UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
905 of 1269
NXP Semiconductors
UM10503
Chapter 31: LPC43xx Quadrature Encoder Interface (QEI)
31.6.3.3 QEI Interrupt Status register
This register provides the status of the encoder interface and the current set of interrupt
sources that are asserted to the controller. Bits set to 1 indicate the latched events that
have occurred; a zero bit indicates that the event in question has not occurred. Writing a 0
to a bit position clears the corresponding interrupt.
8
POS2_INT
Indicates that the position 2 compare value is equal to the current position.
0
9
REV0_INT
Indicates that the index compare value is equal to the current index count.
0
10
POS0REV_INT
Combined position 0 and revolution count interrupt. Set when both the POS0_INT bit is
set and the REV0_INT is set.
0
11
POS1REV_INT
Combined position 1 and revolution count interrupt. Set when both the POS1_INT bit is
set and the REV1_INT is set.
0
12
POS2REV_INT
Combined position 2 and revolution count interrupt. Set when both the POS2_INT bit is
set and the REV2_INT is set.
0
13
REV1_INT
Indicates that the index 1 compare value is equal to the current index count.
0
14
REV2_INT
Indicates that the index 2 compare value is equal to the current index count.
0
15
MAXPOS_INT
Indicates that the current position count goes through the MAXPOS value to zero in
forward direction, or through zero to MAXPOS in backward direction.
0
31:16
-
Reserved
0
Table 747: QEI Interrupt Enable Set register (IES - address 0x400C 6FDC) bit description
Bit
Symbol
Description
Reset
value
Table 748: QEI Interrupt Status register (INTSTAT - address 0x400C 6FE0) bit description
Bit
Symbol
Description
Reset
value
0
INX_INT
Indicates that an index pulse was detected.
0
1
TIM_INT
Indicates that a velocity timer overflow occurred
0
2
VELC_INT
Indicates that captured velocity is less than compare velocity.
0
3
DIR_INT
Indicates that a change of direction was detected.
0
4
ERR_INT
Indicates that an encoder phase error was detected.
0
5
ENCLK_INT
Indicates that and encoder clock pulse was detected.
0
6
POS0_INT
Indicates that the position 0 compare value is equal to the current position.
0
7
POS1_INT
Indicates that the position 1compare value is equal to the current position.
0
8
POS2_INT
Indicates that the position 2 compare value is equal to the current position.
0
9
REV0_INT
Indicates that the index compare value is equal to the current index count.
0
10
POS0REV_INT Combined position 0 and revolution count interrupt. Set when both the POS0_INT bit is
set and the REV0_INT is set.
0
11
POS1REV_INT Combined position 1 and revolution count interrupt. Set when both the POS1_INT bit is
set and the REV1_INT is set.
0
12
POS2REV_INT Combined position 2 and revolution count interrupt. Set when both the POS2_INT bit is
set and the REV2_INT is set.
0
13
REV1_INT
Indicates that the index 1 compare value is equal to the current index count.
0
14
REV2_INT
Indicates that the index 2 compare value is equal to the current index count.
0
15
MAXPOS_INT
Indicates that the current position count goes through the MAXPOS value to zero in
forward direction, or through zero to MAXPOS in backward direction.
0
31:16
-
Reserved
0