TLE8262E Datasheet, PDF (11/93 Pages) Infineon Technologies AG – Universal System Basis Chip HERMES Rev. 1.0

TLE8262E
State Machine
4.2
State Machine Description
The System Basis Chip (SBC) offers ten operating modes: Power On Reset, Init, Normal, Restart, Software Flash,
Sleep, Stop, Fail-Safe, Software Development, and Factory Flash Mode. The modes are controlled with one test
pin and via three mode select bits MS2..0, within the SPI. Additionally, the SBC allows five configurations,
accessed via two external pins and one SPI bit.
4.2.1 Configuration Description
Table 1 provides descriptions and conditions for entry to the different configurations of the SBC.
Table 1 SBC Configuration
Configuration Description
Test pin INT Pin WD to
LH bit
config 0
Software Development Mode
0V
n.a
n.a
config 1
After missing the WD trigger for the first time, the state of V_cc1µC Open / V_S External 0
remain unchanged, LH pin is active, SBC in Restart Mode
pull-up
config 2
After missing the WD trigger for the first time, V_cc1µC turns OFF,
LH pin is active, SBC in Fail-Safe Mode
No ext. 0
pull-up
config 3
After missing the WD trigger for the second time, the state of
V_cc1µC remain unchanged, LH pin is active, SBC in Restart
Mode
External 1
pull-up
config 4
After missing the WD trigger for the second time, V_cc1µC turns
OFF, LH pin is active, SBC in Fail-Safe Mode
No ext. 1
pull-up
In SBC SW Development Mode, Config 1 to 4 are accessible.
4.2.2 SBC Power ON Reset (POR)
At V_S > V_UVON, the SBC starts to operate, by reading the test pin and then by turning ON V_cc1µC. When V_cc1µC
reaches the reset threshold V_RT1, the reset output remains activated for t_RD1 and the SBC enters then the Init Mode.
In the event that V_s decreases below V_UVOFF, the device is completely disabled. For more details on the disable
behavior of the SBC blocks, please refer to the chapter specific to each block.
4.2.3 SBC Init Mode
At entering the SBC Init Mode, the SBC starts to read the Test pin. The SBC starts-up in SBC Init Mode, and, after
powering-up, waits for the microcontroller to finish its startup and initialization sequences. V_cc2/3 are OFF and the
Watchdog is configurable but not active. CAN and LIN modules are inactive and Limp Home output is inactive.
From this transition mode, the SBC can be switched via SPI command to the desired operating mode, SBC Normal
or Software Flash Mode. If the SBC does not receive any SPI command, or receive wrong SPI command (i.e. not
send the device to SBC Normal or SBC SW Flash Mode) within a 256 ms time frame after the reset relaxation, it
will enter into SBC Restart Mode and activate the Limp Home output.
Note: In Init Mode it is recommended to send one SPI command that sets the device to Normal Mode, triggers the
watchdog the first time and sets the required watchdog settings.
Data Sheet
11
Rev. 1.0, 2009-03-31