UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
904 of 1269
NXP Semiconductors
UM10503
Chapter 31: LPC43xx Quadrature Encoder Interface (QEI)
31.6.3 Interrupt registers
31.6.3.1 QEI Interrupt Enable Clear register
Writing a 1 to a bit in this register clears the corresponding bit in the QEI Interrupt Enable
register (QEIIE).
31.6.3.2 QEI Interrupt Enable Set register
Writing a 1 to a bit in this register sets the corresponding bit in the QEI Interrupt Enable
register (QEIIE).
Table 746: QEI Interrupt Enable Clear register (IEC - address 0x400C 6FD8) bit description
Bit
Symbol
Description
Reset
value
0
INX_EN
Indicates that an index pulse was detected.
0
1
TIM_EN
Indicates that a velocity timer overflow occurred
0
2
VELC_EN
Indicates that captured velocity is less than compare velocity.
0
3
DIR_EN
Indicates that a change of direction was detected.
0
4
ERR_EN
Indicates that an encoder phase error was detected.
0
5
ENCLK_EN
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 0 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
0
INX_EN
Indicates that an index pulse was detected.
0
1
TIM_EN
Indicates that a velocity timer overflow occurred
0
2
VELC_EN
Indicates that captured velocity is less than compare velocity.
0
3
DIR_EN
Indicates that a change of direction was detected.
0
4
ERR_EN
Indicates that an encoder phase error was detected.
0
5
ENCLK_EN
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 1 compare value is equal to the current position.
0