Copyright © Siemens AG 2016. All rights reserved
39
ERTEC 200P-2 Manual
Technical data subject to change
Version 1.0
are required for addressing the SPI device (distance between read command 1 and iden-
tifier = number of address bytes).
Once the identifier has been read, the information on the number of words to be read is
read out (first the number of HighByte, then the number of LowByte). The following bytes
are then interpreted as data and are stored in ascending order in the D-TCM from ad-
dress 0x00...00 until the number of words to be copied is reached. The primary boot
loader then configures the D-TCM as I-TCM (
TCM926_MAP
, see 2.3.10.9.14) and the I-
TCM is shown at address 0x0000_0000. Processing then continues with a jump to ad-
dress 0x0000_0044. The length of data to be copied is limited to the maximum size of the
D-TCM.
Example:
Byte
1
2
3
4
5
6
7
8
9
10
11
12
13
...
Send-
ing
0x03
/
0xe8
0x0
0
0x0
0
0x0
0
0x0
0
0x0
0
0x0
0
0x0
0
0x0
0
0x0
0
0x0
0
0x0
0
0x0
0
...
RD
Re-
ceipt
0xff
0xff
0xff
0xff
0x5
a
0x1
0
0x0
0
0x0
0
0x0
1
0xF
F
0xF
0
0x0
0
0x0
0
...
ID
No.
of
hig
h
No.
of
low
Da-
ta 0
Da-
ta 1
Da-
ta 2
Da-
ta 3
Da-
ta 4
Da-
ta 5
...
In the example above, 0x1000 words are read from the medium. A maximum of
256 KByte (0xFFFF) can be read. A max. of 64 KByte (0x3FFF) is possible with the
current D-TCM.
Memory image in the D-TCM
TCM+0
0x00
Data 0
Word 0
TCM+1
0x01
Data 1
TCM+2
0xFF
Data 2
TCM+3
0xF0
Data 3
TCM+4
0x00
Data 4
Word 1
TCM+5
0x00
Data 5
TCM+6
0x01
Data 6
TCM+7
0x05
Data 7
TCM+8
0x00
Data 8
TCM+0x104
…..
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