![](http://datasheet.mmic.net.cn/270000/PCF2119X_datasheet_16039059/PCF2119X_6.png)
2003 Jan 30
6
Philips Semiconductors
Product specification
LCD controllers/drivers
PCF2119X
6
PAD INFORMATION
The identification of each pad and its location is given in Chapter 18.
6.1
Pad functions
Table 1
Pad function description
Note
1.
When the I
2
C-bus is used, the parallel interface pad E must be at logic 0. In the I
2
C-bus read mode DB7 to DB4 and
DB2 to DB0 should be connected to V
DD1
or left open-circuit.
a) When the parallel bus is used, pads SCL and SDA must be connected to V
SS1
or V
DD1
; they must not be left
open-circuit.
b) If the 4-bit interface is used without reading out from the PCF2119x (i.e. R/W is set permanently to logic 0), the
unused ports DB0 to DB4 can either be set to V
SS1
or V
DD1
instead of leaving them open-circuit.
SYMBOL
V
DD1
V
DD2
, V
DD3
V
SS1
V
SS2
V
LCD1
V
LCD2
DESCRIPTION
Logic supply voltage.
High voltage generator supply voltages (always put V
DD2
= V
DD3
).
This is the ground pad for all except the high voltage generator.
This is the ground pad for the high voltage generator.
This input is used for the generation of the LCD bias levels.
This is the V
LCD
output pad if V
LCD
is generated internally then pad V
LCD2
must be connected to V
LCD1
.
The pad must be left open-circuit when V
LCD
is generated externally.
This input (V
LCD
) is used for the voltage multiplier’s regulation circuitry. This pad must be connected to
V
LCD2
when using internal LCD supply and to V
LCD1
and V
LCD2
when using external LCD supply.
The data bus clock input is set HIGH to signal the start of a read or write operation; data is clocked in
or out of the chip on the negative edge of the clock; note 1.
These are three test pads. T1 and T2 must be connected to V
SS1
; T3 is left open-circuit and is not user
accessible.
LCD row driver outputs R1 to R18; these pads output the row select waveforms to the display;
R17 and R18 drive the icons. R17 has two pads R17 and R17DUP.
LCD column driver outputs C1 to C80.
I
2
C-bus serial clock input; note 1.
External power-on reset input.
PD selects the chip power-down mode; for normal operation PD = 0.
I
2
C-bus serial data input/output; note 1.
This is the read/write input. R/W selects either the read (R/W = 1) or write (R/W = 0) operation. This
pad has an internal pull-up resistor.
The RS input selects the register to be accessed for read and write. RS = 0, selects the instruction
register for write and the busy flag and address counter for read. RS = 1, selects the data register for
both read and write. This pad has an internal pull-up resistor.
The 8-bit bidirectional data bus (3-state) transfers data between the system controller and the
PCF2119x. DB7 may be used as the busy flag, signalling that internal operations are not yet
completed. In 4-bit operations the 4 higher order lines DB7 to DB4 are used; DB3 to DB0 must be left
open-circuit. Data bus line DB3 has an alternative function (SA0), when selected this is the I
2
C-bus
address pad. Each data line has its own internal pull-up resistor; note 1.
Oscillator or external clock input. When the on-chip oscillator is used this pad must be connected to
V
DD1.
V
LCDSENSE
E
T1 to T3
R1 to R18;
R17DUP
C1 to C80
SCL
POR
PD
SDA
R/W
RS
DB0 to DB7
OSC