ST6246 STMICROELECTRONICS [STMicroelectronics], ST6246 Datasheet - Page 7

• Manufacturer Part Number: ST6246
• Description: 8-BIT OTP/EPROM MCU WITH LCD DRIVER, EEPROM AND A/D CONVERTER
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

1.2 PIN DESCRIPTIONS
V
these two pins. V
V
OSCin and OSCout. These pins are internally
connected to the on-chip oscillator circuit. A quartz
crystal, a ceramic resonator or an external clock
signal can be connected between these two pins.
The OSCin pin is the input pin, the OSCout pin is
the output pin.
RESET . The active-low RESET pin is used to re-
start the microcontroller.
TEST/V
mal operation (an internal pull-down resistor se-
lects normal operating mode if TEST pin is not
connected). If TEST pin is connected to a +12.5V
level during the reset phase, the EPROM/OTP
programming Mode is entered.
NMI. The NMI pin provides the capability for asyn-
chronous interruption, by applying an external non
maskable interrupt to the MCU. The NMI input is
falling edge sensitive with Schmitt trigger charac-
teristics. The user can select as option the availa-
bility of an on-chip pull-up at this pin.
PA4-PA7. These 4 lines are organised as one I/O
port (A). Each line may be configured under soft-
ware control as inputs with or without internal pull-
up resistors, input with interrupt generation and
pull-up resistor, open-drain or push-pull outputs, or
as analog inputs for the A/D converter.
PB0...PB7. These 8 lines are organised as one I/O
port (B). Each line may be configured under soft-
ware control as inputs with or without internal pull-
up resistors, input with interrupt generation and
pull-up resistor, open-drain or push-pull outputs,
analog inputs for the A/D converter. PB0..PB3 can
be used as analog inputs for the A/D converter ,
while PB7/Sout, PB6/Sin and PB5/Scl can be used
respectively as data out, data in and Clock pins for
DD
SS
is the ground connection.
and V
PP
. The TEST must be held at V
SS
. Power is supplied to the MCU via
DD
is the power connection and
SS
for nor-
the on-chip SPI. In addition, PB4..PB7 can sink
20mA for direct LED or TRIAC drive.
PC0-PC7. These 8 lines are organised as one I/O
port (C). Each line may be configured under soft-
ware control as input with or without internal pull-
up resistor, input with interrupt generation and
pull-up resistor, open-drain or push-pull output, or
as LCD segment output S33..S40.
COM1-COM4 . These four pins are the LCD pe-
ripheral common outputs. They are the outputs of
the on-chip backplane voltage generator which is
used for multiplexing the 45 LCD lines allowing up
to 180 segments to be driven.
S9..S16, S25..S43. These pins are the 27 LCD pe-
ripheral segment outputs. S33..S40 are alternate
functions of the Port C I/O pins. (Combiports fea-
ture)
VLCD. Display voltage supply. It determines the
high voltage level on COM1-COM4 and S4-S48
pins.
VLCD1/3, VLCD2/3 . Display supply voltage inputs
for determining the display voltage levels on
COM1-COM4 and S4-S48 pins during multiplex
operation.
PSS . This is the Power Supply Supervisor sensing
pin. When the voltage applied to this pin is falling
below a software programmed value the highest
priority (NMI) interrupt can be generated. This pin
has to be connected to the voltage to be super-
vised.
OSC32in and OSC32out. These pins are inter-
nally connected with the on-chip 32kHz oscillator
circuit. A 32.768kHz quartz crystal can be con-
nected between these two pins if it is necessary to
provide the LCD stand-by clock and real time inter-
rupt. OSC32in is the input pin, OSC32out is the
output pin.
ST62T46B/E46B
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