PIC16C923-04I/CL Microchip Technology, PIC16C923-04I/CL Datasheet - Page 97

• Manufacturer Part Number: PIC16C923-04I/CL
• Description: 8-Bit CMOS Microcontroller with LCD Driver
• Manufacturer: Microchip Technology

13.2
The LCD timing generation provides an interrupt that
defines the LCD frame timing. This interrupt can be
used to coordinate the writing of the pixel data with the
start of a new frame. Writing pixel data at the frame
boundary allows a visually crisp transition of the image.
This interrupt can also be used to synchronize external
events to the LCD. For example, the interface to an
external segment driver, such as a Microchip AY0438,
can be synchronized for segment data update to the
LCD frame.
FIGURE 13-9: EXAMPLE WAVEFORMS IN 1/4 MUX DRIVE
1997 Microchip Technology Inc.
COM0
COM1
COM2
COM3
T
T
LCD Interrupts
FWR
FINT
= (T
= T
Frame
Boundary
(T
FRAME
FWR
FWR
/2 - (2T
/2 - (1T
/(LMUX1:LMUX0 + 1)
CY
CY
+ 40 ns))
+ 40 ns))
min.
max.
1 Frame
A new frame is defined to begin at the leading edge of
the COM0 common signal. The interrupt will be set
immediately after the LCD controller completes
accessing all pixel data required for a frame. This will
occur at a certain fixed time before the frame boundary
as shown in Figure 13-9. The LCD controller will begin
to access data for the next frame within T
interrupt.
LCD
Interrupt
occurs
T
FWR
T
FINT
Controller accesses
next frame data
Frame
Boundary
PIC16C9XX
DS30444E - page 97
FWR
V3
V2
V1
V0
V3
V2
V1
V0
V3
V2
V1
V0
V3
V2
V1
V0
after the