Texas Instruments TMS320 2806 Series, Technical Reference Manual

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7.10.2.12 QDECCTL Register (Offset = 14h) [reset = 0h]
Quadrature Decoder Control
Figure 7-32. QDECCTL Register
15 14 13 12 11 10 9 8
QSRC SOEN SPSEL XCR SWAP IGATE QAP
R/W-0h R/W-0h R/W-0h R/W-0h R/W-0h R/W-0h R/W-0h
7 6 5 4 3 2 1 0
QBP QIP QSP RESERVED
R/W-0h R/W-0h R/W-0h R-0h
Table 7-17. QDECCTL Register Field Descriptions
Bit Field Type Reset Description
15-14 QSRC R/W 0h Position-counter source selection
Reset type: SYSRSn
0h (R/W) = Quadrature count mode (QCLK = iCLK, QDIR = iDIR)
1h (R/W) = Direction-count mode (QCLK = xCLK, QDIR = xDIR)
2h (R/W) = UP count mode for frequency measurement (QCLK =
xCLK, QDIR = 1)
3h (R/W) = DOWN count mode for frequency measurement (QCLK =
xCLK, QDIR = 0)
13 SOEN R/W 0h Sync output-enable
Reset type: SYSRSn
0h (R/W) = Disable position-compare sync output
1h (R/W) = Enable position-compare sync output
12 SPSEL R/W 0h Sync output pin selection
Reset type: SYSRSn
0h (R/W) = Index pin is used for sync output
1h (R/W) = Strobe pin is used for sync output
11 XCR R/W 0h External Clock Rate
Reset type: SYSRSn
0h (R/W) = 2x resolution: Count the rising/falling edge
1h (R/W) = 1x resolution: Count the rising edge only
10 SWAP R/W 0h CLK/DIR Signal Source for Position Counter
Reset type: SYSRSn
0h (R/W) = Quadrature-clock inputs are not swapped
1h (R/W) = Quadrature-clock inputs are swapped
9 IGATE R/W 0h Index pulse gating option
Reset type: SYSRSn
0h (R/W) = Disable gating of Index pulse
1h (R/W) = Gate the index pin with strobe
8 QAP R/W 0h QEPA input polarity
Reset type: SYSRSn
0h (R/W) = No effect
1h (R/W) = Negates QEPA input
7 QBP R/W 0h QEPB input polarity
Reset type: SYSRSn
0h (R/W) = No effect
1h (R/W) = Negates QEPB input
www.ti.com Enhanced Quadrature Encoder Pulse (eQEP)
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
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TMS320x2806x Microcontrollers 491
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