
NOTE
Each transaction via SPI is included in
spi_sel
by a "1" level. With each
spi_sel
reset, a new transaction is started. This causes the online-status to be retransmitted in
the first two bytes.
The time sequence is shown in the following time sequence diagram and in
spi_sel
spi_clk
spi_mosi
spi_miso
POL=0
PHA=1
1
2
3
4
5
6
7
8
1
2
3
1
2
3
4
5
6
7
8
1
2
a
b
c
d e
n
n
f
g
3
h
i
Figure 37: Time control of the SPI
The time control is given in the table below:
Table 189: Time control of the SPI
Diagram
position
Description
Minimum
Maximum
Units
a
Setting
spi_sel
before
spi_clk
25
ns
b
Time for
spi_clk
high
50
ns
c
Time for
spi_clk
low
50
ns
d
Setting
spi_mosi
before
spi_clk
low
10
ns
e
Keep
spi_mosi
at
spi_clk
low
25
ns
f
Keep
spi_sel
at
spi_clk
low
260
ns
g
Delay
spi_miso
at
spi_clk
high
25
60
ns
h
Delay
spi_miso
at
spi_sel
low
25
60
ns
i
Time for
spi_sel
low
50
ns
9.2.2
Dummy read process
Due to the transmission of the online-status, Online Status read transactions need less
time for transmission via
spi_mosi
than when receiving via
spi_miso
. Therefore,
when receiving via
spi_miso
, dummy read transactions must be inserted into
spi_mosi
to avoid unwanted extra transactions.
A read access to register 3Fh has no effect and must be used for this purpose.
9.2.3
Read individual register
Using the SPI transaction "Read individual register", an individual register can be read
in the IP Core of the DSL Master.
Symbol
Meaning
R
Access bit: Read ("1")
REG ADDR
Register address (00h to 7Fh)
DUMMY ADDR
Register address for the dummy read process (3Fh)
ONLINE STATUS H
Online-status – High byte
ONLINE STATUS L
Online-status – Low byte
REG DATA
Register content
9
FPGA IP-CORE
142
T E C H N I C A L I N F O R M A T I O N | HIPERFACE DSL
®
8017595/ZTW6/2018-01-15 | SICK
Subject to change without notice