Browse Prior Art Database

Multifunction Timer

IP.com Disclosure Number: IPCOM000088125D
Original Publication Date: 1977-Apr-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 3 page(s) / 64K

Publishing Venue

IBM

Related People

Cianciosi, MN: AUTHOR [+3]

Abstract

The multifunction timer is used to time functions given by a controller to workstations. The controller initiates commands and provides data to all workstations connected to it. The controller can control a plurality of workstations, and, therefore, it is desirable to time functions given to the workstations so as to maximize performance.

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Multifunction Timer

The multifunction timer is used to time functions given by a controller to workstations. The controller initiates commands and provides data to all workstations connected to it. The controller can control a plurality of workstations, and, therefore, it is desirable to time functions given to the workstations so as to maximize performance.

The multifunction timer utilizes the interrupt mechanism of the controller to provide the necessary timing intervals. The interrupts in the controller occur at preset times which are determined by a hardware counter. The count in the counter can be preset by a microcode instruction whereby discrete time intervals can be set according to the function being performed at a particular workstation. The transferring from main level microcode 10 to the interrupt level microcode 15 occurs in the controller when hardware counter 20 reaches a count of zero (Fig.
1).

Main level microcode supports functions that are initiated at the computer system level and passed to the workstation. Normally, these functions include read and write commands for data streams to or from the workstation to the system. The main level microcode also provides for translation of orders found in data streams and generally provides specific control functions for the workstations, such as cursor or display blinking, lighting indicators and unlocking keyboards, where the workstations have a display and keyboard.

The interrupt level microcode performs such functions as testing function counters, checking power status at the workstations, processing key strokes and saving and restoring registers.

The main level microcode in the controller, before starting a function with the workstation, presets a count in storage to time out the function to be started. This is illustrated by block 30 in Fig. 2. The main level microcode then initiates a function within the workstation (block 31). The main level microcode then polls the workstation (block 32) to see if the function has been completed by the workstation.

While the workstation is performing the function, the main level program is interrupted when the hardware counter 20 reaches a count of zero. The interrupt level microcode fetches the count set up in storage by the main level microcode (block 40 in Fig. 3). A test is then made to see if the cou...