Embedded systems: Memory Mapped I/O
Memory mapped I/O is a method of performing input/output operations between the central processing unit (CPU) and peripheral devices CPU CPU bus SPI MEMORY Module A
Memory mapped I/O uses the same address space to address both memory and I/O devices 0x00000000 Memory 0x00005000 SPI 0x00005050 UART 0x00005070 4 GB Module A . . CPU . 0x0F006000 Module N 0xFFFFFFFF CPU bus SPI MEMORY Module A
The Nios II provides memory mapped I/O access
Perform I/O operations by writing to memory location write(addr,reg,data) 0x00000000 Memory SPI UART 0 1 0x00005070 I/O PIO write(0x5070,0,0x1) . . . Module N 0xFFFFFFFF
PIO register map The Nios II CPU controls and communicates with a memory mapped module through a set of 32-bit registers Source: http://www.altera.com/literature/ug/ug_embedded_ip.pdf
Recommend
More recommend
