33991 View Datasheet(PDF) - Motorola => Freescale
Part Name
Description
Manufacturer
33991 Datasheet PDF : 36 Pages
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Freescale Semiconductor, Inc.
SO Communication
When the CS pin is pulled low, the internal status word
register is loaded into the output register and the fault data is
clocked out MSB (OD15) first. Following a CS transition 0 to 1,
the device determines if the message shift was a valid length
and if so, latches the data into the appropriate registers. A valid
message length is greater than 0 bits and a multiple of 16 bits.
At this time, the SO pin is tri-stated and the fault status register
is now able to accept new fault status information. If the
message length is determined to be invalid, the status
information is not cleared. It is transmitted again during the next
SPI message.
Any bits clocked out of the SO pin after the first sixteen, is
representative of the initial message bits clocked into the SI pin.
That is due to the CS pin first being transitioned to a logic [0].
This feature is useful for daisy chaining devices as well as
message verification.
Table 12. Status Output Register
Read
OD15
ST15
OD14
ST14
OD13
ST13
OD12
ST12
OD11
ST11
OD10
ST10
OD9 OD8 OD7 OD6 OD5 OD4 OD3 OD2 OD1 OD0
ST9 ST8 ST7 ST6 ST5 ST4 ST3 ST2 ST1 ST0
These are read-only bits.
ST15–ST8—Bits representing the eight bits from the RTZ
accumulator as determined by the status of bits RZ2 and RZ3
of the RTZR, defined in Table 8. These bits represent the
integrated signal present on the non-driven coil during an RTZ
event. These bits will be logic [0] after power-on reset, or after
the RST pin transitions from logic [0] to [1]. After an RTZ event,
they will represent the last RTZ accumulator result before the
RTZ was stopped.
ST7–Calibrated Clock out of Specification—A logic [1] on
this bit indicates the clock count calibrated to a value outside of
the expected range, and given the tolerance specified by TCLC
in the SPI Interface Timing table.
• 0 = Clock with in spec
• 1 = Clock out of spec
ST6–Under voltage or over voltage Indication—A logic [1] on
this bit indicates the VPWR voltage fell to a level below the
VPWRUV, or it exceeded an upper limit of VPWROV, as specified
in the Static Electrical Characteristics table, since the last SPI
communication. An under voltage event is just flagged, while an
over voltage event automatically disables the driver outputs.
Because the pointer may not be in the expected position, the
master may want to re-calibrate the pointer position with a RTZ
command after the voltage returns to a normal level. For an
over voltage event, both gauges must be re-enabled as soon as
this flag returns to logic [0]. The state machine continues to
operate properly as long as VDD is within the normal range.
• 0 = Normal range
• 1 = Battery voltage fell below VPWRUV, or exceeded
VPWROV
ST5–Gauge 1—Movement since last SPI communication. A
logic [1] on this bit indicates the Gauge 1 pointer position has
changed since the last SPI command. This allows the master to
confirm the pointer is moving as commanded.
• 0 = Gauge 1 position has not changed since the last SPI
command
• 1 = Gauge 1 pointer position has changed since the last
SPI command
ST4—Gauge 0—Movement since last SPI communication.
A logic [1] on this bit indicates the Gauge 0 pointer position
has changed since the last SPI command. The master confirms
the pointer is moving as commanded.
• 0 = Gauge 0 position has not changed since the last SPI
command
• 1 = Gauge 0 pointer position has changed since the last
SPI command
ST3–RTZ1—Enabled successful or disabled. A logic [1] 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
ST2–RTZ0—Enabled successful or disabled. A logic [1] 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.
• 0 = Return to zero disabled
• 1 = Return to zero enabled successful
ST1–Gauge 1—Junction over temperature. A logic [1] on this
bit indicates coil drive circuitry dedicated to drive Gauge 1 has
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
condition has been reached
MOTOROLA ANALOG INTEGRATED CIRFCoUIrTMDEoVrICeEIDnAfoTArmation On This Product,
Go to: www.freescale.com
33991
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