UJA1061 Datasheet, PDF (57/81 Pages) NXP Semiconductors – Low speed CAN/LIN system basis chip

Philips Semiconductors
Low speed CAN/LIN system basis chip
Objective specification
UJA1061
6.16.2 FORCED NORMAL MODE
For system evaluation purposes the UJA1061 contains the
Forced Normal mode. During this test the UJA1061
operates in Normal mode with disabled watchdog. All the
voltage regulators are switched ON. The CAN-transceiver
operates in Active and Automatic Fault-tolerant mode. The
LIN-transceiver operates in Active mode and this mode
can be activated only with a stable HIGH-level (12 V) at pin
TEST during the first battery connection. Leaving this
mode and entering the Normal operating mode will be
executed after releasing the TEST pin (level at 0 V).
Entering the Forced Normal mode again is possible only
by disconnection of the battery supply (BAT42) thus
forcing a new power-on period for the UJA1061.
The behaviour of the UJA1061 in Forced Normal mode is
as follows:
• SPI access (writing and reading) is blocked
• Watchdog is disabled
• Interrupt Monitoring is disabled
• Reset Monitoring is disabled
• UJA1061 is held in Normal mode; any transition to
Fail-safe mode is disabled and the UJA1061 remains in
the mode in which the problem occurred; the only
exception that results in entry into Fail-safe mode is a V1
undervoltage longer than 256 ms as self-protection of
the SBC
• V1 is started with the defined Reset
(20 ms LOW-to-HIGH)
• V2 is ON; undervoltage protection is still active, which
results in V2 switching OFF; V2 can only be switched on
again by disconnecting the TEST and BAT pins and then
reconnecting first the TEST pin and later the BAT42/14
pin
• CAN and LIN are in active mode and cannot switch to an
Off-line mode
• V3 is ON; undervoltage protection is still active, which
results in V3 switching OFF; V3 can only be switched on
again by disconnecting the TEST and BAT pins and then
reconnecting first the TEST pin and later the BAT42/14
pin
• INH is ON
• SYSINH is ON
• In the case of a V1 undervoltage, a reset will be
performed until V1 is restored (normal behaviour); the
UJA1061 stays in Forced Normal mode; in case of a
continuous overload at V1 (> 256 ms) Fail-safe mode
will be entered; V1 can be switched on again only by
disconnecting the TEST and BAT pins and then
reconnecting first the TEST pin and later the BAT42/14
pin
• Pulling pin RSTN LOW externally will not result in
leaving the Forced Normal mode, the UJA1061 will
ignore external resets; this is because the FLASH
programmer uses pin RSTN for other purposes (i.e. the
FLASH programmer uses the RSTN line for serial
communication entering/preparing the FLASH ROM
routines with special sequences)
• No Reset Lengthening
• Directly after pin RSTN is released, pin EN will go HIGH;
a LOW value on pin RSTN (but not an external LOW
value) will result in a LOW value on the pin EN; pin EN
stays active all the time during Forced Normal mode.
2004 Mar 22
57