The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 08, 1993
Filed:
Apr. 24, 1992
John W Jerrim, Duluth, GA (US);
Scott C Swanson, Roswell, GA (US);
Hayes Microcomputer Products, Inc., Norcross, GA (US);
Abstract
A status word modification device. A serial communications device (11) contains two universal asynchronous receiver transmitters (UARTs) (14, 15). Each UART contains a first in, first out (FIFO) buffer (14a), two status buffers (14b, 14c), and a FIFO control register (14d). If the applications program in the host (10) is an enhanced application program which supports the use of the FIFO buffer (14a), then the program will cause FIFO enablement instructions to be written into the control register (14d). In this case, the interface circuit (22) allows the status words to pass unaltered whenever the host (10) reads the status buffers (14b, 14c). However, if the applications program is a standard applications program which does not support the use of the FIFO buffer (14a), then the program will not write to the control register (14d). In this case, the interface circuit (22) will alter the value of selected bits of the status words if the user has enabled the FIFO buffer (14a) and the host reads the status buffers (14b, 14c). The alteration of the status word prevents the standard applications program from treating the FIFO-related bits in the status words as data errors.