AMD has just released a massive 392-page PDF reference guide on its R700-family Instruction Set Architecture (or RV700 GPUs) dated March 2009. The guide includes documentation for various ATI GPUs in the R700 family:

RV710 (Radeon HD 4350/4550)
RV730 (Radeon HD 4650/4670)
RV740 (Radeon HD 4750/4770)
RV770 (Radeon HD 4830/4850/4870)
RV790 (Radeon HD 4890)

More importantly, the guide serves to specify the instructions of the R700 architecture as well as the format of these instructions. This will provide guidelines for programmers and compiler writers to maximize processor performance. In other words, let's hope developers jump on this new documentation, as all too often the answer to a problem is already in data sheets like these.

"This document is intended for programmers writing application and system software, including operating systems, compilers, loaders, linkers, device drivers, and system utilities; it is specifically for those who want to maximize software performance. It assumes that programmers are writing compute-intensive parallel applications (streaming applications) and assumes an understanding of requisite programming practices."

One interesting detail that Guru3D pointed out is the fact that the current high-end RV770's memory read instructions do not support "burst reads." According to the documentation, "Burst memory reads are not supported by the RV770; however, the 710, 730, 740, and 790 do support it. Chips after the R770 support burst reads in memory-read instructions. This allows up to 16 consecutive locations to be read into up to 16 consecutive [General Purpose Registers]."

Surprisingly, the PDF is only 1.88MB and can be downloaded here