Method of transferring signals within electronic control system for internal combustion engines

Claim 1

A method of transferring at least one signal between a first central processing unit provided in an electronic control system for controlling fuel supply to an internal combustion engine and a second central processing unit provided in said electronic control system for controlling ignition of a mixture supplied to said engine, wherein a value of at least one operating parameter of said engine is detected, and the detected value of said at least one operating parameter is used both for controlling the fuel supply to said engine and for controlling the ignition of the mixture supplied to said engine, the method comprising the steps of: connecting at least one signal transfer line between said first and second central processing units; causing said first central processing unit to produce a digital signal representing the detected value of said at least one operating parameter; causing said first central processing unit to produce data consisting of a predetermined number of bits as said digital signal; causing said first central processing unit to send a transfer instruction signal to said second central processing unit when said first central processing unit is in a background state wherein a calculation of fuel supply amount is not being carried out; causing said second central processing unit to send an acknowledgement signal to said first central processing unit to initiate a transfer of said data to said second central processing unit when said second central processing unit is in a background state wherein a calculation of ignition timing is not being carried out; causing said first central processing unit to start in response to said acknowledgment signal to transform said data by serializer means into a sequence of pulses, each pulse corresponding to a respective one of said bits, and to transfer said pulses one by one to said second central processing unit through said signal transfer line in a start-stop serial manner, said serializer means being operated in synchronism with a first clock signal; and causing said second processing unit to transform said sequence of pulses transferred to said second processing unit back into data consisting of said predetermined number of bits by deserializer means, said deserializer means being operated in synchronism with a second clock signal which is asynchronous with said first clock signal but has the same pulse repetition period as said first clock signal, said second central processing unit being able to send a request instruction signal to said first central processing unit for requesting said first central processing unit to transfer data thereto.

Claim 2

A method of transferring at least one signal between a first central processing unit provided in an electronic control system for controlling fuel supply to an internal combustion engine and a second central processing unit provided in said electronic control system for controlling ignition of a mixture supplied to said engine, wherein a value of at least one operating parameter of said engine is detected, and the detected value of said at least one operating parameter is used both for controlling the fuel supply to said engine and for controlling the ignition of the mixture supplied to said engine, the method comprising the steps of: connecting at least one signal transfer line between said first and second central processing units; causing said first central processing unit to produce a digital signal representing the detected value of said at least one operating parameter; causing said first central processing unit to produce data consisting of a predetermined number of bits as said digital signal; causing said first central processing unit to send a transfer instruction signal to said second central processing unit when said first central processing unit is in a background state wherein a calculation of fuel supply amount is not being carried out; causing said second central processing unit to send an acknowledgement signal to said first central processing unit to initiate a transfer of said data to said second central processing unit when said second central processing unit is in a background state wherein a calculation of ignition timing is not being carried out; causing said first central processing unit to start in response to said acknowledgment signal to transform said data by serializer means into a sequence of pulses, each pulse corresponding to a respective one of said bits, and to transfer said pulses one by one to said second central processing unit through said signal transfer line in a start-stop serial manner, said serializer means being operated in synchronism with a first clock signal; and causing said second processing unit to transform said sequence of pulses transferred to said second processing unit back into data consisting of said predetermined number of bits by deserializer means, said deserializer means being operated in synchronism with a second clock signal which is asynchronous with said first clock signal but has the same pulse repetition period as said first clock signal, said second central processing unit being able to send a request instruction signal to said first central processing unit for requesting said first central processing unit to transfer data thereto.