13
6042DS–ATARM–14-Dec-06
AT91SAM7A3
7. Processor and Architecture
7.1 ARM7TDMI Processor
• RISC Processor Based on ARMv4T Von Neumann Architecture
– Runs at up to 60 MHz, providing 0.9 MIPS/MHz
• Two instruction sets
– ARM high-performance 32-bit Instruction Set
– Thumb high code density 16-bit Instruction Set
• Three-stage pipeline architecture
– Instruction Fetch (F)
– Instruction
Decode (D)
– Execute (E)
7.2 Debug and Test Features
• Integrated EmbeddedICE
™
(embedded in-circuit emulator)
– Two watchpoint units
– Test access port accessible through a JTAG protocol
– Debug communication channel
• Debug Unit
–Two-pin UART
– Debug communication channel interrupt handling
– Chip ID Register
• IEEE1149.1 JTAG Boundary-scan on all digital pins
7.3 Memory Controller
• Bus Arbiter
– Handles requests from the ARM7TDMI and the Peripheral Data Controller
• Address Decoder Provides Selection Signals for
– Three internal 1Mbyte memory areas
– One 256 Mbyte embedded peripheral area
• Abort Status Registers
– Source, Type and all parameters of the access leading to an abort are saved
– Facilitates debug by detection of bad pointers
• Misalignment Detector
– Alignment checking of all data accesses
– Abort generation in case of misalignment
• Remap Command
– Remaps the Internal SRAM in place of the embedded non-volatile memory
– Allows handling of dynamic exception vectors
• 16-area Memory Protection Unit
– Individually programmable size between 1K Bytes and 1M Bytes
