Altera Nios Development Board Cyclone II Edition Manual do Utilizador descarregar pdf (Página 46)

2–34 Reference Manual Altera Corporation

Nios Development Board Cyclone II Edition May 2007

Board Components

Configuration & Reset Buttons

The Nios development board uses dedicated switches SW8, SW9 and

SW10 for the following fixed functions:

SW8 – CPU Reset

When SW8 is pressed, a logic-0 is driven onto the FPGA I/O pin C5

(DEV_CLRn). The result of pressing SW8 depends on how the FPGA is

configured. Refer to Figure 2–15.

The factory-programmed Nios II reference design treats SW8 as a CPU-

reset button. The Nios II reference design resets and starts executing code

from its reset address when SW8 is pressed.

Table 2–19. Configuration Status LED Indicators

LED Led Name Color Description

LED3 Loading Green This LED blinks while the configuration controller is actively

transferring data from flash memory into the FPGA.

LED4 Error Red If this LED is on, then configuration was not transferred from flash

memory into the FPGA. This can happen if, for example, the flash

memory contains either a valid user or factory configuration.

LED1 User Green This LED turns on when the user configuration is being transferred

from flash memory and stays illuminated when the user

configuration data is successfully loaded into the FPGA. If the

FPGA was successfully configured by the EPCS64, LED1 will blink

slowly.

LED2 Factory Amber This LED turns on when the factory configuration is being

transferred from flash memory and stays illuminated if the factory

configuration was successfully loaded into the FPGA.

LED6 LED6 Red This LED is an indicator of the CONFIG_DONE_signal from the

FPGA. This LED illuminates when FPGA configuration completes

successfully and CONFIG_DONE goes high.

LED7 LED7 Red This LED is an indicator of the flash_CE_n line. It illuminates when

the flash is being accessed and the CE_n line is being asserted.

1 2 ... 41 42 43 44 45 46 47 48 49 50 51 ... 63 64

Sem comentários

Altera Nios Development Board Cyclone II Edition Manual do Utilizador Página 46