MC145190EVK 데이터 시트보기 (PDF) - Motorola => Freescale
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MC145190EVK Datasheet PDF : 17 Pages
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IBM PCs and compatibles can accept up to three printer port cards. These ports are called LPT1, LPT2
and LPT3. Each printer card has jumpers or DIP switches on it to set a unique address. Two sets of
addresses are in common use. One set applies to IBM PC XT, AT, and clones. The other is for the PS 2
line. To load data into the EVK, the correct address must be selected. The program default is $278, which
is LPT1 in a clone. If $278 is not the address in use, it must be modified by entering the O menu item in
the main menu. All allowed addresses given in hexadecimal are as follows:
Label
LPT1
LPT2
LPT3
IBM PC and Clones
278
378
3BC
PS 2
3BC
378
278
Up to three EVK boards can operate independently from one printer port. All lines on the printer port are
connected to every EVK. Even with three boards operating, only three output lines (Clock, Data and
Load) from the printer card are used. If two boards are controlled together, data for the second board is
received from the Output A of the first. Output A is a configurable output on 190/191/200/201 devices,
which in this case is used to shift data through chip 1 into chip 2. Output A and Data are connected using
a printer port input line. This was done to avoid connecting extra wires. Fortunately not all port input lines
are needed for computer input. Load and Clock are common to both boards.
A three–board cascade is handled similarly to a two–board cascade. Out A on the first board is fed to
Data on the second. Out A on the second connects to Data on the third. Instructing the program on the
quantity of boards connected together allows it to modify the number of bits sent.
All boards have a DIP switch S1 which gives each a unique address. The configuration menu is used to
tell the program what type of board is connected at a board address. Switch positions for all possible
addresses are given in Figure 2.
MOTOROLA
MC145190EVK
7
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