en:netzer:io

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en:netzer:io [2014/07/22 17:52] – [Impulse output] sveschen:netzer:io [2025/06/11 20:42] (current) – external edit 127.0.0.1
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-===== Pulse trigger =====+===== Pulse trigger (IO0) =====
  
-Apart from the normal digital function, IO0 can also activate interrupts. On the interrupt, an [[io#edgecounter|edge counter]] is installed. Moreover, an edge may be used at this pin to initiate pulses at **IO3** or **SPI_INT**.+The IO0 channel has installed some more interrupt handling than IO1 and IO2. 
 +Apart from the normal digital function and the [[io#edgecounter|edge counter]] functionality IO0 can handle the following features:
  
-For the activation of the edge, the I00 edge trigger **must** **be activated**. Depending on the setting, the pulse is activated in the event of negative or positive edges. The edge counter, however, must not be necessarily active for pulse activation. For external trigger signals, IO0 must be configured as a digital input. +  * Reload the impulse timer which is used for capture and impulse generation on IO3 and SPI_INT 
 +  * Initiate pulse on IO3 and SPI_INT. 
 + 
 +{{ io0config.gif?direct | }} 
 + 
 +The impulse timer is the core part for generating and measuring impulses on IO3 and SPI_INT.  
 +If the reset check is marked the dedicated impulse timer is reset when the IO0 interrupt occurs.  
 + 
 +For the activation of the interrupt handler, the I00 edge trigger **must** **be activated**.  
 + 
 +Depending on the setting, the pulse is activated in the event of negative or positive edges. The edge counter, however, must not be necessarily active for pulse activation. For external trigger signals, IO0 must be configured as a digital input. 
  
  
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   * Impulse mode   * Impulse mode
   * Impulse unit   * Impulse unit
 +  * Calibration offset
 </note> </note>
  
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 <WRAP center round important 60%> <WRAP center round important 60%>
-**The PWM mode uses an independent timer.**+**The PWM mode uses an independent timer (NOT the impulse timer).**
 It is shared between IO3 and SPI_INT if both are configured for PWM only.  It is shared between IO3 and SPI_INT if both are configured for PWM only. 
 Those the PWM frequency is set for both IO3 and SPI_INT if configured as PWM. Those the PWM frequency is set for both IO3 and SPI_INT if configured as PWM.
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 In impulse mode, individual or also continuous pulse sequencies may be generated.  In impulse mode, individual or also continuous pulse sequencies may be generated. 
  
-The pulse value is 16\ bit in width, but has a **minimum value of 100**, which cannot be fallen below. The value itself is written or read via the GPIO main page or via the [[gpioserver|GPIO server]] or [[commandinterface|command interface]]. The pulse length is internally buffered so that the output signal does not accept any inadmissible states in the event of amendments. +The pulse value is 16\ bit in width. The value itself is written or read via the GPIO main page or via the [[gpioserver|GPIO server]] or [[commandinterface|command interface]]. The pulse length is internally buffered so that the output signal does not accept any inadmissible states in the event of amendments. 
  
 The logic refers to the polarity of the pulse. 0-Logic means the pulse is 0, the pin accepts the 1-state. 1-logic means the pulse is 1, the pin accepts 0-state. The logic refers to the polarity of the pulse. 0-Logic means the pulse is 0, the pin accepts the 1-state. 1-logic means the pulse is 1, the pin accepts 0-state.
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 Analogous to PWM a pulsed current is generated at the pin. It is always triggered whenever an internal counter flows over. The time duration of the counter is (65556*pulse unit). For IO3 and SPI_INT the same internal counter is used, so that both signals are always in phase. Analogous to PWM a pulsed current is generated at the pin. It is always triggered whenever an internal counter flows over. The time duration of the counter is (65556*pulse unit). For IO3 and SPI_INT the same internal counter is used, so that both signals are always in phase.
  
 +
 +Read more on the [[impulse|impulse page]].
  
 ==== Input capture (since version 1.6) ==== ==== Input capture (since version 1.6) ====
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 The capture (second) edge can be configured as falling or rising one. The capture (second) edge can be configured as falling or rising one.
 The trigger edge depends on the common impulse mode parameter (see below). The trigger edge depends on the common impulse mode parameter (see below).
- 
-The calibration offset shall be used to compensate interrupt latency time and clock errors. 
-The value is added to each measured value automatically. 
  
 On Netzer startup or after configuring for capture mode the measured value is set to 0. On Netzer startup or after configuring for capture mode the measured value is set to 0.
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 The measured value must be multiplied with the set time unit to get the final measured time. The measured value must be multiplied with the set time unit to get the final measured time.
 +
 +The measured value is 0xFFFF if the timer has overflown before the capture edge has occured.
 +
  
 //Mode single current pulse// //Mode single current pulse//
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 If trigger edge is rising and capture edge is falling the highimpulse width of a signal can be measured. If trigger edge is rising and capture edge is falling the highimpulse width of a signal can be measured.
  
 +Read more on the [[impulse|impulse page]].