FDI LP3180, Руководство пользователя, Страница: 28 / 40

FDI
NXP LPC3180 Demo
User’s Manual
FDI
Rev 2 Page 28 9/7/2007
Figure 15: Probe Connections for UART Test
9.8 Exhaustive Memory Test
The memory test within the functional test code is very different from the quick memory
check implemented in the SIBL POST code. This memory test will continually write a
different pattern to each location in SDRAM and read back the pattern to make sure the
write was successful. The sequence of the test goes as follows:
1. Write a pattern to each location in SDRAM
2. Read back the pattern from each location to make sure the write was successful.
3. Complement the pattern and repeats steps 1 and 2.
4. Increment the pattern and repeats steps 1 through 4.
Due to the nature of the test, it may be exited at any time by pressing and holding the
“Clear” key on the GUI keypad until the test returns to the main menu. Also, if using
HyperTerminal, the space key may be tapped and the test will return to the main menu
following its current iteration.
9.9 ST Codec Loopback test
The current ST Codec kernel module only provides minimal initialization commands for
the chip and currently cannot be used for any particular purpose without modification.
To verify chip activity a special version of this driver was created to affectively re-
transmit all sound received on a headset microphone to the headset speaker. By default,
this driver is not loaded, but a slight modification within the /nv/startup.sh file allows it to
be enabled on boot. Simply uncomment the following lines in the file to test the
loopback driver:
#############################################
### ST Codec Loopback
#############################################
# Uncomment the following lines to remove the ST Codec driver
# and insmod the loopback one
#/bin/lsmod | grep -q vhw