Freescale Semiconductor ColdFire MCF52210 - Manual (Page 458)

Analog-to-Digital Converter (ADC)
MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
26-22 Freescale Semiconductor
Parallel scan can be simultaneous or non-simultaneous. During simultaneous scan, the scans in the two
converters are done simultaneously and always result in simultaneous pairs of conversions, one by
converter A and one by converter B. The two converters share the same start, stop, sync, end-of-scan
interrupt enable control, and interrupt. Scanning in both converters is terminated when either converter
encounters a disabled sample. In non-simultaneous scan, the parallel scans in the two converters are
achieved independently. The two converters have their own start, stop, sync, end-of-scan interrupt enable
controls, and end-of-scan interrupts. Scanning in either converter terminates only when that converter
encounters a disabled sample in its part of SDIS register (DS0-DS3 for A, DS4-DS7 for B).
Figure 26-19. Parallel Mode Operation of the ADC
The ADC can be configured to perform a single scan and halt, perform a scan when triggered, or perform
the scan sequence repeatedly until manually stopped. The single scan (once mode) differs from the
triggered mode only in that SYNC input signals must be re-armed after each using a once mode scan, and
subsequent SYNC inputs are ignored until the SYNC input is re-armed. This arming can occur anytime
after the SYNC pulse occurs, even while the scan it initiated remains in process.
AN3
AN2
AN1
AN0
V+
V
REFL
Channel Select
V–
ADCA
12
Single-Ended vs
Crossbars do
not operate in
Differential
12
+
ADOFS[0:3]
13
Zero Crossing Logic
+
–
ADHLMT[4:7]
>
ADRSLT[0:3]
Zero Crossing
or Error Limit
Interrupt
ADLLMT[4:7]
<
12 12
+
ADOFS[4:7]
13
Zero Crossing Logic
+
–
ADRSLT[4:7]
12
AN7
AN6
AN5
AN4
V+
V
REFL
Channel Select
V–
ADCB
Single-Ended vs
Differential
12
ADHLMT[0:3]
>
ADLLMT[0:3]
<
Test Data
(From CPU)
Test Data
(From CPU)
ADC2
ADC1
ADC0
End of
Scan B
Interrupt
End of
Scan A
Interrupt
IRQ Logi
c
this mode