V
130447-1 Rev. A IQ-USM 810 Service Manual
©2000 Crown International, Inc.
Table of Contents

1 Introduction ............................................................................ 1-1

1.1 Introduction ................................................................................1-1
1.2 The IQ-USM 810 ........................................................................1-1
1.3 Warranty..................................................................................... 1-1

2 Specifications .........................................................................2-1

3 Circuit Theory ........................................................................3-1

3.1 Overview ....................................................................................3-1
3.2 Power Supply .............................................................................3-1
3.3 Input ...........................................................................................3-1
3.3.1 Input Analog Processing................................................... 3-1
3.3.2 Clock Signals ....................................................................3-2
3.3.3 A/D Conversion .................................................................3-2
3.3.4 DC Voltages ......................................................................3-4
3.4 Output ........................................................................................3-4
3.4.1 Clock Buffers..................................................................... 3-4
3.4.2 DAC Conversion................................................................ 3-4
3.4.3 Output Analog Processing................................................ 3-4
3.5 SHARC Processing ....................................................................3-5
3.5.1 +3.3V Power Supply.......................................................... 3-5
3.5.2 Clocks ...............................................................................3-5
3.5.3 Reset .................................................................................3-5
3.5.4 System Control Interface................................................... 3-5
3.5.5 PLDs.................................................................................. 3-6
3.5.6 Bus Arbitration................................................................... 3-6
3.5.7 Bus Utilization.................................................................... 3-6
3.5.8 DSP Processing ................................................................3-6
3.5.9 Audio Routing.................................................................... 3-8
3.6 System Controller....................................................................... 3-8
3.6.1 Control Processing............................................................ 3-9
3.6.2 RS232.............................................................................. 3-10
3.6.3 Crown Bus Loop.............................................................. 3-10
3.6.4 Real Time Clock ..............................................................3-10
3.6.5 Front Panel ......................................................................3-10
3.6.6 Control Port .....................................................................3-10
3.7 Front Display ............................................................................3-10

4 Maintenance........................................................................... 4-1

4.1 General Information....................................................................4-1
4.2 Definitions................................................................................... 4-1
4.3 Required Test Equipment.......................................................... 4-1
4.4 Message String Syntax.............................................................. 4-2