XE8000EV110 Semtech, XE8000EV110 Datasheet - Page 153

• Manufacturer Part Number: XE8000EV110
• Description: EVAL BOARD FOR XE8802AMI035LF
• Manufacturer: Semtech
• Type: MCUr

Specifications of XE8000EV110

• Contents: Fully Assembled Evaluation Board
• For Use With/related Products: XE88LC02MI035
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

19.4.2
With the 1:2 multiplex scheme, each pad_lcd_io pin drives two segments of the display. The segments of the
display are connected to the pad_lcd_io[31:0] pins. The common (or backplane) nodes are to be connected to
pad_lcd_com0 and pad_lcd_com1. This connection is shown in Figure 19-4.
Lots of different configurations for the voltage generation can be used. Figure 19-4 shows the connections and
external elements that are required if the display is to be driven from V2=1.2V and V3=2.4V independently from the
circuit supply voltage. Other possible configurations are given in section 19.5.4. Recommended values for the
external capacitors are 470nF.
To operate the driver in this configuration, the registers should be loaded with the values in Table 19-14.
The voltage generator has to be configured for the use of the internal reference (VgenRefEn=1 in RegVgenCfg0).
The generator has to run (VgenOff=0 and VgenStdb=0 in RegVgenCfg0). It has to be in 1/2 bias (VgenMode=1
in RegVgenCfg0) and the generator output impedance is set to minimum (VgenClkSel=11 in RegVgenCfg0).
© Semtech 2006
1:2 Multiplex scheme
VGEN
1.2V voltage
reference
Figure 19-4. LCD with 1:2 multiplexing and on-chip 1/2 bias voltage generation.
pad_lcd_io[31:0]
pad_lcd_com1
pad_lcd_com0
pad_vgen_v3
pad_vgen_v2
pad_vgen_v1
pad_vgen_va
pad_vgen_vb
pad_lcd_vr1
pad_lcd_vr2
RegVgenCfg0
RegLcdOn
RegLcdSe
RegLcdClkFrame
Table 19-14. Register contents for 1:2 mux example
Register
XE8802 Sensing Machine Data Acquisition MCU
C
SEGMENTS
lcd1
COM1
COM0
C
lcd2
19-9
Contents[7:0]
xx110101
xxxxx001
11111111
100xxx01
with ZoomingADC™ and LCD driver
C
aux
LCD DISPLAY
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