NXP Semiconductors MPC5644A, Reference Manual, Page: 1194 / 1735

Decimation Filter
MPC5644A Microcontroller Reference Manual, Rev. 6
1194 Freescale Semiconductor
26.4.2.6 Decimation Filter Interface Output Buffer Register (DECFILTER_OB)
8–13 Reserved, should be cleared.
14
PREFILL
Decimation Filter Prefill/Filter control bit
The PREFILL bit selects the Decimation Filter operation mode. For more details, see
Section 26.5.7, Filter prefill control description .
1 Decimation Filter prefill sample
0 Decimation Filter normal sample
15
FLUSH
Decimation Filter Flush control bit
Assertion of the FLUSH bit initializes the Decimation Filter to a initial state, as defined in
Section 26.5.9, Flush command description ”. This bit is self negated and it is cleared only when
the data is read and the flush is executed.
1 Flush request
0 No flush request
16–31
INPBUF[15:0]
Input Buffer Data
The INPBUF[15:0] bit field carries the sample data to be filtered. This data buffer can be written
from the PSI slave-bus interface or by the device slave-bus interface. See
Section 26.5.3, Input
buffer description , for more details.
Address: DECFILTE 0x014 Access: User read only
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
R 0 0 0 0 0 0 0 0 0 0 0 0 OUTTAG[3:0]
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
R OUTBUF[15:0]
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Figure 26-7. Decimation Filter Interface Output Buffer Register (DECFILTER_OB)
Table 26-19. DECFILTER_OB Register Field Descriptions
Field Description
0–11 Reserved, should be cleared.
12–15
OUTTAG[3:0]
Decimation filter output tag bits. The OUTTAG[3:0] bit field is defined as a selector signal and it
is used to identify different destinations for the OUTBUF[15:0] data.
When an eQADC is the PSI block master, it holds the same number used to address the
destination RFIFO.
15–31
OUTBUF[15:0]
Output Buffer Data. The OUTPBUF[15:0] bit field is the result data in the decimation filter Output
Buffer. It represents a fixed point signed number in two’s complement format and is updated only
when a decimated result is ready to be transmitted, meaning it contains the last decimated result
from the filter.
Table 26-18. DECFILTER_IB Register Field Descriptions (continued)
Field Description