Tektronix RTX130B, Service Manual

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Theory of Operation
2-4
RTX130B QAM & VSB RF Signal Generator Service Manual
A180 QAM Modulator Board
Figure 2-1 shows the block diagram of the A180 QAM Modulator board.
Figure 2-1: Block diagram of the A180 QAM Modulator board
U3 (PLX PCI9030) is a PCI target device. The application software controls the
A180 board via PCI 9030. An EEPROM (U4) is connected to PCI 9030 and it
contains the PCI configuration data for the A180 board.
U37 (Xilinx Spartan-3 XC3S1500-4) is a re-configurable device that is config-
ured via the PCI bus. The application software configures the device as an ITU-T
J.83 Annex A, B, C/C-JCTEA, or ATSC 8 VSB modulator.
U13 is a 128 K by 36 bit synchronous-pipelined burst SRAM. The J.83 Annex B
modulator uses the SRAM for interleave storage, but other modulators do not
use it.
PCI Interface
Digital Modulator
SRAM