Here's my understanding today 6 Feb 2012: You need the ARM Architectural Reference Manual (the 'ARM ARM') which is available at. Look under 'ARM architecture / Reference Manuals' in the Contents. The applicable version is 'ARMv7-AR', which covers ARMv7-A (Cortex-A), ARMv7-R (Cortex-R), and ARMv6 which includes the ARM11 processor in RasPi's SoC.You will need to register as an ARM customer and agree to terms of use in order to download the document. I didn't have any problem when I registered maybe a year ago. JamesH said:This is also a very good book, but not easy to get (but replicated in PDF's from Arm anyway)I believe that book (ARM ARM Second Edition) is the last ARM ARM available as hard copy. I managed to get a used copy for a reasonable price before it became a 'collector's item'. It only covers through ARMv5, but that's good enough for the fixed-point instructions that most people need.
ARMv6 adds a bunch of instructions which are good for DSP applications but I doubt a C compiler would generate them. Anyway, you can set the compiler options to generate whichever ARM architecture version you want.The really nice thing about ARMv5 and ARM ARM Second Edition is that ARM instruction set formats were still easy to follow and are summarized in a few tables. ARMv7 instruction formats are a real PITA and the ARMv7-AR ARM doesn't even try to come up with a clean table for instruction formats.
IMO, 'R' hasn't stood for 'RISC' in a long time. But it's still a great processor.
User Reference Manual
ARM architectureThis page gives an overview of the ARM Architecture Reference Manuals. Read this page to help you decide which Architecture document you require. The following documents are available:.This manual describes the ARMv8-A architecture. This includes instruction set, exception model, memory model, programmers' model and the debug architecture for both the 32-bit (AArch32) and 64-bit (AArch64) execution states.PLEASE NOTE: This is a beta release of the manual.