Texas Instruments Tiva TM4C123GH6PM, User Manual

Page: 182 / 352

Quadrature Encoder (QEI)
Description:
This sets the current position of the encoder; the encoder position will then be measured
relative to this value.
Returns:
None.
16.2.1.12 ROM_QEIVelocityConfigure
Configures the velocity capture.
Prototype:
void
ROM_QEIVelocityConfigure(uint32_t ui32Base,
uint32_t ui32PreDiv,
uint32_t ui32Period)
ROM Location:
ROM_APITABLE
is an array of pointers located at
0x0100.0010
.
ROM_QEITABLE
is an array of pointers located at
ROM_APITABLE[9]
.
ROM_QEIVelocityConfigure
is a function pointer located at
ROM_QEITABLE[9]
.
Parameters:
ui32Base is the base address of the quadrature encoder module.
ui32PreDiv specifies the predivider applied to the input quadrature signal before it is counted;
can be one of QEI_VELDIV_1 , QEI_VELDIV_2 , QEI_VELDIV_4 , QEI_VELDIV_8 ,
QEI_VELDIV_16 , QEI_VELDIV_32 , QEI_VELDIV_64 , or QEI_VELDIV_128 .
ui32Period specifies the number of clock ticks over which to measure the velocity; must be
non-zero.
Description:
This will configure the operation of the velocity capture portion of the quadrature encoder. The
position increment signal is predivided as specified by
ui32PreDiv before being accumulated
by the velocity capture. The divided signal is accumulated over ui32Period system clock before
being saved and resetting the accumulator.
Returns:
None.
16.2.1.13 ROM_QEIVelocityDisable
Disables the velocity capture.
Prototype:
void
ROM_QEIVelocityDisable(uint32_t ui32Base)
ROM Location:
ROM_APITABLE
is an array of pointers located at
0x0100.0010
.
ROM_QEITABLE
is an array of pointers located at
ROM_APITABLE[9]
.
ROM_QEIVelocityDisable
is a function pointer located at
ROM_QEITABLE[8]
.
182 April 8, 2013