mc33991dwr2 Freescale Semiconductor, Inc, mc33991dwr2 Datasheet - Page 19

• Manufacturer Part Number: mc33991dwr2
• Description: Gauge Driver Integrated Circuit
• Manufacturer: Freescale Semiconductor, Inc

• 0 = Gauge 1 position has not changed since the last SPI
• 1 = Gauge 1 pointer position has changed since the last
A logic [1] on this bit indicates the Gauge 0 pointer position
has changed since the last SPI command. The master
confirms that the pointer is moving as commanded.
• 0 = Gauge 0 position has not changed since the last SPI
• 1 = Gauge 0 pointer position has changed since the last
on this bit indicates Gauge 1 is in the process of returning to
the zero position as requested with the RTZ command. This
bit continues to indicate a logic [1] until the SPI message
following a detection of the zero position, or the RTZ feature
is commanded OFF using the RTZ message.
• 0 = Return to Zero disabled
• 1 = Return to Zero enabled successful
on this bit indicates Gauge 0 is in the process of returning to
the zero position as requested with the RTZ command. This
bit continues indicating a logic [1] until the SPI message
following a detection of the zero position, or the RTZ feature
is commanded OFF, using the RTZ message.
STATE MACHINE OPERATION
velocity and acceleration, and deceleration. It is the purpose
of the stepper motor state machine is to drive the motor with
maximum performance, while remaining within the motor’s
velocity and acceleration constraints.
constantly to the maximum velocity, then decelerate and stop
at the desired position. During the deceleration phase, the
motor should not exceed the maximum deceleration. A
Analog Integrated Circuit Device Data
Freescale Semiconductor
command
SPI command
ST4–Gauge 0— Movement since last SPI communication.
command
SPI command
ST3–RTZ1—Enabled successful or disabled. A logic [1]
ST2–RTZ0—Enabled successful or disabled. A logic [1]
The two-phase stepper motor is defined as maximum
When commanded, the motor should accelerate
DEVICE FUNCTIONAL DESCRIPTION
• 0 = Return to Zero disabled
• 1 = Return to Zero enabled successful
this bit indicates coil drive circuitry dedicated to drive Gauge
1 exceeded the maximum allowable junction temperature
since the last SPI communication. Additionally, the same
indication signals the circuitry Gauge 1 is disabled. It is
recommended the pointer be re-calibrated using the RTZ
command after re-enabling the gauge using the PECR
command. This bit remains logic [1] until the gauge is
enabled.
• 0 = Temperature within range
• 1 = Gauge 1 maximum allowable junction temperature
this bit indicates coil drive circuitry dedicated to drive Gauge
0 exceeded the maximum allowable junction temperature
since the last SPI communication. Additionally, the same
indication signals the circuitry Gauge 0 is disabled. It is
recommended the pointer be re-calibrated using the RTZ
command after re-enabling the gauge, using the PECR
command. This bit remains logic [1] until the gauge is re-
enabled.
• 0 = Temperature within range
• 1 = Gauge 0 maximum allowable junction temperature
required function of the state machine is to ensure the
deceleration phase begins at the correct time, or position.
microstepped with 24 steps per electrical revolution. See
Figure 6. A complete electrical revolution results in two
degrees of pointer movement. There is a second and smaller
state machine in the IC controlling these microsteps. This
state machine receives clockwise or counter-clockwise index
commands at intervals, stepping the motor in the appropriate
direction by adjusting the current in each coil. Normalized
values provided in Table 13.
ST1–Gauge 1 Junction over temperature. A logic [1] on
condition has been reached
ST0–Gauge 0— Junction over temperature. A logic [1] on
condition has been reached
During normal operation, both stepper motor rotors are
TIMING DESCRIPTIONS AND DIAGRAMS
DEVICE FUNCTIONAL DESCRIPTION
33991
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