pcf8566 NXP Semiconductors, pcf8566 Datasheet - Page 22

• Manufacturer Part Number: pcf8566
• Description: Universal Lcd Driver For Low Multiplex Rates
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Table 7 LCD bias configuration
Table 8 Display status
Table 9 Power dissipation mode
Table 10 Load data pointer
Table 11 Device select
Table 12 Input bank selection
Table 13 Output bank selection
Table 14 Blinking frequency
1998 May 04
1
1
Disabled (blank)
Enabled
Normal mode
Power-saving mode
RAM bit 0
RAM bit 2
RAM bit 0
RAM bit 2
Off
2 Hz
1 Hz
0.5 Hz
FREQUENCY
3
2
Universal LCD driver for low multiplex
rates
bias
bias
BITS
DISPLAY STATUS
STATIC
STATIC
BLINK
LCD BIAS
MODE
BITS
5-bit binary value of 0 to 23
3-bit binary value of 0 to 7
P4
RAM bits 0, 1
RAM bits 2, 3
RAM bits 0, 1
RAM bits 2, 3
1 : 2 MUX
1 : 2 MUX
BIT BF1
P3
0
0
1
1
A0
P2
BIT LP
BIT B
BIT E
A1
0
1
0
1
0
1
P1
BIT BF0
BIT 1
BIT 0
0
1
0
1
0
1
0
1
A2
P0
22
Table 15 Blink mode selection
7.9
The display controller executes the commands identified
by the command decoder. It contains the status registers
of the PCF8566 and coordinates their effects.
The controller is also responsible for loading display data
into the display RAM as required by the filling order.
7.10
In large display configurations, up to 16 PCF8566s can be
distinguished on the same I
hardware subaddress (A0, A1 and A2) and the
programmable I
possible to cascade up to 16 PCF8566s. When cascaded,
several PCF8566s are synchronized so that they can
share the backplane signals from one of the devices in the
cascade. Such an arrangement is cost-effective in large
LCD applications since the outputs of only one device
need to be through-plated to the backplane electrodes of
the display. The other PCF8566s of the cascade
contribute additional segment outputs but their backplane
outputs are left open-circuit (Fig.17).
The SYNC line is provided to maintain the correct
synchronization between all cascaded PCF8566s.
This synchronization is guaranteed after the power-on
reset. The only time that SYNC is likely to be needed is if
synchronization is accidentally lost (e.g. by noise in
adverse electrical environments; or by the definition of a
multiplex mode when PCF8566s with differing SA0 levels
are cascaded). SYNC is organized as an input/output pin;
the output section being realized as an open-drain driver
with an internal pull-up resistor. A PCF8566 asserts the
SYNC line at the onset of its last active backplane signal
and monitors the SYNC line at all other times.
Should synchronization in the cascade be lost, it will be
restored by the first PCF8566 to assert SYNC. The timing
relationships between the backplane waveforms and the
SYNC signal for the various drive modes of the PCF8576
are shown in Fig.18. The waveforms are identical with the
parent device PCF8576. Cascade ability between
PCF8566s and PCF8576s is possible, giving cost effective
LCD applications.
Normal blinking
Alternation blinking
Display controller
Cascaded operation
BLINK MODE
2
C-bus slave address (SA0). It is also
2
C-bus by using the 3-bit
Product specification
BIT A
PCF8566
0
1