Priority access device with limit on query search
FIELD: computer science.
SUBSTANCE: device has n-byte query register, query limits location systems, each of which consists of counting timer and OR element, OR element, AND element, keys cascade.
EFFECT: higher reliability and speed of operation.
The invention relates to the field of computer technology, in particular to a device priority service requests. A device for the priority service requests , containing a register of applications, the input of which is connected to the information input device, the registers of priority items AND, OR, the counter, the outputs of which are connected with the first inputs of the circuits compare the outputs are connected to first inputs of elements And the first group, and the counting input of the counter is connected to the output element And the first inverted input of which is connected to the zero input trigger control, a single entrance through which the first element OR is connected to control inputs of the device with a single input counter and the pulse generator.
The disadvantage of this device is the limited functionality, because when a large number of differently prioritised applications waiting time applications with low priority is very large, which in some cases is illegal and may result in the loss of low-priority applications.
The purpose of the invention is to enhance reliability and performance of the device by reducing its hardware structure and improve the management of its work.
This object is achieved in that the device priority service register contains queries, dinnie inputs are connected to the inputs of the OR element and the input of the cascade of keys. The outputs of the element OR is connected with the first input element And the output of which is connected with a controlled input of the cascade of keys.
Diagram of the device shown in the drawing. Device priority access consists of a register of requests 1, item OR 2, the first key cascade 3, item OR system limitations finding applications 4, timer counter, system constraints query 5, the second key cascade 6, item And 7, the n-th key cascade of keys 8, the information input device 9, lines discharges queries 10, line installation 11, line resolution accepting 12, the information output device 13.
The device making the request priority service works as follows.
Isolated inputs bits of register requests 1 with information inputs 9 receives the service requests application, setting the appropriate bits of the register 1 in one state. From the output of register requests 1 signals queries, each on its own line, go to the inputs of an item OR 2. When there is at least one request in the register 1 output OR 2 is supplied to the first input element And 7, when ready processing device, as evidenced by the presence of a signal on the line resolution accepting 12, output And 7, the signal at the control input of the first key cascade 3, to the information inputs this is key 3 receives the signal from the inputs of the register of requests 1. Subject to the availability of the application, i.e. the installation of one of the bits of register requests 1 in one state and the enable signal of acceptance of the request, the managed entry of the first key cascade 3 will be a single signal that will ensure the passage of signals from the information inputs of the first key on its information outputs, if the request has the highest priority, then a single signal will pass through the line connecting the 1st exit key 3 with the information output device and a controlled input of the second key cascade 6, thus closing it, if the query had a lower priority, then the first output information output device 13 will be a senior. Thus a cascade of keys, in which each subsequent key in the discharge is less than the previous one, managed the input of the following key connected to the output of the high-order bit of the previous key, selects a single code corresponding to a request, which is formed on the information output device 13, also formed of a single code entered on the discharge line of 10 requests, setting to zero the corresponding bit of register requests 1, thereby preparing it for the next request of the same priority. In addition, using the system constraints of location queries, you can limit the finding of a request in the system, i.e. if for a certain period of time after the request is received in the device priority access it will not be serviced, this type of query will be reset. The system limits the location query comprises a timer counter 5, the signal input of which is connected with the corresponding output register requests 1, control inputs connected to lines installation 11, and the output associated with the element OR 4, which is located on the discharge line of the application of the relevant request, i.e. one input of the OR element 4 is connected with the output of the cascade of keys on a corresponding line of the reset request, and the second input is connected with the output of the timer counter 5, the output signal OR 4 resets the corresponding bit of register requests 1. The system limits the location query is that after the request signal has set the respective digit of the register query 1 in one state, a single signal from the corresponding output register query 1 is supplied to the signal input of the timer counter 5, in turn timer counter 5, which can be installed on various waiting time service request along the lines of installation 11 begins to decrease the value until reset, if the timer counter 5 is reset before the request is serviced, a single output signal from the timer counter 5 will go to one of the inputs element OR 4, at the output you receive a single signal, which resets the corresponding bit of register requests to zero, if the application BU the em serviced before the timer counter 5 is reset, the signals on lines 11 installation will put the timer counter 5 in the initial state. System limitations which may be installed on one of the queries can be several, or all, i.e. each request will have its system limits a request.
Thus, one cycle of operation of the device will be found in the request with the highest priority from coming to this point in time, and also ensures that the reset request with the time limit for service, if it was not serviced within a specified time.
In addition, during the cycle of operation of the device serves all applications, including low priority.
Thus the goal has been achieved.
1. USSR author's certificate No. 962948, CL. G 06 F 9/46, 1982.
The device priority of the access restriction of the location of the application containing n-bit register requests, a single input bits which is connected to the information input device, and outputs associated with the respective systems of the limitations of location requests, each of which consists of a timer-counter and element OR signal input of the timer counter corresponding system request restrictions connected with the corresponding output register requests, the control input of timerstate connected to the line installation, and the output is connected to the input element OR the given system constraints of location requests, a second input connected to a corresponding line of the reset request, the output signal of the element OR system request restrictions clears the corresponding bit of register requests, the outputs of the register of requests associated with the element OR the output of which is connected to the first input element And a second input connected to the line resolution of acceptance of the request, and the output is connected to the controlled input of the first key cascade of keys whose informational inputs connected to the outputs of register requests, the cascade of keys consists of n keys, with each key on the category of less earlier, the output of the high-order bit of the previous key is connected with a controlled input of the following key and an information output device, other information key outputs are connected to information inputs of the next key, in addition to n-th output of the n-th key is associated with an information output device, an information output device are connected with lines reset requests.