FXTH87xx11 and FXTH87xx12 Embedded Firmware User Guide, Rev. 2.1
14
Freescale Semiconductor, Inc.
Firmware Functions
— If the ADC value is over or under the normal operating condition, the “temperature error” status
flag will be set. The expected temperature result will be forced to either “0” or “4095.” (rail
high or rail low).
— If the ADC times out with no result, the “ADC error” status flag will be set.
•
Stack size:
17 bytes
•
Approx. Duration:
219 usec
•
Power Management:
This function requires the core to be configured for STOP4 mode and
running at full bus speed.
•
Interrupt Management:
This function utilizes the ADC interrupt to wake-up from STOP mode.
•
Resources:
ADC, bandgap.
•
Input Parameters:
— UINT16 *u16UUMA: Pointer to Universal Uncompensated Measurement Array (as described
). Only the 12-bit uncompensated temperature result will be updated.
•
Returns
: UINT8 u8Status:Valid error flags/outputs are described in
.
WARNING
The Bandgap bit (BIT0 in the SPMSC1 register) must be set prior to calling
this function for results to be valid.
Table 10. Valid output conditions for TPMS_READ_TEMPERATURE
u8Status Value
Measurement Value
Condition
$40
$0FFF
Uncompensated temperature reading outside of valid range (high).
$40
$0000
Uncompensated temperature reading outside of valid range (low).
$60
$0FFF
Uncompensated temperature reading outside of valid range (high),
and LVWF set.
$60
$0000
Uncompensated temperature reading outside of valid range (low),
and LVWF set.
$80
Undefined
Uncompensated temperature reading not acquired.
$A0
Undefined
Uncompensated temperature reading not acquired, and LVWF set.
$00
Between $0001 - $0FFE
Valid uncompensated temperature reading.
$20
Between $0001 - $0FFE
Valid uncompensated temperature reading, LVWF set.
