Power On Self Tests - Lexicon 960L Service Manual

960L Multi-Channel Digital Effects System Service Manual
During this operation, the Boot ROM is copied to the DRAM, then the data written to the DRAM is
verified by performing a byte by byte compare with the data stored in the Boot ROM. The Main Board
MSB(1) LED is turned OFF, and the LSB(0) LED is turned ON to display the binary value of 1.
MSB(1) OFF, LSB(0) ON:
During this operation, the MMU and interrupts are enabled on the SA-1100. The Stack Pointer is
•
initialized, and the LARC2 jumps to the (C-code) program. This is where the LARC2 begins to execute
the program from the DRAM. The Serial Debug port, Keyboard 'AUX' port, and Timers (to setup the
system clock) are initialized. The LCD display is turned on displaying the 'Lexicon' splash screen.
From this point on, the software begins to continuously monitor for 'PROGRAM' + 'MACHINE' keys
being pressed. If the 'PROGRAM' + 'MACHINE' key combination is detected, a flag is set for the
LARC2 to enter Menu Mode upon completion of the Power On Diagnostic tests.
The LED's on the Main Board and Meter Board are turned off. The FPGA loads its code from the Xilinx
SPROM, and waits for the FPGA Done signal. The Main Board LSB(0) LED is turned OFF to display
the binary value of 0.
MSB(1) OFF, LSB(0) OFF:
During this operation, the GPIO's on the SA-1100 are enabled. The External Keyboard hardware is
•
reset. The HOST port is initialized, and the A/D Converters are setup (values are written to registers on
the SA-1100).

Power On Self Tests:

Pass/Fail Results:
From this point on, the Pass/Fail results for the Power On Diagnostic tests are displayed on the Meter
Board LED's. The LED column numbers are used to indicate the number of the test (1-4 & 6-8) respectively.
For example; the Pass/Fail results for Test 1 are displayed on the LED's located in column 1. The LED
colors are used to indicate the Pass/Fail status of the diagnostic tests are as follows:
Red = Failed
Yellow = Undetermined
Green = Passed
NOTE: The term 'Undetermined' means the diagnostic test did not detect the presence of a device
connected to the LARC2, and the associated circuitry in the LARC2 could not be tested. As a result, the
diagnostic test could not determine whether the associated circuitry was good or bad.
Upon normal power up (with the PS/2 Keyboard and RS-422 Wraparound Plug installed), the Meter Board
LED's will display the Power On Diagnostics test results as shown in the table below:
LED: #1 #2
Red 0 0
Yellow 0 0
Green 1 1
(0=OFF, 1=ON)
When the Interactive Diagnostics are entered by holding the 'PROGRAM' + ENTER' keys during power up,
without the PS/2 Keyboard and Wraparound Plug installed. The following Meter Board LED's will be turned
on to indicate the three errors that have been detected, as shown in the table below:
LED: #1 #2
6-28
#3 #4 #5 #6
0 0 0 0
0 0 0 0
1 1 0 1
#3 #4 #5 #6
#7 #8
0 0
0 0
1 1
#7 #8