminals. In addition, a RAM enable signal (R
AM EN), that is, a control signal for setting the RAM in the write mode when a RAM card is mounted in the slot (a bar WR signal may be used instead of the RAM enable signal).

[0003]

However, a total of four signal lines are required to identify the card, and the number of pins of the general-purpose port is also required accordingly.

It is an object of the present invention to provide a mounted card identifying device which can reduce the number of signal lines for identifying the card and the number of pins of a general-purpose port.

[0005]

FIG. 1 is a block diagram of the present invention.

As shown in FIG.
A slot on terminal, an option on terminal, and an option card enable terminal are provided. When compared with FIG. 2, the slot-on terminal corresponds to the font card-on terminal, the option-on terminal corresponds to the RAM card-on terminal, and the option card enable terminal corresponds to the RAM-enable terminal. A normal card corresponds to a font card and an option card corresponds to a RAM card. The option-on terminals of the two slots are connected to each other, and the option card enable terminals are also connected to each other. In each slot, when the normal card is installed, the slot-on terminal is unconditionally turned on by the OR gate, and when the option card is installed, the AND-gate is operated by the AND gate according to the option card enable signal. Are configured to turn on or off.

[0007]

When a normal card is mounted in slot 1 or slot 2, the slot-on terminal of each slot is unconditionally turned on. The option-on terminal is off.

Therefore, in this case, it can be immediately determined that a normal card is mounted in each slot. on the other hand,
If option cards are installed in both slots,
Alternatively, when the option card is attached to either one and the normal card is attached to the other, the option-on terminal is turned on and the slot-on terminals are in different states. When option cards are installed in both slots, the slot-on terminal of each slot depends on the option card enable signal. That is, if the option card enable signal is turned off, the slot on terminal of each slot is in the off state. Therefore, if the option card enable signal is off and the slot-on terminal of each slot is off, and the option-on terminal is on, it can be seen that both option cards are installed in both slots. On the other hand, if the option card is installed in either one and the normal card in the other, the normal card is installed in the slot whose slot-on pin is on when the option card enable signal is turned off, and It is possible to determine that the option card is installed in the slot of, that is, the slot in which the slot on signal is off.

In this way, after all, the cards mounted in the two slots can be identified by the two slot-on terminals, one option-on terminal, and one option-card enable terminal. Compared to FIG. 2, since the RAM enable signal of FIG. 2 corresponds to the option card enable signal of FIG. 1, four terminals are required in FIG. One slot-on terminal and one option-on terminal, that is, three terminals will suffice.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiments described below, the types of cards installed in each slot are a font card and a RAM card. The font card corresponds to the normal card of the present invention, and the RAM card corresponds to the option card.
The slot-on terminals in FIG. 1 correspond to slot 1 and are slot 1 on terminals, and those corresponding to slot 2 are slot 2 and on terminals. Although the RAM ON terminal corresponding to the option ON terminal of FIG. 1 is not shown, it is configured to turn on when a RAM card is mounted in each slot (a signal is formed by a pull-up resistor or the like so as to be “H”). It The option card enable signal of FIG. 1 is output from the general-purpose port as a RAM enable (RAMEN) signal.

3 and 4 show the connection states of the respective signal terminals when a font card is mounted in each slot and when a RAM card is mounted in each slot. Note that the RAM ON signal is omitted in these figures.

As shown in FIG. 3, when a font card is installed in each slot, the bar SLOT1 ON, S
LOT2 ON is turned on (“L” in negative logic). In this case, the on / off state of RAMEN is irrelevant. In addition, B has shown the 3-state buffer.

That is, the bar SLOT1 ON is SL
Turns off when no font card is attached to OT 1, and turns on when a font card is attached. Also, the bar SLOT2
ON is turned off when the font card is not attached to the slot 2 and is turned on when the font card is attached. In this case, each signal terminal is irrelevant to the state of RAMEN.

On the other hand, as shown in FIG. 4, RA is assigned to each slot.
When the M card is installed, it becomes as follows.

As shown in FIG. 4, the bar SLOT1 O
When a RAM card is attached to N and bar SLOT2 ON, a resistor R is connected and a signal of RAMEN is also connected. Therefore, bar SLOT1 O
N, SLOT2 ON is turned on or off by turning RAMEN on or off. Ie RAM
When EN is on, bar SLOT1 ON, bar SL
OT2 ON is always OFF (negative logic “H”) regardless of whether or not each RAM card is mounted. When RAMEN is off (“L” in positive logic), the bar SLOT1 O
The N, bar SLOT2ON is turned on or off depending on whether or not a RAM card is installed in each slot. That is,
When the RAM card is installed, the connection is as shown in the figure and the bar SLOT1 ON is turned on (negative logic "L").
When the RAM card is not installed, the bar S
LOT1 ON and bar SLOT2 ON are off (“H” in negative logic).

When the RAM card is mounted, the RAM ON signal (not shown) is in the ON state as described above.

FIG. 5 shows a flow chart for judging the type of the card mounted in each slot by the above-mentioned signal terminals.

This flow is executed, for example, when the power of the main body of the electronic device is turned on.

First, RAMEN is set to OFF and each slot-on signal is judged. If either slot 1 or slot 2 is on and the RAM on signal is on, it is determined that a RAM card is installed in each slot, and if there is no RAM on signal, a font card is installed. It is determined that it has been done. When the signals of the slots 1 and 2 are both off, it is determined that no card is attached to both slots.

On the other hand, when both the slots 1 and 2 are on and the RAM on signal is not output, it is determined that the font cards are installed in both slots.
Furthermore, when both the slots 1 and 2 are on and the RAM on signal is output, the state of each slot on signal is determined after turning the RAMEN on. If slot 1
If is turned on, it is determined that a font card is installed in slot 1 and a RAM card is installed in slot 2. If the slot 2 ON signal is output, it is determined that a RAM card is installed in slot 1 and a font card is installed in slot 2. If both slots 1 and 2 are off,
It is determined that RAM cards are installed in both slots.

By the above identification flow, the type of the card mounted in each slot can be surely determined.

As described above, in comparison with FIG. 2 showing the conventional configuration, since the conventional RAM card 1 ON signal and the RAM card 2 ON signal can be configured by one RAM ON signal, the conventional four signal terminals are provided. In the present embodiment, it is only necessary to use three lines, which was necessary.

[0023]

According to the present invention, the number of signal terminals for determining the type of the card mounted in each slot can be reduced.

[Brief description of drawings]

FIG. 1 shows a block diagram of the present invention.

FIG. 2 is a diagram for explaining a conventional method for identifying a mounted card.

FIG. 3 is a diagram showing a connection diagram when a font card is attached to each slot in the embodiment of the present invention.

FIG. 4 is a diagram showing a connection diagram when a RAM card is attached to each slot in the embodiment of the present invention.

FIG. 5 is a diagram showing a flowchart for identifying a card mounted in each slot in the embodiment of the present invention.

[Explanation of symbols]

SLOT1 ON, SLOT2 ON-Slot-on terminal RAMEN-RAM enable terminal (option card enable terminal)

Claims (1)

Claims: 1. A slot-on terminal, an option-on terminal that is turned on when the option card is installed, and an option card enable signal are provided on the control unit side in each of two slots in which a normal card or an option card is installed. An option card enable terminal sent from a device, the option on terminal and the option card enable terminal are respectively connected between the slots, when the normal card is installed, means for turning on the slot on terminal of the slot, A slot-mounted card identification device for an electronic device having two card slots, comprising means for turning on or off a slot-on terminal of the slot when the option card is mounted, according to the option-card enable signal.