EP0355243A1
Expired / Lapsed
EP
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High capacity timer arrangement
Assignee: International Business Machines Corp
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Filing: 1988-08-26
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Granted: —
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Expires: 2008-08-26
Abstract
Abstract A device for providing a large number of timers is disclosed which comprises a random access storage (11) whose locations are sequentially addressed by a cyclic counter (19). For setting a new timer, the timeout value (13) and a timer tag (17) are furnished to the high capacity timer. The timeout value is then added to the current contents of the cyclic counter to generate an address at which the timer tag is stored thus establishing a new timer. When during cyclic addressing, it is detected that the location just addressed is not empty, a timer has expired, an interrupt signal is generated, and the stored timer tag is returned. A specific time scale register (23) and a clock divider (25) are provided so that the resolution of the high capacity timer is easily selectable. To allow existence of several timers expiring at the same time, a special timer service with chainable timer control blocks (T-CB) is provided.
Inventors
- 👤 Roy Dr. Want
- 👤 Robin Dr. Williamson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 03:58
CPC Classifications
G; G04; G04G; G04G15/00; G04G15/006
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
164 words
Timer arrangement for furnishing a time interval expiration indication for each of plural individually identified timers, comprising - random access (RAM) timer storage means (11) having plural storage locations each for holding at least one timer tag identifying a timer; - means (19, 23, 25) for sequentially and cyclically addressing storage locations of said timer storage means and for giving a timer expiration indication when an addressed timer storage location contains a timer tag; - means (13, 17) for receiving in connection with a timer request, a timer tag and a timeout value representing a desired timeout interval, - means (20) for deriving, from the present timer storage location address held in said cyclic addressing means (19, 23, 25) and from said timeout value (17), a future address which will be accessed by said cyclical addressing means after a time interval represented by said timeout value; and - means (29) for storing said timer tag in the timer storage location having said future address.
Claim 2
Dependent Claim
164 words
Timer arrangement for furnishing a time interval expiration indication for each of plural individually identified timers, comprising - random access (RAM) timer storage means (11) having plural storage locations each for holding at least one timer tag identifying a timer; - means (19, 23, 25) for sequentially and cyclically addressing storage locations of said timer storage means and for giving a timer expiration indication when an addressed timer storage location contains a timer tag; - means (13, 17) for receiving in connection with a timer request, a timer tag and a timeout value representing a desired timeout interval, - means (20) for deriving, from the present timer storage location address held in said cyclic addressing means (19, 23, 25) and from said timeout value (17), a future address which will be accessed by said cyclical addressing means after a time interval represented by said timeout value; and - means (29) for storing said timer tag in the timer storage location having said future address.
Claim 3
Dependent Claim
40 words
Timer arrangement in accordance with Claim 1, characterized by - means (27, 33) for furnishing the stored timer tag from a cyclically addressed timer storage location for which said timer expiration indication was given, to a host data bus (31).
Claim 4
Dependent Claim
57 words
Timer arrangement in accordance with Claim 1, characterized in that - said cyclic addressing means (19, 23, 25) includes a cyclic counter (19) which is advanced at regular intervals by a timer clock signal (37), - said timeout value being a numeric value which represents the number of timer clock intervals corresponding to the desired timeout interval.
Claim 5
Dependent Claim
38 words
Timer arrangement in accordance with Claim 3, characterized in that - said future address deriving means (20) comprises an adder connected to the outputs of said cyclic counter (19) and of a register (13) holding said timeout value.
Claim 6
Dependent Claim
83 words
Timer arrangement in accordance with Claim 3, characterized in that - said cyclic addressing means (19, 23, 25) comprises a loadable time scale register (23), and divider means (25) connected to said time scale register and to a source (39) of a master clock signal, - said divider means scaling down the master clock pulses at a rate given by the contents of the time scale register and furnishing the scaled-down pulse sequence as timer clock signal (37) to said cyclic counter (19).
Claim 7
Dependent Claim
116 words
Timer arrangement in accordance with Claim 1, characterized in that - means (21, 33) are provided for returning a future address which is used to establish a new timer, as timer reference to a host data bus (31), that - an additional register (15) is provided for holding a received old timer reference which represents the address of a timer storage location assigned to an active timer and containing a timer tag, and that - means (21, 29) are provided for addressing, in response to a cancel timer signal (35F), the timer storage location identified by said old timer reference, for deleting the contents of said addressed timer storage location to thus cancel the respective timer.
Claim 8
Dependent Claim
81 words
Timer arrangement in accordance with Claim 1, characterized in that - active timer detecting means (27) are provided which are connected to the timer storage means for receiving the contents of an addressed timer storage location, for detecting whether said contents is different from zero, for furnishing an interrupt signal to a host signalling line (35H), and for furnishing the contents of the addressed location which constitutes a timer tag via respective transfer means (33) to a host data bus (31).
Claim 9
Dependent Claim
155 words
Method of operating the timer arrangement of Claim 1, comprising the following steps: - providing a timer service as interface between the timer arrangement and a user, - for setting a timer, sending a timer request with a timer identifier and a timeout value to said timer service, - establishing a timer control block (T-CB) in said timer service and storing therein said timer identifier, - sending from said timer service a timer request to said timer arrangement, with the address of said timer control block as timer tag and with said timeout value, - in said timer arrangement, storing the address of the timer control block as timer tag in a selected timer storage location, and returning the address of said selected timer storage location as intermediate reference to said timer service, and - in said timer service, storing the received timer storage location address as intermediate reference in the assigned timer control block.
Claim 10
Dependent Claim
31 words
Method in accordance with Claim 8, comprising the following additional step: - returning from the timer service, the address of the respective timer control block as timer reference to the user.
Claim 11
Dependent Claim
107 words
Method in accordance with Claim 9, comprising the following additional steps for cancelling a timer: - sending the timer reference for the respective timer to the timer service, - in the timer service, accessing the timer control block addressed by said timer reference and sending the timer storage location address which is the intermediate reference contained therein together with a cancelling request to the timer arrangment, and then deleting the contents of said timer control block, and - in said timer arrangement, upon receiving the timer storage location address which is the intermediate reference and the cancelling request, deleting the contents of the respective timer storage location.
Claim 12
Dependent Claim
108 words
Method in accordance with Claim 8, comprising the following additional steps: - in said timer arrangement when, for setting a new timer, a timer storage location is accessed which is already occupied: returning to the timer service, a chaining indication and also the timer tag which is stored in the respective timer storage location and which represents the timer control block of an older timer, - in the timer service, concatenating the newly established timer control block (T-CB2) and the older timer control block (T-CB1) identified by said returned timer tag, without entering a timer storage location address as an intermediate reference into the newly established control block.
Claim 13
Dependent Claim
85 words
Method in accordance with Claim 11, comprising the following additional steps: - setting, in each timer control block when it is established, an activity indicator to active status, - for cancelling a timer, sending the respective timer reference and a cancelling request from the user to the timer service, and - in the timer service, testing in the respective timer control block whether it has a chained status, and if yes, only changing the activity indication in said timer control block from active to inactive.
Claim 14
Dependent Claim
101 words
Method in accordance with Claim 8, comprising the following additional steps: - addressing the timer storage locations cyclically and sequentially at regular intervals, and when an addressed location contains non-zero data, sending an expiration indication and the contents of said addressed timer storage location as timer tag to the timer service, and deleting the contents of the respective timer storage location, and - in the timer service, accessing the timer control block designated by said timer tag, sending an expiration indication and the timer identifier stored in said timer control block to the user, and thereafter deleting said timer control block.
Claim 15
Dependent Claim
84 words
Method in accordance with claims 11 and 12, comprising the following additional steps: - in the timer service, when receiving an expiration indication and a timer tag from the timer arrangement, testing in the respective timer control block whether it is chained, and if it is chained, accessing all chained timer control blocks, returning a stored timer identifier to the user only from those timer control blocks in which the activity status is set to active, and thereafter deleting all chained timer control blocks.
References Cited (Backward Citations)
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