PCF2119X_10 Datasheet, PDF (42/83 Pages) NXP Semiconductors – LCD controllers/drivers Single-chip LCD controller and driver

NXP Semiconductors
PCF2119x
LCD controllers/drivers
11. Basic architecture
11.1 Parallel interface
The PCF2119x can send data in either two 4-bit operations or one 8-bit operation and can
thus interface to 4-bit or 8-bit microcontrollers.
In 8-bit mode data is transferred as 8-bit bytes using the 8 ports DB7 to DB0. Three further
control lines E, RS and R/W are required.
In 4-bit mode data is transferred in two cycles of 4 bits each using ports DB7 to DB4 for
the transaction. The higher order bits (corresponding to range of bit 7 to bit 4 in 8-bit
mode) are sent in the first cycle and the lower order bits (bit 3 to bit 0 in 8-bit mode) in the
second cycle. Data transfer is complete after two 4-bit data transfers. It should be noted
that two cycles are also required for the busy flag check. 4-bit operation is selected by
instruction (see Figure 24 to Figure 26 for examples of bus protocol).
In 4-bit mode, ports DB3 to DB0 must be left open-circuit. They are pulled up to V_DD
internally.
RS
R/W
E
DB7
IR7
IR3
DB6
IR6
IR2
DB5
IR5
IR1
DB4
IR4
IR0
instruction
write
Fig 24. 4-bit transfer example
BF
AC3
AC6
AC2
AC5
AC1
AC4
AC0
busy flag and
address counter read
DR7
DR3
DR6
DR2
DR5
DR1
DR4
DR0
data register
read
mga804
PCF2119X
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 7 — 15 November 2010
© NXP B.V. 2010. All rights reserved.
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