Electronic control apparatus having first microcomputer which forwards externally supplied updating data to a second microcomputer having a lower data receiving performance than the first microcomputer

• US 20060227606A1
• Filed: 03/22/2006
• Published: 10/12/2006
• Est. Priority Date: 03/22/2005
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Okamoto, Kazuya
• Granted Patent: US 7,684,926 B2
• Time in Patent Office: Days
• US Class Current: 365/185.110
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices

Abstract

An electronic control apparatus such as an ECU of a motor vehicle contains first and second microcomputers, with the first microcomputer having a substantially higher data receiving performance than the second microcomputer. Data for updating a ROM of the second microcomputer, transmitted to the first microcomputer from an external apparatus at a relatively high data rate, are temporarily stored in RAM by the first microcomputer and then transmitted to the second microcomputer at a rate which is appropriate for the receiving performance of the second microcomputer.

Claims

1. An electronic control apparatus comprising a first microcomputer and a second microcomputer, each of said first microcomputer and second microcomputer comprising an internally disposed rewritable type of non-volatile memory and internally disposed communication circuit means coupled to communication line means, and each of said first microcomputer and second microcomputer performing processing based upon data stored in said non-volatile memory thereof and being responsive to write-in data that are directed thereto, received via said communication circuit means thereof, for writing said write-in data into said non-volatile memory thereof, to update said data stored in said non-volatile memory thereof;

wherein;

said communication circuit means of said first microcomputer comprises a first communication circuit coupled via a first communication line to an external apparatus and a second communication circuit coupled via a second communication line to said second microcomputer, and said communication circuit means of said second microcomputer comprises a communication circuit coupled to said second communication line;

said first microcomputer further comprises a volatile memory and storage control means for storing, in said volatile memory, data that are directed to said second microcomputer and are received from said external apparatus via said first communication circuit and second communication circuit, and data forwarding means for reading out said data from said volatile memory and transmitting said data to said second microcomputer via said second communication line at a rate determined in accordance with a data receiving performance of said second microcomputer; and

said second microcomputer receives said data transmitted by said data forwarding means as write-in data, to be written into said non-volatile memory of said second microcomputer.

2. An electronic control apparatus according to claim 1, wherein said data forwarding means divides said data directed to said second microcomputer into a plurality of data blocks and successively transmits said data blocks to said second microcomputer, and wherein a maximum size for each of said data blocks is predetermined based upon said data receiving processing capability of said second microcomputer

3. An electronic control apparatus according to claim 2, wherein said second microcomputer transmits a handshake signal to said first microcomputer each time that a specific data acquisition status is attained by said second microcomputer, and wherein said data forwarding means of said first microcomputer successively transmits said data blocks in response to successive occurrences of said handshake signal.

4. An electronic control apparatus according to claim 1, wherein said first microcomputer comprises data conversion means for operating on said data that are directed to said second microcomputer, to convert said data into a format capable of interpretation by said second microcomputer, and wherein said data forwarding means transmits said data to said second microcomputer after said conversion has been performed.

5. An electronic control apparatus according to claim 1, wherein:

said first comparison receives said data directed to said second microcomputer together with corresponding address information, and said data forwarding means transmits said data together with said address information to said second microcomputer, and

said second microcomputer receives said data as write-in data, and writes said write-in data into a specific region of said non-volatile memory, with said specific region being specified by said address information.

6. An electronic control apparatus according to claim 1, wherein said first microcomputer comprises:

means for acquiring from said second microcomputer, via said second communication line, write-in data that have been previously received by said second microcomputer;

comparator means for comparing said write-in data acquired from said second microcomputer with write-in data received from said external apparatus; and

,

comparison result notification means for transmitting notification information concerning results of said comparison performed by said comparator means, to said external apparatus via said first communication line.

7. An electronic control apparatus according to claim 1, wherein said first microcomputer is responsive to receiving a transfer status notification command transmitted from said external apparatus via said first communication line for transmitting, to said external apparatus, information indicative of an operating status of said data forwarding means.