Chapter 13 Analog-to-Digital Converter (ADC12B16CV1)
MC9S12XE-Family Reference Manual , Rev. 1.19
516
Freescale Semiconductor
Write: Anytime (No effect on (CC3, CC2, CC1, CC0))
13.3.2.8
ATD Compare Enable Register (ATDCMPE)
Writes to this register will abort current conversion sequence.
Read: Anytime
Write: Anytime
Table 13-17. ATDSTAT0 Field Descriptions
Field
Description
7
SCF
Sequence Complete Flag
— This flag is set upon completion of a conversion sequence. If conversion
sequences are continuously performed (SCAN=1), the flag is set after each one is completed. This flag is cleared
when one of the following occurs:
A) Write “1” to SCF
B) Write to ATDCTL5 (a new conversion sequence is started)
C) If AFFC=1 and read of a result register
0 Conversion sequence not completed
1 Conversion sequence has completed
5
ETORF
External Trigger Overrun Flag
— While in edge trigger mode (ETRIGLE=0), if additional active edges are
detected while a conversion sequence is in process the overrun flag is set. This flag is cleared when one of the
following occurs:
A) Write “1” to ETORF
B) Write to ATDCTL0,1,2,3,4, ATDCMPE or ATDCMPHT (a conversion sequence is aborted)
C) Write to ATDCTL5 (a new conversion sequence is started)
0 No External trigger over run error has occurred
1 External trigger over run error has occurred
4
FIFOR
Result Register Over Run Flag
— This bit indicates that a result register has been written to before its
associated conversion complete flag (CCF) has been cleared. This flag is most useful when using the FIFO mode
because the flag potentially indicates that result registers are out of sync with the input channels. However, it is
also practical for non-FIFO modes, and indicates that a result register has been over written before it has been
read (i.e. the old data has been lost). This flag is cleared when one of the following occurs:
A) Write “1” to FIFOR
B) Write to ATDCTL0,1,2,3,4, ATDCMPE or ATDCMPHT (a conversion sequence is aborted)
C) Write to ATDCTL5 (a new conversion sequence is started)
0 No over run has occurred
1 Overrun condition exists (result register has been written while associated CCFx flag was still set)
3–0
CC[3:0]
Conversion Counter
— These 4 read-only bits are the binary value of the conversion counter. The conversion
counter points to the result register that will receive the result of the current conversion. E.g. CC3=0, CC2=1,
CC1=1, CC0=0 indicates that the result of the current conversion will be in ATD Result Register 6. If in non-FIFO
mode (FIFO=0) the conversion counter is initialized to zero at the begin and end of the conversion sequence. If
in FIFO mode (FIFO=1) the register counter is not initialized. The conversion counters wraps around when its
maximum value is reached.
Aborting a conversion or starting a new conversion clears the conversion counter even if FIFO=1.
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:
S12XE
products
in
208
MAPBGA
packages
