Panasonic EURO 4 Chassis, Техническое руководство

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14. MEMORY I.C. (EAROM)
Together with the system data for the digital IC’s,
customer data is also stored in the EAROM
IC1103 .
The stored data includes programme location data
such as channel, receiving range, standard, as well
as customer adjustment values for brightness,
volume and contrast.
The EAROM IC1103 has a memory capacity of
16384 words split into 8 bits. The carrier storage
time is equal to a minimum of ten years whereby the
read out operations are unlimited.
The read in and read out of data is controlled by the
microprocessor
IC1101 and carried out via I
2
C-
bus2. For this purpose the microprocessor IC1101
generates an 8 bit address word preceded by a start
bit. The 8 bit word is composed of a 7 bit word for the
address and 1 bit which contains the command for
reading out.
The address word is checked for compatibility with
the address contained in the IC and acknowledged
by an acknowledgement bit.
The memory location address is then transmitted by
the master I.C. (in this case the microprocessor).
This address also consists of an 8 bit word whose
reception
is again confirmed by an
acknowledgement bit. If this is the case, the 8 data
bits are then transmitted to or from the memory I.C.
and their reception is confirmed by the relevant I.C.
The transmission described above is carried out by
the SDA line and synchronised with the clock in the
SCL line.
After the transmission of the final acknowledgement
bit, the memory process is initiated on the command
’read in’. During the storage process, the memory
inputs SDA and SCL of EAROM
IC1103 are latched
in order to eliminate any external influence on the
memory during this period.
After the switch on process, the system data is read
out from the memory via the I
2
C BUS 2 by the
microprocessor.