uja1023 NXP Semiconductors, uja1023 Datasheet - Page 27

• Manufacturer Part Number: uja1023
• Description: Uja1023 Lin-i/o Slave
• Manufacturer: NXP Semiconductors

Philips Semiconductors
UJA1023_4
Product data sheet
7.2.3.5 Switch matrix mode
The Cyclic sense mode can be configured via the Output mode bits OM0 and OM1 in the
configuration data bytes (see
TH3 will be used instead. This feature is used for diagnosis purposes to check the
presence of a switch with an integrated parallel resistor (typical value is 2800
The switch can be detected by selecting first TH1 and then TH2.
All Px pins in Cyclic sense mode are sampled simultaneously. The Cyclic sense mode
timing is specified in
set and Sleep mode is entered when the Px pin is LOW. A wake-up will be issued when in
Sleep mode and the Px input level changes.
Figure 8
drive capability of the I/O-pins Px supports the use of a 4
components. The I/O pins from P0 to P3 provide a weak but sufficient pull-up for switch
applications and the pins from P4 to P7 are used as strong pull-down in case a switch is
pushed.
The Switch matrix mode can be enabled for the I/O-pins Px via data byte D3 of the second
configuration data block (see
The data bits SM0 and SM1 configure P0 to P3 as an input with a weak but sufficient
pull-up for switch applications and P4 to P7 as strong pull-down in order to detect an
activated switch (see
In Normal mode when a valid sync break and sync field is received, automatically a matrix
scan starts:
Fig 7. Cyclic sense mode
•
•
switch at Px
Immediately if the slave is not addressed
When addressed, after the LIN message is handled
external
capture
capture
PxOut
active
shows an application example of a 4
edge
V
Px
t
sample
Section
t
Table
on
OPEN
Rev. 04 — 5 July 2006
18).
T
11. No wake-up will occur when the local wake-up mask is
Table
Table
cy
18).
16). In case threshold TH2 is selected then threshold
CLOSE
4 switch matrix with the UJA1023. The
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
4 switch matrix without extra
UJA1023
LIN-I/O slave
mdb495
1 %).
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