Circuit-, IC descriptions and list of abbreviations
EN 134
LX7500R
9.
9.6
Service UART Interface
Logic IC 74HCT14D (item 7111) is used to make a level
conversion from microprocessor (LVTTL) to +/-5V (compatible
with most RS232 interfaces) and vice versa. The control line
MPIO19_CTL_SERVICE is used to activate service and
diagnostic SW at start up procedure. The connectivity is
provided via an external service tool.
9.7
I/O Extension Board
This board feeds the internal S/PDIF signal from the Digital
board to an optical and/or digital out connector. For European
players, also an YUV output is present on this board.