Programmable timer module coupled to microprocessor system
US4161787A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 1977 |
| Grant date | Jul 17, 1979 |
| Priority date | — |
| Expiry date | Nov 4, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/0757
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A programmable timer module (PTM) is provided as a component of a microprocessor system in order to generate and measure varying time intervals under program control. The programmable timer module includes, in one embodiment, three independent 16-bit timers. Each timer includes a 16-bit counter and a 16-bit latch. The programmable timer module also includes an 8-bit status register and an 8-bit control register each of which may be coupled to an 8-bit bidirectional data bus of a microprocessor system. Selection circuitry is provided which permits the microprocessor to select either the control register or the status register. Information can be written into the control register; the operation is effected by means of read/write circuitry and a read/write input. Any one of the three timers can also be selected by means of the selection circuitry, and a 16-bit number can be written into the selected 16-bit latch. Reset circuitry resets the counter whenever the 16-bit latch is written into, and the counter counts until it reaches the number written into the 16-bit latch, whereupon the interrupt circuitry generates an interrupt signal and sets an appropriate interrupt bit in the status …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.