Signal Processing; System Control - Canon PowerShot A300 Service Manual

2.2 Signal Processing

Drive Pulse
CCD
Sensor
LENS UNIT
AF Support LED
FINDER LED
Electric FLASH
MIC

2.2.1 System Control

The CPU on the main PCB ass'y controls the LENS UNIT (motor, shutter), operation switch receiver,
USB communication and flowing circuits.
• TG: Creation of the CCD drive pulse
• CDS, A/D: CCD signal processing and conversion of the digital data
• LCD Driver: Driving the LCD
• FLASH MEMORY: Firmware memory
• DSP: Picture processing
• RTC: Clock count for watch
• AF Support LED: AF auxiliary, self-timer and red-eye protection also serves as a lamp
• Electric Flash: Flash and charging circuit
MAIN PCB ASS'Y
SDRAM
HD, VD
CLK
TG
DSP
CDS, A/D
Motor
Driver
CPU
RTC
AUDIO/SP
AMP
Fig. 3 Signal System Block Diagram
2-3
CHAPTER 2. TECHNICAL DESCRIPTION
LCD
Driver
FLASH MEMORY
CF card
LCD
USB
SW
KEY
SPEAKER