Patent ID: 6108751
Filing Date: 2000-08-22
Classification: G06F,G06K,G11C

Abstract:
A method for data communication by serial block transfers of data on a single data line between first and second systems, comprising the steps of:defining the current operating mode to be either a write mode, in which data is transferred from said first system to said second system, or a read mode, in which data is transferred from said second system to said first system; and thereafter, for each bit of data in a single block transfer,initially, in said first system, driving the data line toward a first voltage, and thereafter driving the data line to make a transition toward a second voltage;detecting, in said second system, said transition of said data line toward said second voltage;and, in said read mode,in said second system, conditionally driving said data line toward said second voltage, depending on the data bit being read, for a first time duration which is substantially predetermined for a given one of said second systems, and then floating said data line, andin said first system, testing the state of said data line within a time window which terminates before the minimum possible duration, for said second system, of said first duration;and, in said write mode,in said first system, driving said data line toward a data voltage, which is more nearly equal to one of said first and second voltages in accordance with the data bit being written;in said second system, waiting for a second time duration which is substantially predetermined for a given one of said second systems, and then testing said data line to ascertain the data value being written; andin said first system, holding said data line to said data voltage over a time window which begins before the earliest possible expiration, for said second system, of said second duration, and which ends after the latest possible expiration, for said second system, of said second duration.