Chapter 13 Analog-to-Digital Converter (ADC12B16CV1) Block Description
MC9S12XE-Family Reference Manual , Rev. 1.07
530
Freescale Semiconductor
13.3.2.7
ATD Status Register 0 (ATDSTAT0)
This register contains the Sequence Complete Flag, overrun flags for external trigger and FIFO mode, and
the conversion counter.
Read: Anytime
Write: Anytime (No effect on (CC3, CC2, CC1, CC0))
Module Base + 0x0006
7
6
5
4
3
2
1
0
R
SCF
0
ETORF
FIFOR
CC3
CC2
CC1
CC0
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 13-9. ATD Status Register 0 (ATDSTAT0)
Table 13-16. 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
associatedconversioncompleteflag(CCF)hasbeencleared.ThisflagismostusefulwhenusingtheFIFOmode
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)