sh6614 SinoWealth Micro-Electronics Corp. Ltd, sh6614 Datasheet - Page 20

• Manufacturer Part Number: sh6614
• Description: 4k 4-bit Microcontroller With Lcd Driver
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

11. LCD Driver
The LCD driver contains a controller, a voltage generator, 8 common signal pins and 30 segment driver pins. There are two
different driving modes programmable: one is 1/8 duty and 1/4 bias, the other is 1/4 duty and 1/3 bias. The driving mode is
controlled by the system register $15 and the power-on initialization status is 1/8 duty, 1/4 bias. When 1/4 duty and 1/3 bias
mode are used, COM5 - 8 is used as SEG34 - 31.
The LCD SEG1 - 30 can also be used as output port, it is selected by the bit 2 of the system register $16. When SEG1 - 30 is to
be an output port, data must be written to bit 0 of the same addresses (350H-36DH). LCD RAM could be used as data memory
if needed. When the "STOP" instruction is executed, the LCD will be turned off, but the data of LCD RAM keeps the same value
before executing the "STOP" instruction.
11.1. LCD Control Register
Frame frequency = LCDCLK/16
Frame frequency for 1/8 duty; 1/4 duty has the same frequency cycle.
The clk before (#) is selected as CPU system clk.
Frame frequency = LCDCLK/16 (32Hz)
When the LCD is set to SCAN OUT, COMx are pulled high. It is easy to implement the keyboard scan.
When the CPU is in STOP mode, the COMx and SEGx are pulled low. It can easily be woken up by a keyboard scan (Port
interrupt). When the CPU is in HALT mode, the COMx and SEGx are normal. It can easily be woken up by base timer ﹑ timer0
or port interrupt.
OSC = 32kHz (#) ,
OSC = 32kHz,
OSC = 32kHz (#) ,
OSC = 32kHz,
OSC = 32kHz (#) ,
OSC = 32kHz,
OSC = 262kHz (#) ,
OSC = 262kHz,
OSC = 262kHz (#) ,
OSC = 262kHz,
OSC = 262kHz (#) ,
OSC = 262kHz,
Add.
LCDOFF: LCD on/off switch.
DUTY: LCD duty control
LPS1, LPS0: LCD clock frequency control
*System clock = Instruction cycle time
$15
CLK Frequency
OSCX = 1.8MHz (#)
OSCX = 2MHz (#)
OSCX = 455kHz
OSCX = 1.8MHz
OSCX = 455kHz (#)
OSCX = 1.8MHz (#)
OSCX = 2MHz (#)
OSCX = 455kHz (#)
0: LCD on.
0: 1/8 duty, 1/4 bias
0,0: LCDCLK = OSC/64
0,1: LCDCLK = OSC/512
1,0: LCDCLK = System clock/512
1,1: LCDCLK = System clock/4096
OSCX = 455kHz
OSCX = 1.8MHz
OSCX = 2MHz
OSCX = 2MHz
LPS1
Bit 3
LPS0
Bit 2
256Hz
256Hz
256Hz
256Hz
256Hz
256Hz
32Hz
32Hz
32Hz
32Hz
32Hz
32Hz
0, 0
20
1: LCD off.
1: 1/4 duty, 1/3 bias
LCDOFF
Bit 1
32Hz
32Hz
32Hz
32Hz
32Hz
32Hz
4Hz
4Hz
4Hz
4Hz
4Hz
4Hz
0, 1
LPS1, LPS0
14Hz
55Hz
61Hz
14Hz
55Hz
61Hz
1, 0
1Hz
1Hz
1Hz
8Hz
8Hz
8Hz
DUTY
Bit 0
1/8Hz
1/8Hz
6.9Hz
1/8Hz
7.6Hz
6.9Hz
7.6Hz
1.7Hz
1.7Hz
1, 1
1Hz
1Hz
1Hz
SH6614/B/C