UM10360 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
User manual Rev. 3 — 19 December 2013 553 of 841
NXP Semiconductors
UM10360
Chapter 26: LPC176x/5x Quadrature Encoder Interface (QEI)
26.6.3.5 QEI Position Compare register 2 (CMPOS2 - 0x400B C01C)
This register contains a position compare value. This value is compared against the
current value of the position register. Interrupts can be enabled to interrupt when the
compare value is equal to the current value of the position register.
26.6.3.6 QEI Index Count register (INXCNT - 0x400B C020)
This register contains the current value of the index counter. It is updated when an index
count occurs. This can be an increment when the position counter overflows the MAXPOS
value or a decrement when the position counter underflows zero, depending on the
direction of rotation. In case (re)calibration occurs due to an index pulse, the
over/underflow is forced internally.
26.6.3.7 QEI Index Compare register (INXCMP - 0x400B C024)
This register contains an index compare value. This value is compared against the current
value of the index count register. Interrupts can be enabled to interrupt when the compare
value is equal to the current value of the index count register.
26.6.3.8 QEI Timer Reload register (QEILOAD - 0x400B C028)
This register contains the reload value of the velocity timer. When the timer (QEITIME)
overflows or the RESV bit is asserted, this value is loaded into the timer (QEITIME).
26.6.3.9 QEI Timer register (QEITIME - 0x400B C02C)
This register contains the current value of the velocity timer. When this timer overflows the
value of velocity counter (QEIVEL) is stored in the velocity capture register (QEICAP), the
velocity counter is reset to zero, the timer is reloaded with the value stored in the velocity
reload register (QEILOAD), and the velocity interrupt (TIM_Int) is asserted.
Table 491: QEI Position Compare register 2 (CMPOS2 - address 0x400B C01C) bit description
Bit Symbol Description Reset
value
31:0 - Position compare value 2. 0
Table 492: QEI Index Count register (INXCNT - address 0x400B C020) bit description
Bit Symbol Description Reset
value
31:0 - Current index counter value. 0
Table 493: QEI Index Compare register (INXCMP - address 0x400B C024) bit description
Bit Symbol Description Reset
value
31:0 - Index compare value. 0
Table 494: QEI Timer Load register (QEILOAD - address 0x400B C028) bit description
Bit Symbol Description Reset
value
31:0 - Velocity timer reload value. 0
To Next Page
Loading...
Need help?
General
