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TS-5500 User's Manual
All digital outputs on this port can source 4 mA or sink 8 mA and have logic swings between 3.3V and
ground. The digital inputs have standard TTL level thresholds and must not be driven below 0 Volts or
above 5.0 Volts. DIO lines DIO1_0 thru DIO1_7 have 4.7KΩ pull-up resistors to 5V biasing these
signals to a logic"1".
6.3 Using LCD Port as Digital I/O
The LCD Port can be used as 11 additional digital I/O lines or it can be used to interface to a standard
alphanumeric LCD display. At system reset, the port defaults to DIO mode. If using an LCD display this
port can be switched to LCD mode by writing a "1" into bit 4 at I/O location Hex 7D, or the BIOS call to
enable the LCD also sets bit 4 at I/O location Hex 7D (See Section 7 for LCD mode).
When the LCD port is in DIO mode, pins LCD_RS and LCD_WR are digital inputs, LCD_EN is a digital
LCD_6
LCD_7
14
13
LCD_4
12
11
LCD_5
LCD_2
LCD_3
10
9
LCD_0
8
7
LCD_1
LCD_WR
LCD_EN
6
5
Bias
LCD_RS
4
3
GND
2
1
5V
Figure 5 – Pinout for LCD header when
used as DIO
When bit 6 of I/O location Hex 7D is a "1", LCD_RS is connected to IRQ1 allowing this port to trigger an
interrupt.
All digital outputs on this port can source 4 mA or sink 8 mA and have logic swings between 3.3V and
ground. The digital inputs have standard TTL level thresholds and must not be driven below 0 Volts or
above 5.0 Volts. DIO lines DIO1_0 thru DIO1_7 have 4.7KΩ pull-up resistors to 5V biasing these
signals to a logic"1".
7 A/D Converter
The TS-5500 supports an optional eight-channel,
12-bit A/D converter (ADC) capable of 60,000
samples per second. Each channel is
independently software programmable for a variety
of analog input ranges: -10V to +10V, -5V to +5V,
0V to +10V, or 0V to +5V. This allows an effective
dynamic range of 14 bits. Each channel is
overvoltage tolerant from -16V to + 16V, and a fault
condition on any channel will not affect the
conversion result of the selected channel. This is
all accomplished with a 5V only power supply; no
negative supply voltage is required. The Maxim
MAX197 chip can be replaced with a MAX199
chip if a lower range of analog input levels is
required (-4V to +4V, -2V to +2V, 0V to 4V,and 0V
to 2V).
output, and LCD_0 thru LCD_7 are programmable as either
inputs or outputs.
LCD_RS and LCD_WR can be read at I/O location 73h bits 7
and 6, respectively. The state of LCD_EN is controlled by
writing to I/O location 73h bit 0.
LCD_0 thru LCD_7 can be read or written at I/O location 72h.
The direction of this byte-wide port (pins 7 – 14) is determined
by bits 2 and 3 at I/O location 7Dh. If bit 2 is a zero, then the
lower 4 bits (pins 7 – 10) are inputs. If bit 2 is logic 1, then pins 7
– 10 are outputs. Bit 3 at location 7Dh controls the upper 4 bits,
pins 11 – 14 in a like manner.
I/O Address
196h Write
196h Read
197h Read
75h Read
195h Read
Bit
Description
0-2
Analog channel select
3
Unipolar / Bipolar
4
Range select
5-7
Table 6 – A/D Control Register (196h Write)
11
Technologic Systems
Action
Initiate A/D Conversion
LSB of Conversion
MSB of Conversion
Bit 2 = 1 if A/D option installed
Bit 0 = 0 when Conversion
completed
Table 2 – A/D registers
Details
Channels 0 -7
0 = Unipolar (i.e. 0 to +5V)
1 = Bipolar (i.e. –5 to +5V)
0 = 5V range
1 = 10V range
Set to zero
10/31/03
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