EM78P468LAQ EMC [ELAN Microelectronics Corp], EM78P468LAQ Datasheet - Page 45

• Manufacturer Part Number: EM78P468LAQ
• Description: 8-BIT Microcontroller
• Manufacturer: EMC [ELAN Microelectronics Corp]

Product Specification (V1.0) 03.15.2006
(This specification is subject to change without further notice)
4.9 LCD Driver
R9/LCDCR (LCD Control Register)
Table 3 Interrupt Vector
This LSI can drive LCD of up to 32 segments and 4 commons that can drive a total of
4*32 dots. LCD block is made up of LCD driver, display RAM, segment output pins,
common output pins, and LCD operating power supply pins. This circuit works on normal
mode, green mode and idle mode. The LCD duty; bias; the number of segment; the
number of common and frame frequency are determined by the LCD controller register.
The basic structure contains a timing control that uses a subsystem clock to generate the
proper timing for different duty and display accesses. The R9 register is a command
register for LCD driver which includes LCD enable/disable, bias (1/2 and 1/3), duty (1/2,
1/3, 1/4), and LCD frame frequency control. The register RA is an LCD contrast and LCD
RAM address control register. The register RB is an LCD RAM data buffer. LCD booster
circuit can change operation frequency to improve VLCD2 and VLCD3 drive capability.
The control register is explained as follows.
Bit 7 (BS): LCD bias select bit, 0/1=>(1/2 bias) / (1/3 bias)
Bit 6 ~ 5 (DS1 ~ DS0): LCD duty select
Bit 7
BS
Interrupt Vector
DS1
Interrupt Source
0
0
1
000CH
000FH
ENI/ DISI
0003H
0006H
0009H
0012H
0015H
0018H
Bit 6
DS1
DS0
Bit 5
DS0
X
0
1
TCC overflow interrupt.
External interrupt P5.4/INT0 pin
External interrupt P5.5/INT1 pin
Counter 1 underflow interrupt
Counter 2 underflow interrupt
High-pulse width timer underflow interrupt
Low-pulse width timer underflow interrupt
PORT 6, PORT 8 input status change wake-up
Fig. 15. Interrupt Backup Diagram
LCDEN
Bit 4
LCD Duty
1/2 duty
1/3 duty
1/4 duty
Interrupt Status
ACC
R3
Bit 3
--
Interrupt Occur
LCDTYPE
Bit 2
RETI
8-BIT Microcontroller
LCDF1
STACKACC
Bit 1
STACKR3
EM78P468L
LCDF0
Bit 0
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