Lexicon 960L Service Manual page 40

960L Multi-Channel Digital Effects System Service Manual
Notes:
The following tests must pass before using this test:
56301DpramTest
Z80BootTest
Z80DpramTest
Z80 Tests:
Z80 Boot Test:
The syntax for the Z80 Boot Test is: Z80BootTest CardId Z80ID [NumRepeats].
This tests the Z80's ability to execute code from the DPRAM This command resets the Z80, loads a small
piece of code into the dual port RAM (DPRAM) then checks to see if the Z80 program ran. The program
first disables the interrupts then writes the number 0xAA to address 0x000C in the DPRAM. Finally, the Z80
halts. The diagnostic program then reads the contents of address 0x000C and confirms that it is 0xAA. This
test confirms that the Z80 data bus between to the DPRAM is in tack and that at least the first 4 bits of the
address bus are good as well. As a minimum, the remaining address bits must be low (but they could well
be shorted). This test also confirms that the chip select, read and write lines to from the Z80 are making it to
the DPRAM.
Parameters:
CardID:
This number selects which reverb card to test. Legal values are 0 and 1, since only two reverb cards will be
supported. If only one card is present use the number 0.
Z80Id:
This specifies which Z80 on the card to test. Legal Values are 0 and 1.
NumRepeats:
This optional parameter specifies how many times to run the test. A value of 0 runs the test indefinitely (until
a key is pressed). Dots are shown on the display to indicate that the test is still running.
Notes:
- This test explicitly does NOT make use of the interrupt command lines (INTL, INTR).
- - It is assumed that the DPRAM Test, which accesses the DPRAM from the 56301 side, passes.
Z80 DPRAM Test:
The syntax for the Z80 DPRAM Test is: Z80DpramTest CardId Z80ID [NumRepeats].
Tests a Dual Port RAM (via a Z80). This test confirms that the Z80 can access most memory locations in
the DPRAM. The special command trigger addresses 0x03FE and 0x03FF (0x07FE and 0x07FF in Rev 1
and higher cards) are not checked by this test. This test basically confirms that programs can safely be
loaded into the DPRAM for the Z80 to run. This command loads a small piece of code into the dual port
RAM (DPRAM) which writes a data value into a memory location then halts. To perform the test, the data
and address values in the tiny Z80 program are modified repeatedly to fill the DPRAM with specific data
which the PC reads back via the 56301 (side of the DPRAM) and checks. Values of 0, 0xFF, 0xAA, and
0x55 are tested. An address test is also run that writes each address value into its associated memory
location (address 29 has the value 29 written into it, address 30 has the value 30 written into it, etc...). If this
test fails but the Z80BootTest passes, there is probably a problem with the hi address lines between the
Z80 and the DPRAM.
Parameters:
CardID:
This number selects which reverb card to test. Legal values are 0 and 1, since only two reverb cards will be
supported. If only one card is present use the number 0.
Z80Id:
6-8