Datasheet

FUNCTIONAL DEVICE OPERATION
ADC SUBSYSTEM
Analog Integrated Circuit Device Data
Freescale Semiconductor 105
MC13892
ADC ARBITRATION
The ADC converter and its control is based on a single ADC converter core with the possibility to store two requests, and to
store both their results as shown in Figure 27. This allows two independent pieces of software to perform ADC requests.
Figure 27. ADC Request Handling
The programming for the two requests, the one to the 'ADC' and to the 'ADC BIS', uses the same SPI registers. The write
access to the control of 'ADC BIS' is handled via the ADCBISn bits located at bit position 23 of the ADC control registers, which
functions as an extended address bit. By setting this bit to a 1, the control bits which follow are destined for the 'ADC BIS'.
ADCBISn will always read back 0 and there is no read access to the control bits related to 'ADC BIS'. The read results from the
'ADC' and 'ADC BIS' conversions are available in two separate registers.
The following diagram schematically shows how the ADC control and result registers are set-up.
Table 93. Die Temperature Voltage Reading
Parameter Minimum Typical Maximum Unit
Die Temperature Read Out Code at 25 °C
– 680 – Decimal
Temperature change per LSB
– +0.4244 °C – °C/LSB
Slope error
– – 5.0 %
Table 94. ADC Channel 7 Scaling Selection
ADIN7DIV ADIN7SEL1 ADIN7SEL0 Channel 7 Routing and Scaling
0 0 0
General purpose input ADIN7, Scaling = 1
1 0 0
General purpose input ADIN7, Scaling = 1 / 2
x 0 1
Die temperature
x 1 0
UID pin voltage, Scaling = 1 / 2
0 1 1
General purpose input ADIN7B, Scaling = 1
1 1 1
General purpose input ADIN7B, Scaling = 1 / 2