em6521 EM Microelectronic, em6521 Datasheet - Page 49

• Manufacturer Part Number: em6521
• Description: Mfp Version Of Em6621 Ultra Low Power Microcontroller With 4x20 Lcd Driver
• Manufacturer: EM Microelectronic

14.3 Free Segment Allocation
Each Segment (SEG[20:1]) terminal outputs the time multiplexed information from its 4 Segment data latches.
Information stored in latch 1 is output during phase1, latch 2 during phase 2, latch 3 during phase 3 and latch 4
during phase 4. In the case of 3 to 1 multiplexing the phase 4 and the latch 4 are not used. This phase
information on the segment outputs together with the common outputs (COM[4:1]) - also called back-planes -
defines if a given LCD segment is light or not. COM[1] is on during phase 1 and off during phase 2,3,4 ,
COM[2] is on during phase 2 and off during phase 1,3,4 , etc.
For each segment data latch the address location within the LCD address spacing ( LCD_3 + Index(8), LCD_2
+ Index(16), LCD_1 + Index(16) --> LCDAdr[39:0] ) can be user defined.
For each segment data latch the data bus connection (DB[3:0]) can be user defined.
Table 14.3.1 Default LCD Configuration used on EM6521
14.4 LCD Registers
Table 14.4.1 Register RegLcdCntl1
Table 14.4.2 Multiplier Clock Frequency Select
Table 14.4.3 Register LcdCntl2
Copyright © 2005, EM Microelectronic-Marin SA
Segment outputs
StrobeOutSel1,0 is reset by initial power on only.
Bit
Bit
3
2
1
0
CkTripSel0
3
2
1
0
SEG[18]
SEG[19]
SEG[20]
SEG[1]
SEG[2]
SEG[3]
LCDExtSupply is reset to ‘0’ by POR only.
...
0
1
0
1
R
LCDExtSupply
StrobeOutSel1
StrobeOutSel0
CkTripSel1
CkTripSel0
LCDBlank
LCD4Mux
LCDOff
Name
Name
DB[0], LCDAdr[18]
DB[0], LCDAdr[19]
DB[0], LCDAdr[20]
DB[0], LCDAdr[0]
DB[0], LCDAdr[1]
DB[0], LCDAdr[2]
= phase1
COM[1]
CkTripSel1
...
0
0
1
1
POR to ‘0’
POR to ‘0’
POR to ‘0’
Reset
Reset
1
1
1
0
0
DB[1], LCDAdr[18]
DB[1], LCDAdr[19]
DB[1], LCDAdr[20]
DB[1], LCDAdr[0]
DB[1], LCDAdr[1]
DB[1], LCDAdr[2]
Multiplier Clock
= phase2
R/W
R/W
R/W
R/W
R/W
COM[2]
R/W
R/W
R/W
R/W
R/W
...
Ck[10]
Ck[9]
Ck[8]
Ck[7]
49
External supply for VL1, VL2 and VL3
DB[2], LCDAdr[18]
DB[2], LCDAdr[19]
DB[2], LCDAdr[20]
DB[2], LCDAdr[0]
DB[2], LCDAdr[1]
DB[2], LCDAdr[2]
LCD multiplier clock select
LCD multiplier clock select
LCD Segment outputs off
= phase3
LCD off (multiplier off)
COM[3]
Strobe output select
Strobe output select
4 : 1 multiplexed
...
on 32 KHz operation
Description
Description
512 Hz
256 Hz
128 Hz
64 Hz
www.emmicroelectronic.com
DB[3], LCDAdr[18]
DB[3], LCDAdr[19]
DB[3], LCDAdr[20]
EM6521
DB[3], LCDAdr[0]
DB[3], LCDAdr[1]
DB[3], LCDAdr[2]
= phase4
COM[4]
...