JPH0777290B2 - Electronic circuit - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit, and more particularly, to an electronic circuit in which surface-mounted elements are mounted on a circuit board.

[Prior art]

A so-called jumper element may be used in an electronic circuit of a type in which various elements are mounted on a circuit board. The jumper element is an element that is installed on a predetermined land on the circuit board as needed and performs only a function as a jumper. The jumper element is used, for example, as a constituent element of a peripheral circuit that indicates the capacity of the mounted memory to the CPU side in an electronic circuit in which a memory can be added. Also, as an electronic circuit that can change the CPU clock frequency by installing an oscillator (clock) such as a crystal oscillator, as a peripheral circuit component that instructs the oscillator clock frequency to other circuits (for example, other CPUs). Used.

[Problems to be Solved by the Invention]

Since the conventional electronic circuit uses the jumper element having only the jumper function as described above, there is a problem that the number of elements of the entire electronic circuit is increased and the number of assembling steps is also increased. As a result, it has also been a factor in increasing costs. In addition, it was considered that the jumper was installed incorrectly in the electronic circuit assembly. Further, since the land for the jumper element has to be provided on the circuit board, there is a problem that the design of the land pattern and the wiring pattern on the circuit board becomes complicated. As a result, the actual packaging density of electronic circuits is also reduced. An electronic circuit of the present invention has an object to solve the above-mentioned problems and realize a jumper function without using a dedicated jumper element. The configuration of the present invention that achieves such an object will be described below.

[Means for Solving the Problems]

The electronic circuit according to claim 1 of the present invention comprises a circuit element such as a memory or an arithmetic element, and a surface of a resistor, a capacitor, an oscillating element or the like which is provided corresponding to the circuit element and constitutes a peripheral circuit of the circuit element. Equipped with a mounting element and a jumper pattern,
A setting circuit for setting an electrical state corresponding to the mounting state of the circuit element by non-connection, the circuit element and the surface mounting type element are mounted, and when the surface mounting type element is mounted, the surface mounting type And a circuit board in which the jumper pattern of the setting circuit is connected by at least one terminal portion itself connected to the internal circuit of the mold element. The electronic circuit according to claim 2 further includes: a memory element; a surface mount type capacitor that is mounted by being connected to a power supply line corresponding to the memory element; and when the memory element and the capacitor are mounted,
A circuit board constituting a memory module, comprising a jumper pattern as a part of the circuit board, and connecting / disconnecting the jumper pattern generates a signal corresponding to a mounting state of the memory element. The jumper pattern has an output setting circuit, and when the surface mount type capacitor is mounted, the jumper pattern is
The gist is that one of the jumper patterns is formed at a position where it is connected.

[Action]

The electronic circuit of the present invention having the above-described configuration is provided with a circuit element such as a memory or an arithmetic element, and corresponding to the circuit element,
The resistors, capacitors, and other components that make up the peripheral circuits of this circuit element.
A surface mount device such as an oscillator is mounted on the circuit board. On the circuit board, connect the jumper pattern /
By the non-connection, a setting circuit for setting an electrical state corresponding to the mounted state of the circuit element is formed. Then, when the circuit element and the surface mount type element are mounted, and the surface mount type element is mounted, the jumper pattern of the setting circuit is formed by at least one terminal portion itself connected to the internal circuit of the surface mount type element. The connection is established. That is, the terminal portion of the surface mount type element, which is required to form the peripheral circuit of the circuit element and has one terminal portion formed over a certain area, is connected / disconnected to the mounted state of the circuit element. The connection state of the jumper pattern is changed by arranging it in the jumper pattern of the setting circuit that sets the corresponding electrical state. In other words, one terminal portion of the surface mount device required for forming the peripheral circuit of the circuit device is connected to the internal circuit and plays its own role, and at the same time, the jumper of the setting circuit is used. It acts as a jumper element for connecting the patterns. The circuit element is a memory element, and the surface mount element is a capacitor that is mounted by being connected to the power supply line corresponding to the memory element. When these memory element and the capacitor are mounted, a memory module is configured. In an electronic circuit provided with a circuit board for performing the above, a setting circuit that outputs a signal for communicating the mounting state of the memory element to another electronic circuit may be required. Therefore, this setting circuit is configured to output a signal according to the connection / non-connection of the jumper pattern, and when a surface mount type capacitor is mounted, one terminal of this capacitor connects the jumper pattern of the setting circuit. With such a configuration, it is possible to reliably output a signal according to the mounting state of the memory element.

【Example】

In order to further clarify the configuration and operation of the present invention described above, preferred embodiments of the electronic circuit of the present invention will be described below. FIG. 1 is a perspective view showing a part of an electronic circuit as one embodiment of the present invention. This electronic circuit is a printed circuit board 1
And a RAM 2 and a bypass capacitor 3. RA
The M2 and the bypass capacitor 3 are temporarily fixed on the printed board 1, carried into an automatic soldering tank, and soldered to the printed board 1. The leads 21 of the RAM 2 are connected to the lands 41 formed on the printed board 1, respectively. On the printed circuit board 1, wiring patterns 6 connected between the lands 41 are formed.
Are formed. The bypass capacitor 3 is a surface-mounting type element, and terminal portions 31 and 32 formed on the entire circumference are provided on the surfaces of both ends thereof. These terminal parts 31, 32
Are connected to lands 51, 52, 53 formed on the printed circuit board 1. As shown, the first terminal portion 31 is connected to two lands 51, 52 separated from each other,
The second terminal portion 32 is connected to one land 53.
As will be described later, the first terminal portion 31 and the two lands 51, 52
And form a jumper pattern. The land 51 is grounded via another wiring pattern of the printed circuit board 1, and is also connected to the ground land 41 of the RAM 2 via the wiring pattern 6 as shown in the figure. Further, the land 53 and a power supply land (not shown) of the RAM 2 are connected to a power supply line for RAM (not shown) via a wiring formed on the printed board 1. The entire electronic circuit includes a large number of circuits in addition to the above, and the wirings thereof are arranged in a complicated manner, but they are omitted for convenience of illustration. FIG. 2 is a block diagram showing a strange configuration of the circuit portion shown in FIG. Bypass capacitor 3 is connected to RAM2 power supply VCC and ground potential GN.
It is connected to RAM2 in parallel with D. The bypass capacitor 3 prevents a decrease in the power supply voltage that is likely to occur during operation of the RAM 2, and thus the RAM 2 caused by the decrease in voltage.
It has a function to prevent the malfunction of. As described above, of the three lands 51, 52, 53 for the bypass capacitor 3, the first land 51 is grounded and the third land 53 is connected to the power supply VCC for RAM. Further, the second land 52 is connected to the power supply VCC at the connection point 7 via the pull-up resistor R1. When the bypass capacitor 3 is mounted, the first terminal portion 3 of the bypass capacitor 3 is located between the two lands 51 and 52.
They are connected by 1, and the potential V2 at the connection point 7 becomes the ground potential. Based on this potential V2, a signal indicating that RAM2 is mounted is given to the CPU (not shown). As a result, the CPU can recognize the memory space in which the RAM 2 is mounted and the memory space of the EMS and effectively use this memory space. On the other hand, if the bypass capacitor 3 is not mounted,
The potential V2 of the connection point 7 is raised by the power supply Vcc, and a signal indicating that the RAM2 is not mounted is given to the CPU based on this potential V2. That is, the first terminal portion 31 of the bypass capacitor 3 has a role as a jumper, and the bypass capacitor 3 also realizes a function as a jumper element. In this case, the first terminal portion 31 and the two lands 51, 5
With 2, the jumper pattern is formed. Further, the bypass capacitor 3 is a component of the peripheral circuit of the RAM 2 and is mounted only when the RAM 2 is mounted on the printed circuit board 1. Therefore, the jumper setting and the actually mounted structure of the RAM 2 are different. There is no such thing. Therefore, the reliability in assembling the electronic circuit is significantly improved. In an electronic circuit capable of mounting a plurality of RAMs, one bypass capacitor is provided for each RAM. Therefore, for example, in the case of adding one unit like a static RAM, a jumper pattern may be formed by each bypass capacitor 3 and the identification signal may be output for each RAM unit. Also a normal dynamic RAM
As described above, in an electronic circuit in which a predetermined number of RAMs are mounted as one set, one of the plurality of bypass capacitors mounted together with the one set of RAMs has only to function as a jumper. In this case, the potential of the connection point 7 in FIG.
The signal provided to the CPU based on V2 will indicate that the set of RAMs has been implemented. Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it goes without saying that the present invention can be implemented in various modes without departing from the scope of the present invention. For example, the present invention can be applied to an electronic circuit capable of changing the clock frequency of a CPU by installing an oscillator (clock) such as a crystal oscillator. In this case, the oscillator is a surface mount device, and the jumper pattern is formed by the terminal portion of the oscillator and the land on the printed board. Then, as in the case of the above-described embodiment, based on the signal generated according to this jumper pattern, a signal indicating the clock frequency of the oscillator is transmitted to another circuit (for example, another CP.
Given to U). The peripheral circuit including the jumper pattern is not limited to the circuit shown in FIG. 2 and may be any circuit generally having a jumper portion. In the above embodiment, as the surface mount element, an example of an electronic circuit using a capacitor was described, but the present invention is
It can also be applied to electronic circuits using other surface-mounted elements such as the above-described oscillation element and resistor. The terminal portion of the surface mount element does not have to be formed over the entire circumference thereof, and may be any terminal portion having a certain area such that two separated lands can be connected. In the example of FIG. 1 and FIG. 2, one terminal portion 31 forms a Japa pattern, but generally, when the surface mount element has a plurality of terminal portions, at least one terminal portion is a jumper. The pattern may be formed. Therefore,
It is also possible to utilize the terminal portions on both sides for forming the Japa pattern.

【The invention's effect】

As described above in detail, according to the electronic circuit of the present invention, at least one terminal portion of the surface mount type element which is provided corresponding to the circuit element and constitutes the peripheral circuit of the circuit element is connected / connected.
By arranging in the jumper pattern of the setting circuit that sets the electrical state corresponding to the mounting state of the circuit element by not connecting, one terminal part of the surface mount type element also serves as the jumper element for connecting the jumper pattern. is there. That is, instead of the dedicated jumper element, one terminal portion of the element, which is a surface mount element connected to the internal circuit and is necessary for the configuration of the electronic circuit, is used, and the number of components is reduced and the components accompanying it are reduced. Management, inventory control, and reduction of assembly man-hours are achieved. Further, since the surface mount type element provided corresponding to the circuit element is used for connecting the jumper pattern of the circuit, the connection / non-connection of the jumper pattern can be set surely corresponding to the mounting state of the circuit element. The setting error of the setting circuit is eliminated, and the function of the electronic circuit according to the mounting state of the circuit element can always be exerted. In particular, in a memory module that is a memory element of a circuit element and a surface-mounted element is a capacitor that is connected to a power supply line corresponding to the memory element, a jumper of the setting circuit is connected by one terminal of the surface-mounted capacitor. If the configuration of the present invention that brings the pattern into the connected state is adopted,
The connection of the jumper pattern of the setting circuit is also completed by the capacitor that is mounted as the memory element is mounted. Therefore, there is no possibility that an error will occur in the setting of the signal indicating the mounting capacity of the memory element to the outside, and all the memory elements mounted in the memory module can be used appropriately.

[Brief description of drawings]

FIG. 1 is a perspective view showing an electronic circuit as an embodiment of the present invention, and FIG. 2 is a block diagram showing an electrical configuration of the electronic circuit. 1 ... Printed circuit board, 2 ... RAM 3 ... Bypass capacitor 6 ... Wiring, 7 ... Connection point 21 ... Lead, 31,32 ... Terminal part 41,51,52,53 ... Land R1 ... Resistor for pull-up VCC ... Power supply

Claims (2)

[Claims] 1. A circuit element such as a memory or an arithmetic element, a surface mount element such as a resistor, a capacitor or an oscillation element which is provided corresponding to the circuit element and constitutes a peripheral circuit of the circuit element, and a jumper. A jumper pattern connection /
A setting circuit for setting an electrical state corresponding to the mounting state of the circuit element by non-connection, the circuit element and the surface mounting type element are mounted, and when the surface mounting type element is mounted, the surface mounting type An electronic circuit comprising: a circuit board in which the jumper pattern of the setting circuit is connected by at least one terminal portion itself connected to the internal circuit of the mold element. 2. A memory element, a surface mount type capacitor which is mounted corresponding to the memory element by connecting to a power supply line thereof, and when the memory element and the capacitor are mounted,
A circuit board constituting a memory module, comprising a jumper pattern as a part of the circuit board, and connecting / disconnecting the jumper pattern generates a signal corresponding to a mounting state of the memory element. The jumper pattern has an output setting circuit, and when the surface mount type capacitor is mounted, the jumper pattern is
An electronic circuit formed at a position where one of the jumper patterns is connected.