S912XHY128F0VLM Datasheet, PDF (557/802 Pages) Freescale Semiconductor, Inc – S12 Microcontrollers

Liquid Crystal Display (LCD40F4BV2) Block Description
Table 17-7. LCD RAM Field Descriptions
Field
Description
39:0
3:0
FP[39:0]
BP[3:0]
LCD Segment ON — The FP[39:0]BP[3:0] bit displays (turns on) the LCD segment connected between FP[39:0]
and BP[3:0].
0 LCD segment OFF
1 LCD segment ON
17.4 Functional Description
This section provides a complete functional description of the LCD40F4BV2 block, detailing the
operation of the design from the end user perspective in a number of subsections.
17.4.1 LCD Driver Description
17.4.1.1 Frontplane, Backplane, and LCD System During Reset
During a reset the following conditions exist:
• The LCD40F4BV2 system is configured in the default mode, 1/4 duty and 1/3 bias, that means all
backplanes are used.
• All frontplane enable bits, FP[39:0]EN are cleared and the ON/OFF control for the display, the
LCDEN bit is cleared, thereby forcing all frontplane and backplane driver outputs to the high
impedance state. The MCU pin state during reset is defined by the port integration module (PIM).
17.4.1.2 LCD Clock and Frame Frequency
The frequency of the source clock (IRCCLK) and divider determine the LCD clock frequency. The divider
is set by the LCD clock prescaler bits, LCLK[2:0], in the LCD control register 0 (LCDCR0). Table 17-8
shows the LCD clock and frame frequency for some multiplexed mode at IRCCLK = 16 MHz, 8 MHz, 4
MHz, 2 MHz, 1 MHz, and 0.5 MHz.
Table 17-8. LCD Clock and Frame Frequency
Source clock
Frequency in
MHz
IRCCLK = 0.5
IRCCLK = 1.0
IRCCLK = 2.0
IRCCLK = 4.0
IRCCLK = 8.0
LCD Clock Prescaler
LCLK2 LCLK1 LCLK0
Divider
LCD Clock
Frequency [Hz]
Frame Frequency [Hz]
1/1 Duty 1/2 Duty 1/3 Duty 1/4 Duty
0
0
0
1024
488
0
0
1
2048
244
0
0
1
2048
488
0
1
0
4096
244
0
1
0
4096
488
0
1
1
8192
244
0
1
1
8192
488
1
0
0
16384
244
1
0
0
16384
488
1
0
1
32768
244
488
244
163
122
244
122
81
61
488
244
163
122
244
122
81
61
488
244
163
122
244
122
81
61
488
244
163
122
244
122
81
61
488
244
163
122
244
122
81
61
MC9S12XHY-Family Reference Manual, Rev. 1.01
Freescale Semiconductor
557