Metz mecablitz 40 MZ-2 Servicehandbuch Seite 31

Technik und Service
Technology and Service
EEPROM:
The EEPROM IC302 stores data which must be retained even if the batteries are removed, namely
the 9 user settings, the current settings, various alignment values and the table for partial light
output values.
IC302 is synchronized with the clock of IC301 (at pin 30) via pin 2. Whenever IC301 accesses IC302,
the chip select signal at pin 28 switches to high and IC302 switches to wait mode. The exchange of
data for program execution is carried out via the bidirectional data line at pin 31 of IC301. On
IC302, the data input at pin 3 and the data output at pin 4 are used for the exchange.
Serial interfaces:
ASIC bus:
The ASIC bus is a unidirectional serial interface between IC301 and the ASIC, IC504, via which IC301
passes various control parameters to the ASIC, namely:
- operating mode
- parameters for automatic light output control
- parameters for control of the partial light output levels
- parameters for control of the Canon resistors
- frequency and volume parameters for the buzzer
- control of the exposure check function, of the main and auxiliary converters
and of the supply voltage for the SCA 3000 adapter.
The ASIC bus consists of a clock line (IC301 pin 30 to ASIC pin 5) and a data line (IC301 pin 32 to
ASIC pin 4).
SCA bus:
This serial interface from IC301 to the SCA connector is bidirectional and the data traffic can be
initiated either by IC301, by the SCA adapter or by the test set MB 3000 (if this is connected). The
following data are transferred via this bus:
Flashgun data (from mecablitz to SCA):
light output, guide number, reflector position, operating mode, stroboscope frequency, number of
flashes, flash readiness, exposure check indicator, reflector swivelled, etc.
Camera data (from SCA to mecablitz):
ISO value, aperture, focal length, exposure correction values, camera operating modes, remote
address, etc.
Test/alignment data (from/to Test Set MB 3000):
EEPROM data, port status data, A/D converter measured values
The following inputs and outputs on IC301 are used for the exchange of these data:
mecablitz 40 MZ-2
Seite: 31
Page: 31
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