Motorola MPC823e User Manual

Clocks and Power Control
MOTOROLA MPC823e REFERENCE MANUAL 5-21
CLOCKS AND POWER
5
CONTROL
5.3.4.4 THE LCD CLOCKS. The LCD clocks—LCDCLK and LCDCLK50—are used by the
LCD controller circuitry to transfer the frame data to pixel format data. LCDCLK defaults to
VCOOUT, which is the user-defined system frequency (25-75MHz).When the PON bit in the
LCCR is set, the ratio between the system clock frequency value and the LCD clock
frequency value must be an integer value. The LCD clock frequency is the system frequency
divided by two serial dividers. LCDCLK50 is a 50% duty-cycle clock at the same frequency
as LCDCLK that is used as a clock output to the LCD panel. DFLCD and DFALCD must be
set so that the total LCD clock division factor never exceeds 64.
The LCDCLK and LCDCLK50 frequency is:
Figure 5-13. LCDCLK Divider
Figure 5-14. LCD Clock Timing Diagram
DFLCD DFALCD
LCD/VIDEO
CONTROLLER
LCD PANEL
LCDCLK
LCDCLK50
VCOOUT
LCDCLK
freq
=
LCDCLK50
freq
VCOOUT
freq
2
DFLCD
() 2 DFALCD + 1 ×()×
--------------------------------------------------------------------------------------=
LCDCLK DIVIDE BY 1
LCDCLK50 DIVIDE BY 1
LCDCLK DIVIDE BY 2
LCDCLK50 DIVIDE BY 2
LCDCLK DIVIDE BY 4
LCDCLK50 DIVIDE BY 4
GCLK2 DIVIDE BY 1
GCLK2 DIVIDE BY 2
GCLK2 DIVIDE BY 4

Motorola MPC823e Specifications

General

Brand	Motorola
Model	MPC823e
Category	Computer Hardware
Language	English