JPS62210721A - Semiconductor signal line replacing circuit - Google Patents

Abstract

PURPOSE:To replace signal lines by crossing the 1st and 2nd plural signal lines and arranging a semiconductor element having the gate of the equi-potential with the floating gate of a variable PROM to all cross points thereby allowing each variable PROM to select ON/OFF memories. CONSTITUTION:Semiconductor elements Tr1-Tr9 are inserted respectively to the cross points of respective signal lines in a replacing circuit replacing the 1st signal lines A-C into the 2nd signal lines (a)-(c) and floating gates EEPROMP1-P9 are connected respectively to gates of the semiconductor elements. When a positive charge is stored in the floating gate FG of the EEPROM P, the gate acts like an ON memory and when a negative charge is stored therein, the gate acts like an OFF memory. Since the floating gate FG is of equi-potential with the gate G of the semiconductor element Tr, when the connected EEPROM acts like the ON memory, the semiconductor element is conductive, and at the time of acting like the OFF memory, the element is nonconductive. That is, the constitution change of the signal line replacing circuit is much facilitated by rewriting the EEPROM memory.

Description

[Detailed Description of the Invention] [Summary] A semiconductor device in which a plurality of first signal lines and second signal lines intersect in a matrix pattern, and each intersection has a gate at the same potential as a floating gate of a variable PROM. , and select either ON or OFF memory for each variable PROM. In this way, a signal line switching circuit is obtained in which any of the second signal lines can be selected from each of the first signal lines.

[Industrial application field] The present invention relates to a semiconductor signal line selection circuit.

The development of information processing technology used in computers, word processors, etc. has been remarkable, and all of them are performed by processing digital signals.

Therefore, although digital technology has rapidly become widespread, there is a demand for variable circuits that allow users to reconfigure these information processes.

[Problems to be Solved by the Prior Art and the Invention 1] As is well known, there is an extremely large amount of signal data for information processing, and the number of signal lines ranges from hundreds to thousands.

Therefore, a switching circuit is required to switch the signal lines.
They are usually made in matrix form.

Figure 3 shows a simple switching circuit, and this example is a switching circuit that switches the first signal lines A, B, and C to the second signal lines a, b, and c. A diode D is inserted at the intersection of the required signal lines. That is, in this example, the first
This is a fixed circuit of a switching circuit that switches the signal line A to the second signal line a, the first signal line B to the second signal line S, and the first signal line C to the second signal line C.

On the other hand, with such a configuration, it is also possible to connect a switch element to each intersection and selectively operate the switch element to select any second signal line from any first signal line. Since the entire circuit becomes too complicated, a circuit with fixed switching lines is also provided as described above.

However, in such a fixed switching circuit, there may be cases where it is desired to change the configuration of the switching circuit. For example, from the first signal &iA to the second signal line a
The logic circuit Q connected to the second signal line c calculates the AND of the signal data of the second signal vAb from the first signal line B, and the signal data of the second signal vAb from the first signal line B. This is the case, for example, when the logical circuit Q wants to calculate the AND of the signal data from A to the second signal line a and the signal data from the first signal line C to the second signal line C.

In that case, conventionally the position of the diode D has been replaced. In other words, soldering involves replacing the diode.

However, this requires a large number of man-hours, and soldering in a complicated wiring bundle is a process that is likely to result in wiring errors.

The present invention proposes a changeable signal line switching circuit to eliminate such drawbacks.

[Means for solving the problem] The purpose is to configure a plurality of first signal lines and a plurality of second signal lines in a matrix, and to connect all the intersections between the first signal lines and the second signal lines. , by arranging a semiconductor element having a gate connected to the floating gate of the variable PROM and set to the same potential, and allowing each of the variable PROMs to select ON and OFF memories, each of the plurality of first signal lines is connected to the plurality of first signal lines. This can be achieved by a semiconductor signal line switching circuit that allows each of the second signal lines to be selected.

[Operation] That is, in the present invention, a plurality of first signal lines and a plurality of second signal lines intersect, and a semiconductor element having a gate set to the same potential as the floating gate of the variable PROM is arranged at all of the intersection points. , selects ON or OFF memory for each variable PROM.

Then, depending on the memory selection of the variable PROM, the first
Any of the second signal lines can be selected and connected from each signal line.

[Example] Hereinafter, embodiments will be described in detail with reference to the drawings.

FIG. 1 shows a signal line switching circuit according to the present invention, and this example is an extremely simple example corresponding to FIG. 3. That is, in a switching circuit that switches first signal lines A, B, and C to second signal lines a, b, and c, semiconductor elements Trl to Trg are inserted at the intersections of the respective signal lines, and the semiconductor elements are The gate is equipped with an EEPROM (memory whose memory can be changed electrically: Electric Eras).
(Programmable ROM)
The floating gates of M, -M, are connected.

Figure 2 shows the circuit diagram of the EEPROM.
c is a power supply, P is an EEPROM element, and S is its transfer 1 gate element (selection element).

If + charge is accumulated in the floating gate FG of such an EEPROM element P, it becomes an ON memory, and if + charge is accumulated in the floating gate FG, it becomes an OFF memory, but these floating gates FG are semiconductor elements. Since it is connected to the gate G of the Tr and has the same potential, when the connected EEPROM is an ON memory, the semiconductor element is in a conductive (low resistance) state, and when it is an OFF memory, the semiconductor element is cut off ( high resistance) state.

In addition, the method for rewriting EEPROM (n-channel type) memory is to change the power supply Vcc to a high voltage (for ON memory).
20 to 25■), turn on S, set the control gate CG of P to zero voltage, and turn on the floating gate 1-
Store + charge in FG. Further, in the OFF memory, the power supply VCC is set to zero voltage, S is turned on, the P control gate (CG) is set to a high voltage, and -charge is stored in the floating gate FG.

In this way, as shown in FIG.
If p51 p9 is an ON memory and other memories are OFF memories, the semiconductor element ↑rl * Tr
5 +Trg becomes conductive, and other semiconductor elements T
r becomes cut off. Then, from the first signal line A to the second signal line a, and from the first signal line B to the second signal line.

A switching circuit that switches the first signal line C to the second signal line C is created.

Then, for example, when changing the connection from the first signal line A to the second signal line A, P2 connected to the intersection of both signal lines is set to ON memory, and Tr2 is made conductive. In this way, the configuration of the signal line switching circuit can be changed extremely easily by rewriting the EEPROM memory.

In addition, instead of EEPROM+7), EPROM (memory whose memory can be changed by irradiating ultraviolet rays: Eras)
A similar variable changeover circuit can also be created using a flexible programmable ROM.

However, in that case, the EPROM is a PROM that is erased by ultraviolet light.
Therefore, when erasing the memory, there is no need for electrical operation, and the transfer gate element S becomes unnecessary.

[Effects of the Invention] As is clear from the above description, according to the present invention, a variable switching circuit can be obtained, which is conveniently useful for configuring an information processing circuit.

[Brief explanation of drawings]

FIG. 1 shows a signal line switching circuit according to the present invention, FIG. 2 shows its EEPROM circuit, and FIG. 3 shows a conventional signal line switching circuit. In the figure, A, B, C are first signal lines, a, b, c are second signal lines, D is a diode, Q is an AND circuit, Tr, 'I
rl to Trg are semiconductor elements, P1 to P9 are EEPRO
M. P is an EEPROM element, S is a transfer gate element, Vcc is a power supply, PG is a floating gate of P, CG is a control gate of P, and G is a gate of Tr. fJ! 11 Figure EEPROM circuit diagram 2

Claims (1)

[Claims] A plurality of first signal lines and a plurality of second signal lines are configured in a matrix, and all intersections of the first signal lines and second signal lines are connected to floating gates of a variable PROM to have the same potential. Each of the plurality of second signal lines can be selected from each of the plurality of first signal lines by arranging a semiconductor element having a gate and allowing each of the variable PROMs to select ON and OFF memories. A semiconductor signal line switching circuit featuring: