Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor
MC9S12C-Family / MC9S12GC-Family
239
Rev 01.24
8.3.2.8
Reserved Register (ATDTEST0)
Read: Anytime, returns unpredictable values
Write: Anytime in special modes, unimplemented in normal modes
NOTE
Writing to this registers when in special modes can alter functionality.
4
FIFOR
FIFO 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) Start a new conversion sequence (write to ATDCTL5 or external trigger)
0 No over run has occurred
1 An over run condition exists
2–0
CC[2:0]
Conversion Counter
— These 3 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. For example, 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 by write to an ATDCTL register (ATDCTL5-2) clears the
conversion counter even if FIFO=1.
Module Base + 0x0008
7
6
5
4
3
2
1
0
R
U
U
U
U
U
U
U
U
W
Reset
1
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 8-10. Reserved Register (ATDTEST0)
Table 8-13. ATDSTAT0 Field Descriptions (continued)
Field
Description
Summary of Contents for MC9S12C Family
Page 689: ......