Rainbow Electronics AT91CAP9S250A - Manual (Page 21)

21
6264A–CAP–21-May-07
AT91CAP9S500A/AT91CAP9S250A
• Embeds 4 unidirectional channels with programmable priority
• Address Generation
– Source / destination address programming
– Address increment, decrement or no change
– DMA chaining support for multiple non-contiguous data blocks through use of linked
lists
– Scatter support for placing fields into a system memory area from a contiguous
transfer. Writing a stream of data into non-contiguous fields in system memory
– Gather support for extracting fields from a system memory area into a contiguous
transfer
– User enabled auto-reloading of source, destination and control registers from initially
programmed values at the end of a block transfer
– Auto-loading of source, destination and control registers from system memory at end
of block transfer in block chaining mode
– Unaligned system address to data transfer width supported in hardware
• Channel Buffering
– 8-word FIFO
– Automatic packing/unpacking of data to fit FIFO width
• Channel Control
– Programmable multiple transaction size for each channel
– Support for cleanly disabling a channel without data loss
– Suspend DMA operation
– Programmable DMA lock transfer support
• Transfer Initiation
– Support four External DMA Requests and four Internal DMA request from the MP
Block
– Support for Software handshaking interface. Memory mapped registers can be used
to control the flow of a DMA transfer in place of a hardware handshaking interface
• Interrupt
– Programmable Interrupt generation on DMA Transfer completion Block Transfer
completion, Single/Multiple transaction completion or Error condition
7.8 Debug and Test Features
• ARM926 Real-time In-circuit Emulator
– Two real-time Watchpoint Units
– Two Independent Registers: Debug Control Register and Debug Status Register
– Test Access Port Accessible through JTAG Protocol
– Debug Communications Channel
• Debug Unit
– Two-pin UART
– Debug Communication Channel Interrupt Handling
– Chip ID Register
• IEEE1149.1 JTAG Boundary-scan on All Digital Pins