NXP Semiconductors MPC5566, Reference Manual

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Enhanced Queued Analog-to-Digital Converter (eQADC)
MPC5566 Microcontroller Reference Manual, Rev. 2
19-42 Freescale Semiconductor
19.3.3.5 ADC n Offset Calibration Constant Registers (ADC0_OCCR and
ADC1_OCCR)
The ADC n _OCCR contains the offset calibration constant used to fine-tune of ADC0/1 conversion results.
The offset constant is a signed 14-bit integer value. Refer to Section 19.4.5.4, “ADC Calibration Feature ,”
for details about the calibration scheme used in the eQADC.
19.4 Functional Description
The eQADC provides a parallel interface to two on-chip ADCs, and a single master to single slave serial
interface to an off-chip external device. The two on-chip ADCs can access all the analog channels.
Initially, command data is contained in system memory in a user defined data queue structure. Command
data is moved between the user-defined queues and CFIFOs by the host CPU or by the eDMA which
responds to interrupt and eDMA requests generated by the eQADC. The eQADC supports software and
Table 19-32. ADC n _GCCR Field Descriptions
Field Description
0 Reserved.
1–15
GCC n
[0:14]
ADC n gain calibration constant (GCC1) is an unsigned 15-bit fixed pointed number expressed in the
GCC_INT.GCC_FRAC binary format. Use the gain calibration constant to fine-tune ADC n conversion results. The
integer part of the gain constant (GCC_INT) contains a single binary digit while its fractional part (GCC_FRAC)
contains 14 digits. For details about the GCC data format refer to
Section 19.4.5.4.2, “MAC Unit and Operand Data
Format .”
Address: 0x0005 Access: R/W
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
R 0 0
OCC0
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
R 0 0
OCC1
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Figure 19-23. ADC n Offset Calibration Constant Registers (ADC n _OCCR)
Table 19-33. ADC n _OCCR Field Descriptions
Field Description
0–1 Reserved.
2–15
OCC n
[0:13]
ADC n offset calibration constant. Contains the offset calibration constant used to fine-tune ADC n conversion results.
Use the two’s complement representation for expressing negative values.