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3.8.5 Capacity of backup memory (PC-Card)
Due to technological and administrational reasons the whole memory of a
PC-Card is divided into sectors. Data is always written or erased by com-
plete sectors.
Depending on the card type the following sector sizes are available:
•
SRAM cards: 256Byte
•
FLASH cards: 128kByte (:=131072Byte)
The memory is divided into the following areas:
Memory area
SRAM
FLASH
Administration information: Number of bytes (Sectors)
768 (3)
131072 (1)
Spontaneous events: Number of bytes (Sectors)
Number bytes per event
Number of events
1536 (6)
11
114 to 139
262144 (2)
11
11914 to 23831
Reset buffer:
(cumulative counters,
without rates)
Number of bytes (Sectors)
Number of bytes per reset
Number of resets
9472 (37)
1538
4 to 6
262144 (2)
1538
83 to 170
Registration period Tm1: Number of days
Programmed via DLXPARA
Registration period Tm2: Number of days
Programmed via DLXPARA
Intermediate buffer: Number of Bytes (Sectors)
0
131072 (1)
The number of stored entries per memory area varies depending on the
level of usage in individual sectors.
DLXPARA can determine the required memory capacity of a PC-Card and
this information can retrieved from the unit via SCTM protocol (see appen-
dix A: table addresses 700-80 and 700-81).
Checksums are created for each block of data to protect against corruption.
The checksum is the arithmetic sum total of a block of data and it uses one
byte of memory. The amounts carried over from the summation are dis-
carded.
Each block of data can vary in length. For buffers one block of data is
equivalent to one buffer entry. Administration information is also divided
into blocks of data.
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