NXP Semiconductors MPC5644A, Reference Manual, Page: 1183 / 1735

Decimation Filter
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 1183
20–23
DEC_RATE[3:0]
Decimation Rate Selection. The DEC_RATE[3:0] field selects the decimation rate used by the
Decimation Filter. The decimation rate defines the number of data samples from the master block
that is required to generate one decimated result in the Decimation Filter output.
24
SDIE
Integrator Data Interrupt Enable. The SDIE field enables output buffer interrupts due to integrator
data result being ready (at registers DECFILTER_FINTVAL and DECFILTER_FINTCNT):
1 Integration ready causes an output interrupt
0 Integration ready does not cause an output interrupt.
25
DSEL
DMA Selection. The DSEL bit determines whether the data transfers — to the input buffer (write
to) and from the output buffer (read from) — are performed by DMA requests or by interrupt
requests. This bit can also be active when PSI input is selected with Enhanced Debug (ISEL = 0,
EDME = 1), in which case the input buffer generates read requests only (see
Section 26.5.14,
Enhanced debug monitor description ”).
1 DMA requests are generated
0 Interrupt requests are generated
26
IBIE
Input Buffer Interrupt Request Enable. The IBIE bit enables the Decimation Filter to generate
interrupt requests when:
• device slave-bus input is selected (ISEL = 1) and DSEL = 0 when the input buffer is available
to receive new data;
• PSI input is selected with Enhanced debug (ISEL = 0, EDME = 1) and DSEL = 0 when the
input buffer has data to be read by the device CPU.
1 Input Buffer Interrupt Request Enabled
0 Input Buffer Interrupt Request Disabled
27
OBIE
Output Buffer Interrupt Request Enable
The OBIE bit enables the Decimation Filter interrupt requests when outputs are directed to the
device slave-bus (ISEL!= MIXM) and DMA is not selected (DSEL = 0).
1 Output Buffer Interrupt Request Enabled
0 Output Buffer Interrupt Request Disabled
28
EDME
Enhanced Debug Monitor Enable
The EDME bit defines the enhanced debug monitor when input selection is from PSI (ISEL = 0).
In this case, the raw data fed from the PSI Master block is also, in parallel, made available in the
register DECFILTER_EDID (see
Section 26.5.14, Enhanced debug monitor description ”),
generating and input interrupt or DMA request.
1 Enhanced debug monitor enabled (read requests of input data from master block enabled)
0 Enhanced debug monitor disabled
Table 26-4. DECFILTER_MCR Register Field Descriptions (continued)
Field Description
Table 26-9. DEC_RATE[3:0] definition
DEC_RATE[3:0] Description
0000 No Decimation: one filter output for each sample input
0001 – 1111 One filter output for each (D1) sample inputs