PCA85233 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet Rev. 4 — 6 May 2015 13 of 54
NXP Semiconductors
PCA85233
Automotive 80 × 4 LCD driver for low multiplex rates
mode, the contents of rows 2 and 3 may be selected instead of rows 0 and 1. This gives
the provision for preparing display information in an alternative bank and to be able to
switch to it once it is assembled.
7.3.6 Input bank selector
The input bank selector loads display data into the display RAM in accordance with the
selected LCD drive configuration. Display data can be loaded in row 2 in static drive mode
or in rows 2 and 3 in 1:2 multiplex drive mode by using the bank-select command (see
Table 9
). The input bank selector functions independently to the output bank selector.
7.4 Initialization
At power-on the status of the I
2
C-bus and the registers of the PCA85233 is undefined.
Therefore the PCA85233 should be initialized as quickly as possible after power-on to
ensure a proper bus communication and to avoid display artifacts. The following
instructions should be accomplished for initialization:
• I
2
C-bus (see Section 8) initialization
– generating a START condition
– sending 0h and ignoring the acknowledge
– generating a STOP condition
• Mode-set command (see Table 6), setting
– bit E = 0
– bit B to the required LCD bias configuration
– bits M[1:0] to the required LCD drive mode
• Load-data-pointer command (see Table 7), setting
– bits P[6:0] to 0h (or any other required address)
• Device-select command (see Table 8), setting
– bits A[1:0] to the required hardware subaddress (for example, 0h)
• Bank-select command (see Table 9), setting
– bit I to 0
– bit O to 0
• Blink-select command (see Table 10), setting
– bit AB to 0 or 1
– bits BF[1:0] to 00 (or to a desired blinking mode)
• writing meaningful information (for example, a logo) into the display RAM
After the initialization, the display can be switched on by setting bit E = 1 with the
mode-set command.
7.5 Possible display configurations
The PCA85233 is a versatile peripheral device designed to interface between any
microcontroller to a wide variety of LCD segment or dot matrix displays (see Figure 6
). It
can directly drive any static or multiplexed LCD containing up to four backplanes and up to
80 segments.
