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Application Note 59
Interfacing a PC Parallel Port to the
TMC22x5y RBUS Serial Interface
This circuit shows how to communicate through a IBM-
compatible parallel printer port of a generic PC to the
TMC22x5y RBUS serial interface, using the Fairchild
‘Raydemo’ revision 2A software.
To control the TMC22x5y digital video decoder with ‘Ray-
demo’ revision 2A software, simply install onto any win-
dows based PC platform, and launch raydemo.exe. The
block diagram shows the Fairchild multimedia evaluation
board which will be available 3Q96. To communicate with
the TMC22x5y double click onto the TMC22x5y decoder
symbol and select the RBUS interface. The “Raydemo’
revision 2A allows two serial addresses, SA[2:0] equal to
000 (upper decoder symbol) or 001 (lower decoder symbol).
The XLUT programming is implemented with a pick and
drag. To operate place the cursor over the XLUT point you
wish to program, click the mouse, and drag up or down to the
desired level of cross fade between the comb filter output
and the bandsplit output. Note that a level of ‘0’ will invoke
the ‘special function’ mode, and the configuration of the
XLUT can be controlled by register 0Eh bits 7 and 6.
The register maps and XLUT tables provided are not
recommended, however they do provide a good starting
point.
1
R1
10K
PC PARALLEL
PRINTER PORT 25
PIN D MALE
C1
0.1 uF
2 3 4 5 6 7 8
RBUS 4 PIN
INTERFACE
P1
1
14
2
15
3
16
4
17
5
18
6
19
7
20
8
21
9
22
10
23
11
24
12
25
13
VDD
U1A
-SCL
1
U1B
2
SCL
74LS05
-SDA
3
4
74LS05
U1C
SDA
6
74LS05
5
GND
CONNECTOR DB25
AN59
APPLICATION NOTE
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
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7/21/98 0.0m 001
Stock#AN30000059
Ó
1998 Fairchild Semiconductor Corporation
2. A critical component in any component of a life support
device or system whose failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
