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The hex number following the string "DSPke" is the DSP firmware revision number. In this
example, the checksum is "25E2C24" (ignore the leading zeroes).
DSP Firmware Revision
3.11
Offset at analog outputs
Measure the DC offset at each of the 6 analog outputs (B, L, C, R, LS, RS):
3.11.1
3.11.2
3.11.3
3.11.4
3.11.5
3.11.6
All output signals are referenced to the output ground sense at J8 Pin 8.
3.12
Test signal loopback, via ADC -- L, R outputs to L,R inputs
The DSP subsystem can generate pairs of sine wave test signals of 1.378 kHz frequency
and programmable amplitude, and direct these sine waves to any two of the six outputs.
At the same time, it can also measure the signal levels present at the L/R inputs. It makes
two simple measurements: the energy present at the expected frequency (via a bandpass
filter), and the energy present everywhere else (via a notch filter). These two measure-
ments are reported back to the tester.
Using an external loopback connection, the test signals at the output can be directed back
to the input for measurement. The entire analog audio signal path (input buffers, codec
ADCs, DSPs, codec DACs) can be checked for functionality and gross distortion.
Connect the L output (J8 Pin 9) directly to the L input (J5 Pin 9).
Connect the R output (J8 Pin 7) directly to the R input (J5_1).
Issue the command:
tn 5,0,f6,0,0,2,f6,0,0
Within 500 msec, expect the response:
OK
>
Framingham, MA 01701-9168
DSP Firmware CheckSum
36
L output
J8_9
C output
J8_10
R output
J8_7
LS output
J8_12
RS output
J8-13
B output
J8_11
SIZE
FSCM
A
32108
Bose Part Number
Loewe Part Number
262234-004
350-90371.988
200mV maximum
200mV maximum
200mV maximum
200mV maximum
200mV maximum
200mV maximum
CLASS
DWG NO.
TS
264695
CheckSum
025886EB
SHEET
11 of 16
REV.
45
00
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