3-8 IQ80960RM/RN
Evaluation Board Manual
Hardware Reference
3.10 User LEDs
The IQ80960RM/RN platform has a ban k of eigh t use r-p rogram mable LE Ds, loca ted on t he up per edge of
the adapter board. These LEDs are controlled by a write-only register an d used as a debugging aid durin g
development. Software can contro l the state of the user LEDs by w riting to the LED Register, located at
E004 0000H. Each of the eight b its of this register correspond to one of the user LEDs. Clear ing a bit in the
LED Register by writing a “0” to it turns the corresp onding LED “on”, whil e setting a bit by writing a “1”
to it turns the correspond ing LED “off”. Resetting th e IQ80960RM/RN platfor m results in clearing the
register and turning all the LEDs “on ”. The LED Register bitmap is sho wn in Figure 3-1.
The user LEDs are numbered in descending order from left to right, with LED7 being on the left
when looking at the component side of the adapter.

3.10.1 User LEDs During Initialization

MON960 indicates the progress of its hardware initializat ion on the user LEDs. In the event that
initialization should fail for some reason, the number of lit LEDs can be used to deter mine the
cause of the failure. Ta ble 3-10 lists the tests that correspond to each lit LED.
Figure 3-1. LED Register Bitmap
76543210
User LED 7
User LED 6
User LED 5
User LED 4
User LED 3
User LED 2
User LED 1
User LED 0
Table 3-10. Start-up LEDs MON960
LEDs Tests
LED 0 SDRAM serial EEPROM checksum validated
LED 1 UART walking ones t est passed
LED 2 DRAM walking ones test pas sed
LED 3 DRAM multiword test passed
LED 4 Hardware initialization star ted
LED 5 Flash ROM initialized
LED 6 PCI-to-PCI Bridge initialized
LED 7 UART internal loopback test passed