ATA5279 ATMEL Corporation, ATA5279 Datasheet - Page 23

• Manufacturer Part Number: ATA5279
• Manufacturer: ATMEL Corporation

9125A–RKE–04/08
• Select Coil Current
• Send LF Data:
Default: D
speed selected.
This command defines the current to be established for the next LF transmissions. The bits
C
In diagnosis mode, the bits C
connection line (C
AxN line).
Default: C
This command must be used to start an LF data telegram on the selected coil. The bits N
contain the amount of nibbles to be transferred into the LF data buffer of ATA5279. This
amount has to be coded as follows:
N
Hence, a maximum of 16 nibbles or 8 words and a minimum of 1 nibble can be written into
the buffer using one command.
Note also that this command uses one more word of space in the buffer, as the header word
is also stored. So for example, if the LF telegram consists of four words, the required space in
the LF data buffer is five words (four words of pure data and one word for the command
header).
It is important that the amount of nibbles passed in the header word matches the number of
words transferred afterwards to the IC, as no data consistency checking can be carried out
here. If an odd number of nibbles is to be transferred, the data word on the SPI has to be
completed with dummy data in the upper nibble, as the SPI always requires complete data
words on the bus. The FIFO buffer is also only filled with complete words.
For an example, if 7 nibbles of LF data (i.e., 14 LF data bits) are to be sent by ATA5279 via
the LF channel, the Send LF Data command consists of five words, the header word (here
06h) and four LF data words, whereas the last word contains only four bits (the four least
significant) of the LF data.
For an additional example, see
processed in ATA5279.
4..0
3..0
contain the step number in the range of 0 to 19 (00hex to 13hex).
= (n
Nibbles
G,1..0
4..0
= [00000] --> 50 mA coil current selected.
– 1)
= [001], DM = 0, BR = 0 --> Channel 1, diagnosis mode off and normal LF
0
the low/high-side switch of the AxP line, C
1
..C
Figure
0
are used to control the test switches of the activated
3-16, which illustrates how LF transmission data is
ATA5279 [Preliminary]
1
the low/high-side switch of the
3..0
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