PXR40RM Datasheet, PDF (1137/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

Decimation Filter
Table 28-13. DECFILT_x_FINTVAL Field Descriptions
Field
Description
0–31 Integration Sum Value—The SUM_VALUE[31:0] field holds the sum of filtered output values. The 17 most
SUM_VALUE significant bits hold the integer part, and the 15 least significant ones the fractional part of the integration value.
The control of the integration sum and update of this register is determined by the register DECFILT_x_MXCR
(see Section 28.2.2.3, Decimation Filter Module Extended Configuration Register (DECFILT_x_MXCR)). The
register is updated only upon an integration output request.
SUM_VALUE should be taken as an unsigned number when the integrator is configured for absolute operation
(DECFILTER_MXCR bit SSIG=0), and a two’s complement signed number otherwise.
Note: If SSAT=0, DECFILT_x_FINTVAL holds the integration sum modulo 2¹⁷ (considering the 15-bit fractional
part).
Note: If SSAT=1, the integration sum is saturated, so that if the accumulation overflows DECFILT_x_FINTVAL
holds the value 0xFFFFFFFF for absolute integration (SSIG=0), or values 0x7FFFFFFF (positive
saturation) and 0x80000000 (negative saturation) for signed integration (SSIG=1).
28.2.2.11 Decimation Filter Final Integration Count Value Register
(DECFILT_x_FINTCNT)
Address: DECFILT_x_BASE + 0x0E4
Access: User read only
0
1
2
3
4
5
6
7
8
9
10 11 12 13
14
15
R
COUNT[31:16]
W
Reset 0
00
000
000
00
0
00
0
0
16 17 18 19 20 21 22 23 24 25 26 27 28 29
30
31
R
COUNT[15:0]
W
Reset 0
00
000
000
00
0
00
0
0
Figure 28-12. Decimation Filter Final Integration Count Value Register (DECFILT_x_FINTCNT)
Table 28-14. DECFILT_x_FINTCNT Field Descriptions
Field
0–31
COUNT
Description
Integration Count Value—The COUNT field holds the count of filtered outputs integrated. The control of the
integration sum and update of this register is determined by the register DECFILT_x_MXCR. The register is
updated together with DECFILT_x_FINTVAL, only upon an integration output request.
Freescale Semiconductor
PXR40 Microcontroller Reference Manual, Rev. 1
28-23