![](http://datasheet.mmic.net.cn/Freescale-Semiconductor/MCZ33905BD3EK_datasheet_98987/MCZ33905BD3EK_37.png)
Analog Integrated Circuit Device Data
Freescale Semiconductor
37
33903/4/5
FUNCTIONAL DESCRIPTION
FUNCTIONAL PIN DESCRIPTION
Figure 22. Analog Multiplexer Block Diagram
DGB (DGB) AND DEBUG MODE
Primary Function
It is an input used to set the device in Debug mode. This is
achieved by applying a voltage between 8.0 and 10 V at the
DEBUG pin and then, powering up the device (See
StateDiagram). When the device leaves the INIT Reset mode and
enters into INIT mode, it detects the voltage at the DEBUG
pin to be between a range of 8.0 to 10 V, and activates the
Debug mode.
When Debug mode is detected, no Watchdog SPI refresh
commands are necessary. This allows an easy debug of the
hardware and software routines (i.e. SPI commands).
When the device is in Debug mode it is reported by the SPI
flag. While in Debug mode, and the voltage at DBG pin falls
below the 8.0 to 10 V range, the Debug mode is left, and the
device starts the watchdog operation, and expects the proper
watchdog refresh. The Debug mode can be left by SPI. This
is recommended to avoid staying in Debug mode when an
unwanted Debug mode selection (FMEA pin) is present. The
SPI command has a higher priority than providing 8.0 to 10 V
at the DEBUG pin.
Secondary Function
The resistor connected between the DBG pin and the GND
selects the Fail-Safe mode operation. DBG pin can also be
connected directly to GND (this prevents the usage of Debug
mode).
Flexibility is provided to select SAFE output operation via
a resistor at the DBG pin or via a SPI command. The SPI
command has higher priority than the hardware selection via
Debug resistor.
When the Debug mode is selected, the SAFE modes
cannot be configured via the resistor connected at DBG pin.
SAFE
Safe Output Pin
This pin is an output and is asserted low when a fault event
occurs. The objective is to drive electrical safe circuitry and
set the ECU in a known state, independent of the MCU and
SBC, once a failure has been detected.
The SAFE output structure is an open drain, without a pull-
up.
INTERRUPT (INT)
The INT output pin is asserted low or generates a low
pulse when an interrupt condition occurs. The INT condition
is enabled in the INT register. The selection of low level or
pulse and pulse duration are selected by SPI.
No current will flow inside the INT structure when VDD is
low, and the device is in LP VDD OFF mode. This allows the
connection of an external pull-up resistor and connection of
an INT pin from other ICs without extra consumption in
unpowered mode.
D1
VBAT
VSUP/1
S_in
I/O-1
I/O-0
Multiplexer
VDD-I_COPY
RM(*)
(*)Optional
A/D in
MCU
S_iddc
MUX-OUT
S_g3.3
Temp
VSENSE
S_g5
RSENSE 1.0 k
RMI
S_ir
S_in
VREF: 2.5 V
5V-CAN
S_I/O_att
All swicthes and resistor are configured and controlled via the SPI
RM: internal resistor connected when VREG current monitor is used
S_g3.3 and S_g5 for 5.0 V or 3.3 V VDD versions
S_iddc to select VDD regulator current copy
S_in1 for LP mode resistor bridge disconnection
S_ir to switch on/off of the internal RMI resistor
S_I/O_att for I/O-0 and I/O-1 attenuation selection
buffer
5V-CAN