Method and apparatus synchronizing integrated circuit clocks

US8443225B2 · kind B2 · utility

Assignees

• Advanced Micro Devices, Inc. · US
• ATI Technologies ULC · CA

Inventors

• Aaron Nygren · Birkenfeld, DE
• Ming-Ju Edward Lee · San Jose, US
• Shadi M. Barakat · Sunnyvale, US
• Xiaoling Xu · Santa Clara, US
• Toan Duc Pham · Cedar Park, US
• Warren Fritz Kruger · Sunnyvale, US
• Michael John Litt · Toronto, CA

Key dates

• Filing date: Aug 13, 2012
• Grant date: May 14, 2013
• Expiry date: Aug 13, 2032

Classification

• Technology area (CPC G): Physics
• CPC primary: G11C7/1045
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

Embodiments described herein include a method and system for synchronizing clocks between coupled integrated circuits (ICs) in a computer system. According to an embodiment, a dedicated timing pin is provided on a first IC. The first IC configures a second IC to change a pin assignment, so that the second IC interprets a signal sent on the timing pin by the first IC and received on the reassigned pin as a request to transmit a return signal. The return signal is received on the timing pin. The return signal is used to determine whether timing should be adjusted by the first IC. In an embodiment a clock and data recover (CDR) circuit compares the signal sent to the signal received in order to make the determination. In an embodiment the first IC is a processor-based device, and the second IC is a memory device controlled by the first device.