NXP Semiconductors MPC5566, Reference Manual

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Enhanced Queued Analog-to-Digital Converter (eQADC)
MPC5566 Microcontroller Reference Manual, Rev. 2
19-72 Freescale Semiconductor
19.4.3.6 CFIFO and Trigger Status
19.4.3.6.1 CFIFO Operation Status
Each CFIFO has its own CFIFO status field. CFIFO status (CFS) can be read from EQADC_CFSSR (refer
to
Section 19.3.2.11, “eQADC CFIFO Status Register (EQADC_CFSR) .” Figure 19-39 and Table 19-45
indicate the CFIFO status switching condition. Refer to Table 19-18 for the meaning of each CFIFO
operation status. The last CFIFO to transfer a command to an on-chip ADC can be read from the LCFT n
( n =0,1) fields (see Section 19.3.2.10, “eQADC CFIFO Status Snapshot Registers 0–2
(EQADC_CFSSRn) .” The last CFIFO to transfer a command to a specific external command buffer can
be identified by reading the EQADC_CFSSR n [LCFTSSI] and EQADC_CFSSR n [ENI] fields (see
Section 19.3.2.10, “eQADC CFIFO Status Snapshot Registers 0–2 (EQADC_CFSSRn) .”
Continuous
Scan Edge No A corresponding edge
occurs. Yes Yes None.
Continuous
Scan Level No Gate is opened. No No The eQADC also stops transfers
from the CFIFO when CFIFO
status changes from triggered
due to the detection of a closed
gate.
5
1
Refer to Section 19.4.3.6.2, “Command Queue Completion Status
,”
for more information on EOQ.
2
Refer to Section 19.4.3.6.3, “Pause Status ,” for more information on pause.
3
The eQADC always stops command transfers from a CFIFO when the CFIFO operation mode is disabled.
4
The eQADC always stops command transfers from a CFIFO when a higher priority CFIFO is triggered. Refer to
Section 19.4.3.2, “CFIFO Prioritization and Command Transfer ,” for information on CFIFO priority.
5
If a closed gate is detected while no command transfers are taking place, it has an immediate effect on the CFIFO
status. If a closed gate is detected during the serial transmission of a command to the external device, it has no effect
on the CFIFO status until the transmission completes.
Table 19-44. CFIFO Scan Trigger Mode—Command Transfer Start/Stop Summary
Trigger Mode
Requires
Asserted SSS
to Recognize
Trigger
Events?
Command Transfer
Start/Restart Condition
Stop on
asserted
EOQ
bit
1
?
Stop on
asserted
Pause
bit
2
?
Other Command Transfer Stop
Condition
3 4