MC33910G5AC/MC3433910G5AC
FUNCTIONAL DEVICE OPERATIONS
OPERATIONAL MODES
FUNCTIONAL DEVICE OPERATIONS
OPERATIONAL MODES
The VDD regulator is ON and delivers its full current
capability.
INTRODUCTION
The 33910 offers three main operating modes: Normal
(Run), Stop, and Sleep (Low Power). In Normal mode, the
device is active and is operating under normal application
conditions. The Stop and Sleep modes are low power modes
with wake-up capabilities.
If an external resistor is connected between the WDCONF
pin and the Ground, the window watchdog function will be
enabled.
The wake-up input (L1) can be read as digital input or have
its voltage routed through the analog-multiplexer.
In Stop mode, the voltage regulator still supplies the MCU
with VDD (limited current capability), while in Sleep mode the
voltage regulator is turned off (VDD = 0 V).
The LIN interface has slew rate and timing compatible with
the LIN protocol specification 2.0, 2.1 and SAEJ2602. The
LIN bus can transmit and receive information.
Wake-up from Stop mode is initiated by a wake-up
interrupt. Wake-up from Sleep mode is done by a reset and
the voltage regulator is turned back on.
The high side switches are active and have PWM
capability according to the SPI configuration.
The selection of the different modes is controlled by the
MOD1:2 bits in the Mode Control Register (MCR).
The interrupts are generated to report failures for VSUP
over/under-voltage, thermal shutdown, or thermal shutdown
prewarning on the main regulator.
Figure 14 describes how transitions are done between the
different operating modes. Table 6 gives an overview of the
operating modes.
SLEEP MODE
The Sleep mode is a low power mode. From Normal
mode, the device enters into Sleep mode by sending one SPI
command through the Mode Control Register (MCR), or (VDD
low > 150 ms) with VSUV = 0. When in Reset mode, a VDD
RESET MODE
The 33910 enters the Reset mode after a power up. In this
mode, the RST pin is low for 1.0 ms (typical value). After this
delay, it enters the Normal Request mode and the RST pin is
driven high.
under-voltage condition with no VSUP under-voltage (VSUV
=
0) will send the device to Sleep mode. All blocks are in their
lowest power consumption condition. Only some wake-up
sources (wake-up input with or without cyclic sense, forced
wake-up and LIN receiver) are active. The 5.0 V regulator is
OFF. The internal low-power oscillator may be active if the IC
is configured for cyclic-sense. In this condition, one of the
high side switches is turned on periodically and the wake-up
input is sampled.
The Reset mode is entered if a reset condition occurs (VDD
low, watchdog trigger fail, after wake-up from Sleep mode,
Normal Request mode timeout occurs).
NORMAL REQUEST MODE
This is a temporary mode automatically accessed by the
device after the Reset mode, or after a wake-up from Stop
mode.
Wake-up from Sleep mode is similar to a power-up. The
device goes in Reset mode except that the SPI will report the
wake-up source and the BATFAIL flag is not set.
In Normal Request mode, the VDD regulator is ON, the
RESET pin is High, and the LIN is operating in RX Only
mode.
STOP MODE
As soon as the device enters in the Normal Request mode
an internal timer is started for 150 ms (typical value). During
these 150 ms, the MCU must configure the Timing Control
Register (TIMCR) and the Mode Control Register (MCR) with
MOD2 and MOD1 bits set = 0, to enter the Normal mode. If
within the 150 ms timeout, the MCU does not command the
33910 to Normal mode, it will enter in Reset mode. If the
WDCONF pin is grounded in order to disable the watchdog
function, it goes directly in Normal mode after the Reset
mode.
The Stop mode is the second low power mode, but in this
case the 5.0 V regulator is ON with limited current drive
capability. The application MCU is always supplied while the
33910 is operating in Stop mode.
The device can enter into Stop mode only by sending the
SPI command. When the application is in this mode, it can
wake-up from the 33910 side (for example: cyclic sense,
force wake-up, LIN bus, wake inputs) or the MCU side (CS,
RST pins). Wake-up from Stop mode will transition the 33910
to Normal Request mode and generates an interrupt except
if the wake-up event is a low to high transition on the CS pin
or comes from the RST pin.
NORMAL MODE
In Normal mode, all 33910 functions are active and can be
controlled by the SPI interface and the PWMIN pin.
33910
Analog Integrated Circuit Device Data
Freescale Semiconductor
27
FREESCALE [ Freescale ]
