eQEP Registers
1993
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Enhanced Quadrature Encoder Pulse (eQEP) Module
34.3.21 eQEP Status Register (QEPSTS)
Figure 34-41. eQEP Status Register (QEPSTS) [offset = 3Ah]
15
8
Reserved
R-0
7
6
5
4
3
2
1
0
UPEVNT
FIDF
QDF
QDLF
COEF
CDEF
FIMF
PCEF
R-1
R-0
R-0
R-0
R/W-1
R/W-1
R/W-1
R-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 34-24. eQEP Status Register (QEPSTS) Field Descriptions
Bit
Field
Value
Description
15-8
Reserved
0
Always read as 0.
7
UPEVNT
Unit position event flag.
0
No unit position event is detected.
1
Unit position event is detected. Write 1 to clear.
6
FIDF
Direction on the first index marker. Status of the direction is latched on the first index event marker.
0
Counter-clockwise rotation (or reverse movement) on the first index event.
1
Clockwise rotation (or forward movement) on the first index event.
5
QDF
Quadrature direction flag.
0
Counter-clockwise rotation (or reverse movement).
1
Clockwise rotation (or forward movement).
4
QDLF
eQEP direction latch flag. Status of direction is latched on every index event marker.
0
Counter-clockwise rotation (or reverse movement) on index event marker.
1
Clockwise rotation (or forward movement) on index event marker.
3
COEF
Capture overflow error flag.
0
Sticky bit, cleared by writing 1.
1
Overflow occurred in eQEP Capture timer (QCTMR).
2
CDEF
Capture direction error flag.
0
Sticky bit, cleared by writing 1.
1
Direction change occurred between the capture position event.
1
FIMF
First index marker flag.
0
Sticky bit, cleared by writing 1.
1
Set by first occurrence of index pulse.
0
PCEF
Position counter error flag. This bit is not sticky and it is updated for every index event.
0
No error occurred during the last index transition.
1
Position counter error.