Global Synchronization??

ATI Radeon™ HD 5870 (“Cypress”) Architecture (2009) has Global Synhcronization. According to its specification:
2.72 Teraflops Single Precision,544 Gigaflops Double Precision

• Full Hardware Implementation of DirectCompute 11 and OpenCL™ 1.0
• IEEE754-2008 Compliance Enhancements
• Additional Compute Features:
• 32-bit Atomic Operations
• Flexible 32kB Local Data Shares
• 64kB Global Data Share
• Global synchronization
• Append/consume buffers

I searched for more information about it, examples in OpenCL, etc. but I didn't find. If you have any tips...write me.