CN1009680B

CN1009680B - Circuit for selecting and locking in operation function circuitry

Info

Publication number: CN1009680B
Application number: CN 85103308
Authority: CN
Inventors: 波彻尔·鲁宾逊·休斯
Original assignee: Digital Equipment Corp
Current assignee: Digital Equipment Corp
Priority date: 1985-05-13
Filing date: 1985-05-13
Publication date: 1990-09-19
Also published as: CN85103308A

Abstract

The present invention is used in a data terminal device and comprises a microprocessor, wherein the microprocessor processes signals which are from both a main computer and a keyboard. The system of the present invention is provided with a plurality of operating function circuits, and a logic circuit is connected between the microprocessor and the operating function circuits; the logic circuit is provided with a first passage to allow signals generated according to commands from computers to pass through the first passage so as to select one operating function circuit, and the operating function circuit is switched to be 'On' and 'Off'. Besides, the logic circuit is also provided with a second passage to allow signals generated according to instructions from the keyboard to pass through the second passage so as to select one operating function circuit. The system also comprises a circuit which generates stopping signals so as to lock the operating function circuits.

Description

Circuit for selecting and locking in operation function circuitry

Use in the data handling system of data terminal equipment, a common operation is can make master data processor and terminal device open the back or close some have the operating function circuit.In the prior art, because this system has great flexibility,, but still can make the master data processor interrupt this function operations on a terminal device though this user that just can make at terminal device wants to continue a certain function of execution.For example, the smooth scroll of data display equipment is a kind of function of this class.The preemption of this Terminal Type operation often is a kind of interference source, and, can cause the loss of data in some cases.In the situation after, need playback of data.Circuit of the present invention is single only allows that data processor and keyboard open the operating function circuit or close, and if the keyboard operator thinks that selected operation must continue on terminal device, also tolerable comes locking master data processor with keyboard.

In the preferable embodiment of the present invention, microprocessor is connected on data processor and the keyboard.Microprocessor produces first and second data-signal.These signals are binary signals, and each data-signal is represented different instructions.When a sort signal deixis function circuit should turn-off, and another data-signal can indicate this function circuit to be unlocked.Microprocessor is according to the request or the instruction of keyboard, and perhaps request or the instruction according to processor produces first and second data-signal.Moreover microprocessor produces a plurality of first clock control signals from its primary processor, and each first clock control signal is represented the different circuit with operating function.Microprocessor also produces a plurality of second clock control signals according to the instruction from keyboard in addition.Every second clock control signal is also represented a different circuit with operating function.Logical circuit is connected to handles or receives first, second data-signal and clock control signal.When clock control signal is selected certain or is in " opening " or during the operating function circuit of " pass ", data-signal is selected " pass " and "open" state.In preferable embodiment, circuit of the present invention more comprises a bistable device.The connection of this device receives only data-signal and clock signal, and these signals only are the results of keyboard instruction.Above-mentioned bistable device can produce one and stop signal (im _pEdin _gSi _gNal), this stops the clock signal that signal stops the instruction according to principal computer to produce.Therefore, principal computer selects certain to be in or the ability of the operating function circuit of " opening " or " pass " can be by the command signal locking of keyboard.

By the description that the following drawings is separated, feature of the present invention and purpose just can be clearer.

Can see a principal computer 11 among the figure, it is connected to UART 15(universal asynchronous receiver/transmitter (UART) 15 by duplex channel 13).UART 15 is connected to microprocessor 19 by duplex channel 17.Microprocessor 19 is connected to keyboard 23 by passage 21.Some keyboard logic circuit 25 on the keyboard 23.Microprocessor 19 in the preferable embodiment is the T-11 that made by Digital Equipment Corporation, and keyboard is the LK201 that is made by Digital Equipment Corporation.This microprocessor 19 itself has the ability that produces binary data signal and a plurality of clock control signals.The binary number that is produced by microprocessor 19 binary one is according to this represented " opening ", and represents " pass " with binary zero.Binary data is transferred to " D " input end of each trigger 29,31,33,35,37 and 39 at passage 27.Trigger 29,31,33,35,37 and 39 is " D " D-flip flop, the 74LS74 type of making for Xi Neidisi company in preferable embodiment.Well-known is that " D " trigger can become by the indicated state of " D " input end when a clock signal (being connected to " C " input end) and " D " input signal occur simultaneously.What can understand is that passage 27 can have a traffic pilot, thus " D " signal that produces by principal computer just can with " D " Signal Separation that is produced by keyboard 23.In fact, the multipath conversion function is taken from the microprocessor 19.

By finding out among the figure, there are many lines 41 to be connected to microprocessor 19.Every line is designated and be connected to each different AND gate 43,45,47,49 and 51.Each AND gate 43,45,47,49 and another input end of 51 are from trigger 29.In "off" state, the current potential on online 53 is high as trigger 29.Can cause relevant AND gate to export a high voltage signal when therefore, high signal appears in arbitrary passage 41.What can understand is can use different voltage, and NOT-AND gate can replace AND gate to use, and also can use other forms of logic.This class changes all within the scope of the invention.

In addition, can see among the figure that many OR-gates 55,57,59 and 61 are arranged.Each OR-gate 55,57,59 and 61 links with relevant AND gate 43,45,47 and 49 output terminal.Therefore, if the input end of one of them AND gate 43 has the two-supremes signal, its output is high signal, and this signal can go to OR-gate 55, and to " C " input end of trigger 31.Can see among the figure that each OR-gate 55,57,59 and 61 has second input from microprocessor, and every incoming line receives from one of microprocessor 19 different clock control signal.For example,, thereby repeat logic 63 automatically or be " opening " or " pass " if trigger 31 is selected to opening, at this moment, to trigger 31 " D " just the signal of input end can correctly be selected (or " opening " or " pass " state).And line 65 just can be triggered by high voltage, produces high signal on online 67, transports to " C " input end of trigger 31.Command signal according to keyboard can produce identical operations and suitable clock control signal, and this class signal can online 69,71 and 73 finds.Thus.Keyboard just can select to have any in the circuit 63,75,77 and 79 of operating function.Equally, by selecting a suitable line 41, principal computer 11 can be selected arbitrary operating function circuit 63,75,77,79 and 81, and certainly, the output that the pairing AND gate 43,45,47,49 and 51 of this operating function circuit this moment is not triggered device 29 stops.Trigger 29 is to stop signal generator.As mentioned above, " C " input end of trigger 29 is connected to microprocessor 19, and with the control signal that the order that only receives by keyboard produces, " D " input end of trigger 29 then receives only " D " signal from keyboard instruction.Therefore, for example, if the use of keyboard 23 is when selecting smooth scroll logical circuit 75, and want to know that based on any reason principal computer does not disconnect the smooth scroll logical circuit, at this moment, the user can key in an instruction to microprocessor 19, to produce " connection " binary bit signal on a clock signal and one " D " input end on online 83.Thus, trigger 29 can go to " connection " state, and thereby online 53 on have a low signal, this signal can stop or each AND gate 43,45,47,49 and 51 of locking.When trigger 29 goes to " connection " side, principal computer 11 can not by " with " 43,45,47,49 and 51 the transmission any signal, thereby neither one operating function circuit 63,75,77,79 and 81 can be changed.

Be noted that trigger 39 is without any the input end from OR-gate.Thus, keyboard 23 just can not convert trigger 39 to " connection " side and the keyboard lockout logical transition is become " connection " state.By what above discussion and AND gate 51 may be obvious that be, principal computer can convert trigger 39 to " connection " state, thereby opens keyboard lockout logical circuit 81.What can understand is, keyboard lockout logical circuit 81 can be closed terminal device effectively, and its meaning is meant, if keyboard 23 is by locking, just terminal device can not be with in any data entry system.Based on some reason, user's desire of principal computer or principal computer keeps the information that will be transmitted.Thus, circuit of the present invention allows that just principal computer 11 blocks keyboard 23.On the other hand, if the keyboard user wants to know that his keyboard logic is to continue, he can deliver to instruction microprocessor 19, and this instruction meeting will make trigger 29 be in " connection " state.As to the description of other AND gates, AND gate 51 is understood by locking, thereby does not allow that principal computer 11 blocks keyboard 23.From the principle, system does not want to allow that keyboard blocks itself, and the circuit that is arranged (not arranging with OR-gate) is to guarantee that this situation is impossible.

Further as shown in circuit, provide a reset signal on the keyboard logic circuit 25 online 87, thus, when system during by presetting bit, each trigger 29,31,33,35,37 and 39 can go to the side that resets.

What can understand is, can use other logic element or firmware in the embodiment of the logic element such as AND gate OR-gate and trigger shown in the present, the logical operation that perhaps has at least a part to be finished by circuit shown in the figure is to finish by the program technic of microprocessor.More than all descriptions, all can in not breaking away from, make amendment by spirit of the present invention described in claims and scope.

Claims

1, in a terminal part, a keyboard (23) that produces command signal is arranged, this terminal part and the analytic accounting of the generation command signal machine (11) of calculating is worked in the lump; Also has a circuit in this terminal part, be used for selecting and the lock operation functional circuit, this circuit includes a microprocessor (19) that is connected on principal computer and the keyboard, this circuit is characterized in that, described microprocessor basis is from the on-off command signal of above-mentioned host computer or produce first control signal according to on-off or prevention command signal from above-mentioned keyboard in addition, produce second control signal according to above-mentioned prevention command signal from keyboard, produce first clock signal according to on-off command signal from above-mentioned principal computer, or, produce the second clock signal according to locking command signal from above-mentioned keyboard according to on-off command signal generation second clock signal from above-mentioned keyboard; This circuit also comprises a logical circuit (31 to 61), and this logical circuit is connected to microprocessor (19), is used for from wherein receiving first control signal and first, second clock signal; This logical circuit is connected to above-mentioned one first operating function circuit, is used for according to above-mentioned first control signal and first clock signal or controls the ON-OFF of aforesaid operations functional circuit in addition according to first control signal and second clock signal; This circuit comprises that also one stops signal generation apparatus (29), and this prevention signal generation apparatus is connected to above-mentioned microprocessor, is used to receive first and second control signals; This prevention signal generation apparatus also connects above-mentioned logical circuit, is used for exporting-stop signal according to above-mentioned first and second control signals and stops above-mentioned logical circuit.

2, in a terminal part, have one to be used to select circuit with the lock operation functional circuit according to claim 1, it is characterized in that described logical circuit comprises first (43,45,47,49, or 51), described first input end that has an input end and that is used to receive the locking signal to be used to receive first clock signal, above-mentioned first when not having above-mentioned locking signal, allow first clock signal pass through, and when above-mentioned locking signal occurring, stop above-mentioned first clock to pass through; This logical circuit also comprises second and first bistable device, this second has one to be connected to the input end that input end and that above-mentioned first output terminal is used for receiving above-mentioned first clock signal is used to receive the second clock signal, and these second goalkeeper, first and second clock signals therefrom transmitted; This first bistable device comprises that one is used to receive the input end of first control signal, one is used for receiving the output terminal that signal whichsoever and by second first and second clock signal that send is used to control the ON-OFF of the above-mentioned first operating function circuit; Thereby make described keyboard to stop signal to stop first ON-OFF that stops the aforementioned calculation machine to control the above-mentioned first operating function circuit by making by first.

3, in a terminal part, described being used for of with good grounds claim 2 selected and the lock operation functional circuit, it is characterized in that described first is AND gate.

4, in a terminal part, with good grounds claim 2 is described to be used for selecting and the circuit of lock operation functional circuit, it is characterized in that described second is OR-gate.

5, in a terminal part, with good grounds claim 2 is described to be used for selecting and the circuit of lock operation functional circuit, it is characterized in that described prevention signal generator is a bistable circuit.

6, in a terminal part, have one according to claim 2 be used for selecting circuit with the lock operation functional circuit, described operating function circuit comprises one second operating function circuit, is used for the locking keyboard, it is characterized in that:

Described logical circuit further comprises one the 3rd, and this Men Youyi input end connects the prevention signal that receives from stoping signal generator, and another input end responds from the keyboard lockout command signal of principal computer to microprocessor and receives the 3rd control signal; This logical circuit also comprises second bistable device, this device has an input end that is used to receive first control signal, be used to receive another input end of first clock signal, and be used to control the output terminal of the ON-OFF of the above-mentioned second operating function circuit, thereby, make this keyboard can stop principal computer to operate this keyboard by making the 3rd to be prevented from making keyboard by locking with above-mentioned prevention signal.

7, in a terminal part, being used to of with good grounds claim 2 selected the circuit with the lock operation functional circuit, it is characterized in that: above-mentioned first bistable device and prevention signal generator are D flip-flops, and this trigger has " D " input end and one " C " input end.

8, in a terminal part, being used to of with good grounds claim 7 selected the circuit with the lock operation functional circuit, it is characterized in that: described first control signal is transmitted to " D " input end of above-mentioned first bistable device, and described first and second clock signals are by first and second " C " input ends that alternately send above-mentioned bistable device to.