User Manual
BCM91125E
04/27/05
B ro a d c o m C o r p o r a t i o n
Document
91125E-UM100-R
Switches and Pushbuttons
Page 9
S
WITCHES
AND
P
USHBUTTONS
Figure 6 shows the locations of each of the switches and pushbuttons. Table 4 describes the function of each
switch or pushbutton.
Figure 6: Switch Callouts
Table 4: Switch Descriptions
Board ID Function
Default
SW1
16-position rotary switch to set the power-on state of IO_AD[31-28],
which are captured in system_cfg[31:28], also called the config[5:2].
These bits are used by the CFE to select the firmware configuration
according to Table 7, and could be used for other purposes according to
customer software requirements.
0x2
SW2
Cold Reset is asserted when the button is pressed.
N/A
SW3
NMI (GPIO 8) is asserted when the button is pressed.
N/A
SW4
2-position DIP switch, for hardware configuration. These bits have
dedicated purposes that do not change under firmware control.
Bit[2] = Big Endian enable (ON = big endian, OFF = little endian).
ON
Bit[1] = Boot from ROM emulator (ON = ROM emulator, OFF = Flash).
See also Table 5.
OFF
