NXP Semiconductors MC9S08LG16, Reference Manual

Page: 188 / 373

Chapter 8 LCD Module (S08LCDLPV1)
MC9S08LG32 MCU Series, Rev. 5
188 Freescale Semiconductor
9.4.4.2.1 LCD External Power Supply, VSUPPLY[1:0] = 11
When VSUPPLY[1:0] = 11, powersw1, and powersw2 are deasserted. V
DD
is not available to power the
LCD module internally, so the LCD module requires an external power source for V
LL1,
V
LL2,
and V
LL3
when the charge pump is disabled.
If the charge pump is enabled, external power must be applied to V
LL3
. With this configuration, the charge
pump will generate the other LCD bias voltages V
LL1
and V
LL2.
9.4.4.2.2 LCD Internal Power Supply, VSUPPLY[1:0] = 00 or 01
V
DD
is used as the LCD module power supply when VSUPPLY[1:0] = 00 or 11 ( Table 9-20
).
Table 9-20
provides recommendations regarding configuration of the VSUPPLY[1:0] bit field when using both 3 V
and 5 V LCD panels.
9.4.5 Resets
During a reset, the LCD module system is configured in the default mode. The default mode includes the
following settings:
V
LL3
is driven externally for 3 V LCD Glass
operation.
Resistor Bias Network enabled.
For 3 V glass operation V
LL3
must equal 3 V.
Charge pump is disabled.
Resistor Bias network is used to create V
LL1
and V
LL2
11 0
V
LL3
is driven externally for 5 V LCD Glass
operation. Resistor Bias network enabled.
V
LL3
must equal V
DD
For 5 V glass operation V
LL3
must equal 5 V.
Charge pump is disabled.
Resistor Bias network is used to create V
LL1
and V
LL2
.
11 0
Table 9-20. V
DD
Switch Option
VSUPPLY[1:0] V
DD
Switch Option
Recommend Use for 3-V
LCD Panels
Recommend Use for 5-V
LCD Panels
00 V
LL2
is generated from V
DD
• V
LL1
= 1 V
• V
DD
= V
LL2
= 2 V
• V
LL3
= 3 V
• V
LL1
= 1.67 V
• V
DD
= V
LL2
= 3.3 V
• V
LL3
= 5 V
01 V
LL3
is generated from V
DD
• V
LL1
= 1 V
• V
LL2
= 2 V
• V
DD
= V
LL3
= 3 V
• V
LL1
= 1.67 V
• V
LL2
= 3.33 V
• V
DD
= V
LL3
= 5 V
Table 9-19. LCD Power Supply Options (continued)
LCD Operational State LCD Power Supply Configuration
VSUPPL
Y[1:0]
CPSEL