QEP (正交编码器脉冲)

简介

Quadrature Encoder Pulse (QEP) 正交编码器脉冲配合外部正交码盘，通过检测电机编码 输出信号，获取电机转速、位置、方向等信号，用于高性能的位置及速度控制系统。

功能概述

  • 兼容 CW/CCW 格式信号、方向脉冲格式信号输入

  • 支持独立的 T 法测速，单位距离可通过软件编程

  • 支持独立的 M 法测速，单位时间可通过软件编程

  • 支持失速检测

  • 支持内部计数器的多种复位模式、初始化模式、锁存模式

  • 内置位置计数比较功能，比较匹配后送出可扩展宽度电平于 INDEX 或 STROBE 引脚

  • 支持 A、B、INDEX 相输入源来自芯片内部 SRPWM、ACMP 模块，完成芯片内部自测

  • 除了编码器 A、B、IINDEX 相信号，还支持 STROBE 相信号做位置指示；该 STROBE信号同样可来自 SRPWM 模块

  • 支持管脚信号滤波

输入选择及模式适配处理单元（PROC）

QEP 模块兼容 CW/CCW 模式输入，将 CW/CCW 信号格式转换为方向脉冲模式。并且对 CW/CCW 模式下的默认值也做了 0/1 两种情况兼容(QMA)， 完成 CW/CCW 信号对内部位置计数值的控制； 兼容方向脉冲模式输入(SWAP)。兼容 A/B 相任意一路为方向指示信号，另一路作为脉冲信号；

适配处理单元拥有以下计数模式:

  • 正交时钟模式：输入 A、B 为相差 90°的信号，硬件通过相位差判断计数方向，计数脉冲为 A/B 的上下沿；

  • 方向计数模式：输入信号 A 的上下沿代表了计数脉冲，B 信号代表了计数方向，高为正方向，低为反方向；

  • 增计数模式：固定方向为 1（正向），计数脉冲为交换后 A 信号上升沿或双沿；

  • 减计数模式：固定方向为 0（反向），计数脉冲为交换后 A 信号上升沿或双沿；

不同的模式下处理单元接收A/B相信号，按照相应规则处理后吐出QCLK供后面模块使用。

../_images/qep1.png
库函数功能:

  • QEP_setDecoderConfig() 设置编码器配置与模式

  • QEP_setQMAModuleMode() 设置信号源的“空闲/无效状态”

捕获功能(T法测速)

T法示意图:

../_images/EQEP_T.png

T 法测速原理为预设单位距离，测量该单位距离所需时长即可得到转速：用高频时钟量出相邻两个编码器边沿之间隔了多长时间，速度与这个周期成反比。QEP 为此专门有一个边沿捕获单元(capture),全部硬件自动完成，不需要软件在 GPIO中断里打时间戳。

QEP 边沿捕获单元部件

部件

作用

捕获定时器

自由运行计数,时钟 = SYSCLK/CCPS(CCPS 分频)

捕获定时器锁存

QCLK 边沿到来瞬间,cnt 的值被硬件锁进去同时被清除开始新一轮计时

捕获周期寄存器

记录相邻两次捕获事件之间的定时器计数差

捕获周期锁存

单元位置事件(unit position event,UPPS 分频)时锁存捕获周期
换算成转速(正交模式):

  • QCLK 是编码器解码后的时钟，频率 = 4 × 编码器线频(4X 模式下每线 4 个 QCLK)。测得 QCLK 周期为 T_qclk， 则n(转/秒) = 1 / (4 × PPR × T_qclk),PPR = 编码器每转脉冲线数。

  • 数值例子：PPR=1000,测得 T_qclk = 25µs → QCLK=40kHz → 线频=10kHz → n = 1/(4×1000×25µs) = 10 转/秒 = 600 RPM。

库函数功能:

  • QEP_setCaptureConfig() — 对应 CCPS/UPPS 两个分频;

  • QEP_getCaptureTimer()— 对应 QCTMR 当前值;

  • QEP_getCapturePeriod() — 对应 QCPRD;

  • QEP_getCaptureTimerLatch() / QEP_getCapturePeriodLatch() — 对应 QCTRL/QCPRDLAT 两个硬件锁存值。

位置计数器(M法测速)

M法示意图：

../_images/EQEP_M.png

M法测速原理为预设单位时间，测量该单位时间内所前进距离即可得到转速:在固定时间窗内,统计位置计数器的增量(即该窗口内来过的正交边沿数),用”位置增量 ÷ 时间”得到转速。它与 T 法(测周法,由边沿捕获单元实现)方向相反:一个数脉冲,一个测脉冲间隔。

M 法测速相关部件

部件

作用

位置计数器PCCU

对解码后的时钟计数,带方向,正转加、反转减

单元定时器 UTIME

自由运行的 32 位定时器,时钟为 SYSCLKOUT,计到 UPRD 时产生**单元超时事件**

位置锁存

单元超时瞬间,PCCU的当前值被硬件锁存,作为窗口结束时刻的位置快照

UTO 中断

单元超时中断,软件在中断里读取锁存值并计算速度
工作流程:

  • 使能单元定时器,设定周期 QUPRD(即测速窗口 T);电机转动,位置计数器 QPOSCNT 连续增减;每当单元定时器计时到 QUPRD,硬件**同时**完成两件事:把 QPOSCNT锁存到 QPOSLAT,并产生 UTO 中断,定时器归零重新开始;

软件在 UTO 中断中计算:

  • ΔP = QPOSLAT(本次) − QPOSLAT(上次),得到一个窗口内的位置增量,代入公式得到转速,窗口周而复始。

速度计算:

  • 设编码器每转 PPR 线,4X 模式下每转位置计数为4 × PPR,测速窗口为T:

    n [r/s]  = ΔP / (4 × PPR × T)
n [rpm]  = 60 × ΔP / (4 × PPR × T)
ω [rad/s] = 2π × ΔP / (4 × PPR × T)
ΔP 带符号,方向信息天然包含在内,无需额外判断正反转。

  • 数值示例(PPR = 1000,T = 1 ms,即每转 4000 计数):

    3000 rpm = 50 r/s  →  ΔP = 50 × 4000 × 0.001 = 200 计数
30   rpm = 0.5 r/s →  ΔP = 0.5 × 4000 × 0.001 = 2 计数
6    rpm ≈ 0.1 r/s →  ΔP = 0.4 → 实际只能数到 0 或 1,基本失效
误差分析:

  • 相对误差 ≈ 1/ΔP:转速越高,窗口内计数越多,误差越小—— 这正是 M 法适合高速的原因;

  • 转速低到 ΔP 只有 0~2 个计数时,误差高达 50% 甚至完全无输出, 此时应切换到 T 法(测周法,相对误差 ≈ Tclk/Tp,低速时反而极小);

  • 速度分辨率为 1/(4 × PPR × T) r/s:窗口越长分辨率越好, 但测量延迟和更新率变差——是分辨率与带宽的折中。

库函数功能:

  • QEP_setPositionCounterConfig() 位置计数器复位模式与最大计数配置

  • QEP_enableUnitTimer() / QEP_loadUnitTimer() 使能/装载单元定时器周期(即测速窗口)

  • QEP_getPosition() 读取位置计数器当前值(每个窗口末采样一次即可)

  • QEP_getDirection() 读取当前旋转方向

  • QEP_INT_UNIT_TIME_OUT() 单元超时中断(M 法的采样节拍来源)

比较输出模式

QEP 内部支持对位置计数值进行比对，并将比较结果进行输出到 INDEX 管脚或 STROBE 管脚，告知对应状态。

../_images/compare.png
比较值的设定支持影子加载，可设置以下两种事件作为影子模式下更新条件:

  • 位置计数值为 0 时更新比较值

  • 上一次位置比较匹配成功更新比较值

库函数功能:

  • QEP_enableCompare() 使能位置比较单元(置 CTRL2_CFG 的 CMP_EN 位)，QEP_disableCompare() 禁用。

  • QEP_setCompareConfig() 一次配完比较单元。

    • compareValue 比较匹配值，QPOSCNT 计到它(实际为 +1)就产生匹配事件。

    • config.compareOutputEn 匹配时是否向引脚输出同步脉冲。

    • config.compareOutputPinSel 输出走哪个脚：index 引脚或 strobe。

    • config.Outputpolarity 输出脉冲的极性。

    • config.shadowModeEn + config.shadowSigSel 影子寄存器使能及装载时机：过零时装载(QEP_COMPARE_LOAD_ON_ZERO)或每次匹配后装载(QEP_COMPARE_LOAD_ON_MATCH),避免运行中改值丢匹配。

    • cycles 同步输出脉宽，单位 4×SYSCLKOUT,范围 1~4096,不能写 0。

  • QEP_setComparePulseWidth() 运行中单独更新脉宽。

锁存/复位/初始化模式

三个功能都是围绕位置计数器PCCU的事件驱动机制——区别在于事件发生时对计数器做什么：复位是清零、初始化是装入设定值、锁存是拍快照。

复位(Reset)

复位功能可以在事件触发后将设位置计数器清0。

内部位置计数值拥有多种复位模式:

  • 第一次 INDEX 复位：此模式下位置计数值只在第一次 INDEX 为高时的 A/B 边沿信号进行复位，此后的 INDEX 不触发复位

  • INDEX 复位：此模式下第一次复位发生在 INDEX 为高时的 A/B 边沿处，并记录此时的方向信息，及边沿类别（A 上升沿、A 下降沿、B 上升沿、B 下降沿）;此后的复位发生在 INDEX 为高，若此时方向与记录方向相同，则在相同的边沿信号进行复位，若不同则在相反的边沿信号复位

  • 超时复位：位置计数值在超时中断给出时进行复位

  • 最值复位：注意以上三种模式都存在该复位，只要位置计数值超过预设最值，则复位

库函数功能:

  • QEP_setPositionCounterConfig() 设置复位模式

初始化(Init)

初始化功能可以在事件触发后将设定值装入位置计数器。内部位置计数值支持多种初始化模式有:

  • INDEX 触发

  • STROBE 触发

  • 软件触发

位置计数值的 INDEX 初始化可配模式:

  • 在 INDEX 上升沿初始化

  • 在 INDEX 下降沿初始化

  • INDEX 不影响初始化

位置计数值的 STROBE 初始化可配模式:

  • 在 STROBE 上升沿初始化

  • 正向 STROBE 上升沿初始化或反向 STROBE 下降沿初始

  • STROBE 不影响初始化

软件写 1 到一特定寄存器（cfg2pccu_swi）的写 1 动作触发初始化，该寄存器不会自动清零

库函数功能:

  • QEP_setInitialPosition() 要装入的值，不必是 0,可以是机械标定值。

  • QEP_setPositionInitMode() 选哪个事件触发装入(et6x_qep.h:126-130):index 上升/下降沿、strobe 上升沿、strobe 边沿+方向(QEP_INIT_EDGE_DIR_STROBE 正转沿上升沿、反转沿下降沿)，也可以 index 和 strobe 事件相或组合。

  • QEP_setSWPositionInit() 软件立即触发一次装入。

锁存(Latch)

针对不同事件，可将当前的位置计数值锁存到对目的寄存器:事件瞬间硬件拍快照，主计数器继续跑，软件随时来取，没有“读数时刻和事件时刻不同步”的问题

1.支持位置计数值 INDEX 来临时锁存到相应寄存器 (PCINTILAT) 模式：

  • INDEX 上升沿锁存

  • INDEX 下降沿锁存

  • 标记时刻锁存

  • 不锁存；

2.支持位置计数值的 STROBE 锁存到相应寄存器（PCNTSLAT）模式：

  • STROBE 上升沿锁存

  • 正向时，STROBE 的上升沿锁存；或反向时，STROBE 的下降沿

备注

  • 注意当位置计数值的复位模式为 INDEX 复位，则直接为标记时刻锁存，忽略该配置

  • 标记时刻定义第一次 INDEX 为高时的 A/B 的边沿处，并记录此时的方向信息，及边沿类别（A 上升沿、A 下降沿、B 上升沿、B 下降沿）； 此后在 INDEX 为高电平期间，若方向与记录方向相同，则称相同的边沿信号为标记时刻，若不同则记相反的边沿信号为标记时刻

库函数功能:

  • QEP_setLatchMode() 设置锁存模式

  • QEP_getCaptureTimerLatch() / QEP_getCapturePeriodLatch() / QEP_getIndexPositionLatch() / QEP_getStrobePositionLatch() 获取对应事件的位置计数锁存值

软件配置流程

  1. 配置IOMUX 配置对应 QEP 引脚为 EQEP 模式

  1. 配置解码器 调用 EQEP_setDecoderConfig() 传入EQEPx和解码器配置参数

  2. 设置位置计数器的复位模式 调用 EQEP_setPositionCounterConfig() 相关参数

  3. 设置捕获的分频配置 调用 EQEP_setCaptureConfig() 传入相关参数

  4. 设置QMA模式 调用 EQEP_setQMAModuleMode() 相关参数

  5. 输入源选择 调用 EQEP_selectSource() 传入EQEPx和配置参数

  6. 设置输入级性 调用 EQEP_setInputPolarity() 相关参数

  7. 使能捕获 调用 EQEP_enableCapture() 传入EQEPx

  8. 使能模块 调用 EQEP_enableModule() 传入EQEPx

  1. 选择 T 法或 M 法进行测速

应用示例

API Reference

Header File

Functions

void EQEP_enableModule(EQEP_Type *EQEPx)

enable the eqep module

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

void EQEP_disableModule(EQEP_Type *EQEPx)

disable the eqep module

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

void EQEP_enableCapture(EQEP_Type *EQEPx)

Enables the eQEP module edge-capture unit.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

void EQEP_disableCapture(EQEP_Type *EQEPx)

disables the eQEP module edge-capture unit.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

void EQEP_enableUnitTimer(EQEP_Type *EQEPx, uint32_t period)

Enables the eQEP module unit timer.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • period – period is period value at which a unit time-out interrupt is set.

void EQEP_disableUnitTimer(EQEP_Type *EQEPx)

disables the eQEP module unit timer.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

void EQEP_loadUnitTimer(EQEP_Type *EQEPx, uint32_t period)

Loads the eQEP module unit timer period as number of SYSCLK cycles.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • period – period is period value at which a unit time-out interrupt is set.

void EQEP_setDecoderConfig(EQEP_Type *EQEPx, uint32_t config)

Configures eQEP module’s quadrature decoder unit.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

    • EQEP0

    • EQEP1

  • config – The config parameter provides the configuration of the decoder and is the logical OR of several values:

    • specify if both rising and falling edges should be counted or just rising edges, by the following options: EQEP_CONFIG_2X_RESOLUTION or EQEP_CONFIG_1X_RESOLUTION

    • specify if quadrature signals are being provided on QEPA and QEPB, if a direction signal and a clock are being provided, or if the direction should be hard-wired for a single direction with QEPA used for input, by the following options: EQEP_CONFIG_QUADRATURE, or EQEP_CONFIG_CLOCK_DIR, or EQEP_CONFIG_UP_COUNT or EQEP_CONFIG_DOWN_COUNT

    • specify if the signals provided on QEPA and QEPB should be swapped before being processed, by the following options: EQEP_CONFIG_NO_SWAP or EQEP_CONFIG_SWAP

    • specify if the gating of the index pulse should be enabled or disabled, by the following options: EQEP_CONFIG_IGATE_DISABLE or EQEP_CONFIG_IGATE_ENABLE

void EQEP_setPositionCounterConfig(EQEP_Type *EQEPx, EQEP_PositionResetMode mode, uint32_t maxPosition)

Configures eQEP module position counter unit.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

    • EQEP0

    • EQEP1

  • mode –

    • EQEP_POSITION_RESET_IDX

    • EQEP_POSITION_RESET_MAX_POS

    • EQEP_POSITION_RESET_1ST_IDX

    • EQEP_POSITION_RESET_UNIT_TIME_OUT

  • maxPosition – maxPosition is the maximum value of the position counter and is the value used to reset the position capture when moving in the reverse(negative) direction. range :0x0 ~ 0xFFFFFFFF

void EQEP_setCaptureConfig(EQEP_Type *EQEPx, EQEP_CAPCLKPrescaler capPrescaler, EQEP_UPEVNTPrescaler evntPrescaler)

Configures eQEP module edge-capture unit.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • capPrescaler – capPrescaler is the prescaler setting of the eQEP capture timer clk.

  • evntPrescaler – evntPrescaler is the prescaler setting of the unit position event frequency.

void EQEP_setQMAModuleMode(EQEP_Type *EQEPx, EQEP_QMAMode qmaMode)

Set the quadrature mode adapter (QMA) module mode.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • qmaMode –

void EQEP_setStrobeSource(EQEP_Type *EQEPx, EQEP_StrobeSource strobeSrc)

Set the strobe input source of the eQEP module.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • strobeSrc –

void EQEP_selectSource(EQEP_Type *EQEPx, EQEP_SourceSelect sourceConfig)

Selects the source for eQEPA/B/I signals.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • sourceConfig –

void EQEP_setInputPolarity(EQEP_Type *EQEPx, bool invertQEPA, bool invertQEPB, bool invertIndex, bool invertStrobe)

Sets the polarity of the eQEP module’s input signals.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • invertQEPA – is the flag to negate the QEPA input.

  • invertQEPB – is the flag to negate the QEPA input.

  • invertIndex – is the flag to negate the index input.

  • invertStrobe – is the flag to negate the strobe input.

void EQEP_setPosition(EQEP_Type *EQEPx, uint32_t position)

Sets the current encoder position.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • position – position is the new position for the encoder. range: 0x0 ~ 0xFFFFFFFF

void EQEP_setPositionInitMode(EQEP_Type *EQEPx, uint16_t initMode)

Configures the mode in which the position counter is initialized.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • initMode – The initMode parameter provides the mode as either EQEP_INIT_DO_NOTHING (no action configured) or one of the following strobe events, index events, or a logical OR of both a strobe event and an index event.

    • strobe events: specify which strobe event will initialize the position counter. EQEP_INIT_RISING_STROBE or EQEP_INIT_EDGE_DIR_STROBE

    • index events: specify which index event will initialize the position counter. EQEP_INIT_RISING_INDEX or EQEP_INIT_FALLING_INDEX

void EQEP_setSWPositionInit(EQEP_Type *EQEPx, bool initialize)

Sets the software initialization of the encoder position counter.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • initialize – initialize is a flag to specify if software initialization of the position counter is enabled.

void EQEP_setInitialPosition(EQEP_Type *EQEPx, uint32_t position)

Sets the init value for the encoder position counter.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • position – position is the value to be written to the position counter upon.initialization.

uint32_t EQEP_getPosition(EQEP_Type *EQEPx)

Gets the current encoder position.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

uint32_t The current position of the encoder.

uint16_t EQEP_getCapturePeriod(EQEP_Type *EQEPx)

Gets the encoder capture period.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

uint16_t The period count value between the last successive position events. range 0x0 ~ 0xFFFF

uint16_t EQEP_getCaptureTimer(EQEP_Type *EQEPx)

Gets the encoder capture timer value.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

uint16_t The capture timer value. range 0x0 ~ 0xFFFF

int16_t EQEP_getDirection(EQEP_Type *EQEPx)

Gets the current direction of rotation.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

int16_t

  • Return 1 if moving in the forward direction

  • return -1 if moving in the reverse direction

void EQEP_enableCompare(EQEP_Type *EQEPx)

Enables the eQEP module position-compare unit.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

void EQEP_disableCompare(EQEP_Type *EQEPx)

Disables the eQEP module position-compare unit.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

void EQEP_setCompareConfig(EQEP_Type *EQEPx, EQEP_CompareConfigParam config, uint32_t compareValue, uint16_t cycles)

Configures eQEP module position-compare unit.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • config –

  • compareValue – compareValue is the value to which the position count value is compared for a position-compare event. range:0x0 ~ 0xFFFFFFFF. actual value = compareValue + 1.

  • cycles – The cycles is used to select the width of the sync output pulse. The width of the resulting pulse will be cycles * 4 * the width of a SYSCLKOUT cycle. The maximum width is 4096 * 4 * SYSCLKOUT cycles.

void EQEP_setComparePulseWidth(EQEP_Type *EQEPx, uint16_t cycles)

Configures the position-compare unit’s sync output pulse width.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • cycles – cycles is the width of the pulse that can be generated on a position-compare event. It is in units of 4 SYSCLKOUT cycles. config range:1 ~ 4096; actual range: 1 * 4*SYSCLKOUT ~ 4096 * 4* SYSCLKOUT note: param cycles cannot write 0.

void EQEP_enableWatchdog(EQEP_Type *EQEPx, uint16_t period)

Enables the eQEP module watchdog timer.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • period – period is watchdog period value at which a time-out will occur if no quadrature-clock event is detected.

void EQEP_disableWatchdog(EQEP_Type *EQEPx)

disables the eQEP module watchdog timer.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

void EQEP_setWatchdogTimerValue(EQEP_Type *EQEPx, uint16_t value)

Sets the eQEP module watchdog timer value.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • value – value is the value to be written to the watchdog timer.

uint16_t EQEP_getWatchdogTimerValue(EQEP_Type *EQEPx)

Gets the eQEP module watchdog timer value.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

uint16_t Return the current watchdog timer value.

void EQEP_setLatchMode(EQEP_Type *EQEPx, uint32_t latchMode)

Configures the quadrature modes in which the position count can be latched.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • latchMode – This function configures the events on which the position count and several other registers can be latched. The latchMode parameter provides the mode as the logical OR of several values.

    • specify the event that latches the position counter. EQEP_LATCH_CNT_READ_BY_CPU or EQEP_LATCH_UNIT_TIME_OUT

    • specify which strobe event will latch the position counter into the strobe position latch register. EQEP_LATCH_RISING_INDEX or EQEP_LATCH_FALLING_INDEX or EQEP_LATCH_SW_INDEX_MARKER

    • specify which index event will latch the position counter into the index position latch register. EQEP_LATCH_RISING_STROBE or EQEP_LATCH_EDGE_DIR_STROBE

uint32_t EQEP_getIndexPositionLatch(EQEP_Type *EQEPx)

Gets the encoder position that was latched on an index event.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

uint32_t return The position count latched on an index event.

uint32_t EQEP_getStrobePositionLatch(EQEP_Type *EQEPx)

Gets the encoder position that was latched on a strobe event.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

uint32_t return The position count latched on a strobe event.

uint32_t EQEP_getPositionLatch(EQEP_Type *EQEPx)

Gets the encoder position that was latched on a unit time-out event.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

uint32_t return The position count latch register value.

uint16_t EQEP_getCaptureTimerLatch(EQEP_Type *EQEPx)

Gets the encoder capture timer latch.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

uint16_t return The edge-capture timer latch value.

uint16_t EQEP_getCapturePeriodLatch(EQEP_Type *EQEPx)

Gets the encoder capture period latch.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

uint16_t return The edge-capture period latch value.

void EQEP_enableInterrupt(EQEP_Type *EQEPx, uint16_t intFlags)

Enables eQEP module interrupt sources.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • intFlags – The intFlags parameter can be any of the following values OR or together: EQEP_INT_DIR_CHANGE - Quadrature direction change EQEP_INT_PHASE_ERROR - Quadrature phase error EQEP_INT_POS_CNT_ERROR - Position counter error EQEP_INT_STROBE_EVNT_LATCH - Strobe event latch EQEP_INT_INDEX_EVNT_LATCH - Index event latch EQEP_INT_POS_COMP_READY - Position-compare ready EQEP_INT_POS_COMP_MATCH - Position-compare match EQEP_INT_UNDERFLOW - Position counter underflow EQEP_INT_OVERFLOW - Position counter overflow EQEP_INT_WATCHDOG - Watchdog time-out EQEP_INT_UNIT_TIME_OUT - Unit time-out EQEP_INT_QMA_ERROR - QMA error

void EQEP_disableInterrupt(EQEP_Type *EQEPx, uint16_t intFlags)

Disables eQEP module interrupt sources.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • intFlags – The intFlags parameter can be any of the following values OR or together: EQEP_INT_DIR_CHANGE - Quadrature direction change EQEP_INT_PHASE_ERROR - Quadrature phase error EQEP_INT_POS_CNT_ERROR - Position counter error EQEP_INT_STROBE_EVNT_LATCH - Strobe event latch EQEP_INT_INDEX_EVNT_LATCH - Index event latch EQEP_INT_POS_COMP_READY - Position-compare ready EQEP_INT_POS_COMP_MATCH - Position-compare match EQEP_INT_UNDERFLOW - Position counter underflow EQEP_INT_OVERFLOW - Position counter overflow EQEP_INT_WATCHDOG - Watchdog time-out EQEP_INT_UNIT_TIME_OUT - Unit time-out EQEP_INT_QMA_ERROR - QMA error

void EQEP_enableInterruptMask(EQEP_Type *EQEPx, uint16_t intFlags)

Mask eQEP module interrupts.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1] pointer to QEP module instance, [EQP0~EQP1]

  • intFlags – The intFlags parameter can be any of the following values OR or together: EQEP_INT_DIR_CHANGE - Quadrature direction change EQEP_INT_PHASE_ERROR - Quadrature phase error EQEP_INT_POS_CNT_ERROR - Position counter error EQEP_INT_STROBE_EVNT_LATCH - Strobe event latch EQEP_INT_INDEX_EVNT_LATCH - Index event latch EQEP_INT_POS_COMP_READY - Position-compare ready EQEP_INT_POS_COMP_MATCH - Position-compare match EQEP_INT_UNDERFLOW - Position counter underflow EQEP_INT_OVERFLOW - Position counter overflow EQEP_INT_WATCHDOG - Watchdog time-out EQEP_INT_UNIT_TIME_OUT - Unit time-out EQEP_INT_QMA_ERROR - QMA error

void EQEP_disableInterruptMask(EQEP_Type *EQEPx, uint16_t intFlags)

Unmask eQEP module interrupts.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1] pointer to QEP module instance, [EQP0~EQP1]

  • intFlags – The intFlags parameter can be any of the following values OR or together: EQEP_INT_DIR_CHANGE - Quadrature direction change EQEP_INT_PHASE_ERROR - Quadrature phase error EQEP_INT_POS_CNT_ERROR - Position counter error EQEP_INT_STROBE_EVNT_LATCH - Strobe event latch EQEP_INT_INDEX_EVNT_LATCH - Index event latch EQEP_INT_POS_COMP_READY - Position-compare ready EQEP_INT_POS_COMP_MATCH - Position-compare match EQEP_INT_UNDERFLOW - Position counter underflow EQEP_INT_OVERFLOW - Position counter overflow EQEP_INT_WATCHDOG - Watchdog time-out EQEP_INT_UNIT_TIME_OUT - Unit time-out EQEP_INT_QMA_ERROR - QMA error

uint16_t EQEP_getInterruptStatus(EQEP_Type *EQEPx)

Gets the current interrupt status.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

uint16_t Returned, as a bit field of the following values: EQEP_INT_DIR_CHANGE - Quadrature direction change EQEP_INT_PHASE_ERROR - Quadrature phase error EQEP_INT_POS_CNT_ERROR - Position counter error EQEP_INT_STROBE_EVNT_LATCH - Strobe event latch EQEP_INT_INDEX_EVNT_LATCH - Index event latch EQEP_INT_POS_COMP_READY - Position-compare ready EQEP_INT_POS_COMP_MATCH - Position-compare match EQEP_INT_UNDERFLOW - Position counter underflow EQEP_INT_OVERFLOW - Position counter overflow EQEP_INT_WATCHDOG - Watchdog time-out EQEP_INT_UNIT_TIME_OUT - Unit time-out EQEP_INT_QMA_ERROR - QMA error

uint16_t EQEP_getInterruptRawStatus(EQEP_Type *EQEPx)

gets the interrupt raw status.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

uint16_t Returned, as a bit field of the following values: EQEP_INT_DIR_CHANGE - Quadrature direction change EQEP_INT_PHASE_ERROR - Quadrature phase error EQEP_INT_POS_CNT_ERROR - Position counter error EQEP_INT_STROBE_EVNT_LATCH - Strobe event latch EQEP_INT_INDEX_EVNT_LATCH - Index event latch EQEP_INT_POS_COMP_READY - Position-compare ready EQEP_INT_POS_COMP_MATCH - Position-compare match EQEP_INT_UNDERFLOW - Position counter underflow EQEP_INT_OVERFLOW - Position counter overflow EQEP_INT_WATCHDOG - Watchdog time-out EQEP_INT_UNIT_TIME_OUT - Unit time-out EQEP_INT_QMA_ERROR - QMA error

void EQEP_clearInterruptStatus(EQEP_Type *EQEPx, uint16_t intFlags)

Clears eQEP module interrupt sources.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • intFlags – The intFlags parameter can be any of the following values OR or together: EQEP_INT_DIR_CHANGE - Quadrature direction change EQEP_INT_PHASE_ERROR - Quadrature phase error EQEP_INT_POS_CNT_ERROR - Position counter error EQEP_INT_STROBE_EVNT_LATCH - Strobe event latch EQEP_INT_INDEX_EVNT_LATCH - Index event latch EQEP_INT_POS_COMP_READY - Position-compare ready EQEP_INT_POS_COMP_MATCH - Position-compare match EQEP_INT_UNDERFLOW - Position counter underflow EQEP_INT_OVERFLOW - Position counter overflow EQEP_INT_WATCHDOG - Watchdog time-out EQEP_INT_UNIT_TIME_OUT - Unit time-out EQEP_INT_QMA_ERROR - QMA error

void EQEP_forceInterrupt(EQEP_Type *EQEPx, uint16_t intFlags)

Forces eQEP module interrupts.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • intFlags – The intFlags parameter can be any of the following values OR or together: EQEP_INT_DIR_CHANGE - Quadrature direction change EQEP_INT_PHASE_ERROR - Quadrature phase error EQEP_INT_POS_CNT_ERROR - Position counter error EQEP_INT_STROBE_EVNT_LATCH - Strobe event latch EQEP_INT_INDEX_EVNT_LATCH - Index event latch EQEP_INT_POS_COMP_READY - Position-compare ready EQEP_INT_POS_COMP_MATCH - Position-compare match EQEP_INT_UNDERFLOW - Position counter underflow EQEP_INT_OVERFLOW - Position counter overflow EQEP_INT_WATCHDOG - Watchdog time-out EQEP_INT_UNIT_TIME_OUT - Unit time-out EQEP_INT_QMA_ERROR - QMA error

bool EQEP_getError(EQEP_Type *EQEPx)

Gets the encoder error indicator. It is an error for both of the signals of the quadrature input to change at the same time.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

bool

  • Return true if an error has occurred

  • Return false otherwise.

uint8_t EQEP_getStatus(EQEP_Type *EQEPx)

Get content of the eQEP module status register.

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

uint16_t The value it returns is an OR of the following values: EQEP_STS_POS_CNT_ERROR - Position counter error occurred EQEP_STS_1ST_IDX_FLAG - Set by the occurrence of the first index pulse EQEP_STS_CAP_DIR_ERROR - Direction change occurred between position capture events EQEP_STS_CAP_OVRFLW_ERROR - Overflow occurred in eQEP capture timer EQEP_STS_DIR_LATCH - If set, clockwise rotation occurred on last index event marker EQEP_STS_DIR_FLAG - If set, movement is clockwise rotation EQEP_STS_DIR_ON_1ST_IDX - If set, clockwise rotation (forward movement) occurred on the first index event EQEP_STS_UNIT_POS_EVNT - Unit position event detected

void EQEP_clearStatus(EQEP_Type *EQEPx, uint8_t statusFlags)

Clears selected fields of the eQEP module status register.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • statusFlags – This function clears the status register fields indicated by statusFlags. The statusFlags parameter is the logical OR of any of the following: EQEP_STS_1ST_IDX_FLAG - Set by the occurrence of the first index pulse EQEP_STS_CAP_DIR_ERROR - Direction change occurred between position capture events EQEP_STS_CAP_OVRFLW_ERROR - Overflow occurred in eQEP capture timer EQEP_STS_UNIT_POS_EVNT - Unit position event detected

void EQEP_enableFilter(EQEP_Type *EQEPx)

enbale eQEP input signal filter

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

* void

void EQEP_disableFilter(EQEP_Type *EQEPx)

disable eQEP input signal filter

参数:

EQEPx – pointer to QEP module instance, [EQP0~EQP1]

返回:

* void

void EQEP_setFilterRange(EQEP_Type *EQEPx, uint16_t len)

set eEQP output signal filter window range

参数:

  • EQEPx – pointer to eQEP module instance, [EQP0~EQP1]

  • len –

返回:

* void

void EQEP_setEmulationMode(EQEP_Type *EQEPx, EQEP_EmulationMode emuMode)

Set the emulation mode of the eQEP module.

参数:

  • EQEPx – pointer to QEP module instance, [EQP0~EQP1]

  • emuMode –

Structures

struct EQEP_SourceSelect
struct EQEP_CompareConfigParam

Macros

EQEP_CONFIG_QUADRATURE
EQEP_CONFIG_CLOCK_DIR
EQEP_CONFIG_UP_COUNT
EQEP_CONFIG_DOWN_COUNT
EQEP_CONFIG_2X_RESOLUTION
EQEP_CONFIG_1X_RESOLUTION
EQEP_CONFIG_NO_SWAP
EQEP_CONFIG_SWAP
EQEP_CONFIG_IGATE_DISABLE
EQEP_CONFIG_IGATE_ENABLE
EQEP_INT_DIR_CHANGE
EQEP_INT_PHASE_ERROR
EQEP_INT_POS_CNT_ERROR
EQEP_INT_STROBE_EVNT_LATCH
EQEP_INT_INDEX_EVNT_LATCH
EQEP_INT_POS_COMP_READY
EQEP_INT_POS_COMP_MATCH
EQEP_INT_UNDERFLOW
EQEP_INT_OVERFLOW
EQEP_INT_WATCHDOG
EQEP_INT_UNIT_TIME_OUT
EQEP_INT_QMA_ERROR
EQEP_STS_POS_CNT_ERROR
EQEP_STS_1ST_IDX_FLAG
EQEP_STS_CAP_DIR_ERROR
EQEP_STS_CAP_OVRFLW_ERROR
EQEP_STS_DIR_LATCH
EQEP_STS_DIR_FLAG
EQEP_STS_DIR_ON_1ST_IDX
EQEP_STS_UNIT_POS_EVNT
EQEP_INIT_DO_NOTHING
EQEP_INIT_RISING_STROBE
EQEP_INIT_EDGE_DIR_STROBE
EQEP_INIT_RISING_INDEX
EQEP_INIT_FALLING_INDEX
EQEP_LATCH_CNT_READ_BY_CPU
EQEP_LATCH_UNIT_TIME_OUT
EQEP_LATCH_RISING_INDEX
EQEP_LATCH_FALLING_INDEX
EQEP_LATCH_SW_INDEX_MARKER
EQEP_LATCH_RISING_STROBE
EQEP_LATCH_EDGE_DIR_STROBE

Enumerations

enum EQEP_CompareSyncOut

Values:

enumerator EQEP_COMPARE_IDX_SYNC_OUT
enumerator EQEP_COMPARE_STROBE_SYNC_OUT
enum EQEP_Compare_ShadowSigSel

Values:

enumerator EQEP_COMPARE_LOAD_ON_ZERO
enumerator EQEP_COMPARE_LOAD_ON_MATCH
enum EQEP_PositionResetMode

Values:

enumerator EQEP_POSITION_RESET_IDX
enumerator EQEP_POSITION_RESET_MAX_POS
enumerator EQEP_POSITION_RESET_1ST_IDX
enumerator EQEP_POSITION_RESET_UNIT_TIME_OUT
enum EQEP_CAPCLKPrescaler

Values:

enumerator EQEP_CAPTURE_CLK_DIV_1
enumerator EQEP_CAPTURE_CLK_DIV_2
enumerator EQEP_CAPTURE_CLK_DIV_4
enumerator EQEP_CAPTURE_CLK_DIV_8
enumerator EQEP_CAPTURE_CLK_DIV_16
enumerator EQEP_CAPTURE_CLK_DIV_32
enumerator EQEP_CAPTURE_CLK_DIV_64
enumerator EQEP_CAPTURE_CLK_DIV_128
enum EQEP_UPEVNTPrescaler

Values:

enumerator EQEP_UNIT_POS_EVNT_DIV_1
enumerator EQEP_UNIT_POS_EVNT_DIV_2
enumerator EQEP_UNIT_POS_EVNT_DIV_4
enumerator EQEP_UNIT_POS_EVNT_DIV_8
enumerator EQEP_UNIT_POS_EVNT_DIV_16
enumerator EQEP_UNIT_POS_EVNT_DIV_32
enumerator EQEP_UNIT_POS_EVNT_DIV_64
enumerator EQEP_UNIT_POS_EVNT_DIV_128
enumerator EQEP_UNIT_POS_EVNT_DIV_256
enumerator EQEP_UNIT_POS_EVNT_DIV_512
enumerator EQEP_UNIT_POS_EVNT_DIV_1024
enumerator EQEP_UNIT_POS_EVNT_DIV_2048
enum EQEP_QMAMode

Values:

enumerator EQEP_QMA_MODE_BYPASS
enumerator EQEP_QMA_MODE_1
enumerator EQEP_QMA_MODE_2
enum EQEP_Source

Values:

enumerator EQEP_SOURCE_DEVICE_PIN
enumerator EQEP_SOURCE_ACMP0B
enumerator EQEP_SOURCE_ACMP1B
enumerator EQEP_SOURCE_ACMP2B
enumerator EQEP_SOURCE_ACMP3B
enumerator EQEP_SOURCE_ACMP0A
enumerator EQEP_SOURCE_ACMP1A
enumerator EQEP_SOURCE_ACMP2A
enumerator EQEP_SOURCE_ACMP3A
enumerator EQEP_SOURCE_XBAR_GRP0_PFXB0
enumerator EQEP_SOURCE_XBAR_GRP0_PFXB1
enumerator EQEP_SOURCE_XBAR_GRP0_PFXB2
enumerator EQEP_SOURCE_XBAR_GRP0_PFXB3
enumerator EQEP_SOURCE_XBAR_GRP0_PFXB4
enumerator EQEP_SOURCE_XBAR_GRP0_PFXB5
enumerator EQEP_SOURCE_XBAR_GRP1_PFXB0
enum EQEP_EmulationMode

Values:

enumerator EQEP_EMULATIONMODE_STOPIMMEDIATELY
enumerator EQEP_EMULATIONMODE_STOPATROLLOVER
enumerator EQEP_EMULATIONMODE_RUNFREE
enum EQEP_StrobeSource

Values:

enumerator EQEP_STROBE_FROM_GPIO
enumerator EQEP_STROBE_OR_ADCSOCA
enumerator EQEP_STROBE_OR_ADCSOCB