Canon EOS 50 E - Page 74

Part 2: Technical Information
2) Main CPU and Major LSls and ICs
The main CPU is 1.8 times faster than the EOS 5 / A2E's and the ROM is also 1.33 larg-
er. It is the newest high-speed super microcomputer which processes large amounts of
information at high speed for horizontal and vertical Eye-Controlled Autofocus (using an
area BASIS), AF calculation at the active focusing point, and AE control with the 6-zone
metering sensor.
1. MPU (Main-CPU)
Receives various information entered with the Main Dial, Quick Control Dial, etc.
Controls the camera's overall sequence to calculate or control Eye-Controlled
Autofocus, autofocusing, AE, the motor and the LCD panel through the LCD driver.
2. LCD DR (LCD driver)
Same as the EOS A2E's. In constant operation to drive the LCD panel and the LCD
in the viewfinder. Also controls the operation switches and beeper.
3. AE IC (Exposure Metering sensor)
Same as the EOS 500/Rebel X's. Packaged in clear mold, it is a Canon-manufac-
tured LSI integrated with a highly sensitive 6-zone SPC amplifier for evaluative, par-
tial, and E-ITL evaluative autoflash metering.
4. EF IC (ITL Flash metering sensor)
Same as the EOS 500/Rebel X's. Four-zone, three-point flash metering sensor linked
to the three focusing points. Packaged in clear mold, it is a Canon-manufactured LSI
which controls the built-in flash, serves as an 1/0 communications link for external
flash units, and controls flash output.
5. BASIS (Focusing sensor)
Same as the EOS 500/Rebel X's. High-precision multi-BASIS with three focusing
points including a cross-type center focusing point. Packaged in clear mold, it is a
Canon-manufactured LSI.
6. Y- BASIS (Eye-control AF sensor)
Eye-Controlled Autofocus Area BASIS with 7,000 pixels. Suited for Eye-Controlled
Autofocus, it eliminates stray light and reads at high speed. Packaged in a clear
case, it is a Canon-manufactured LSI with various functions.
7. EEPROM
Same as the EOS A2E's. With a capacity of 2 kilobytes, it stores various adjustment
data and the frame count.
8. MD-1, MD-2 (Motor drivers)
Same as the EOS 500/Rebel X's. Motor-controlling IC. For improved control of the
coreless motor, two drivers are used in series to drive the motor.
9. REM IC (Remote control receiver IC)
Same as the EOS Elan's. Receives optical signals from the infrared remote control
transmitter dedicated to EOS cameras.
10. Y-LED IC (Eye-control AF IRED driver)
To enable horizontal and vertical Eye-Controlled autofocus, this IC selectively drives
the eight IREDs.
11. DC/DC (DC/DC control IC)
Dedicated control IC to produce a DC/DC circuit which saves space, power, and
money.
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