• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 198 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TCAN1145-Q1: SDO pin use as an interrupt pin

smita wadekar
Prodigy 50 points
Part Number: TCAN1145-Q1

When i will configure SDO pin to be used as an interrupt pin also, will i be able to get the interrupt on that pin only when transceiver wakes up using Wakeup frame.

Actually when transceiver will be in sleep mode and wakes up using selective wakeup mechanism then is there any mechanism which notifies the state transition from sleep to standby instead of checking the MODE_CNTRL register value?

Please let me know. Thank you.

  • +1
    TI__Guru 53575 points

    Hi Smita,

    Thanks for sharing your question on E2E. 

    The main method for detecting the transceiver's transition from sleep mode to standby mode is that the battery-level output pin INH will turn on.This is typically used to enable a voltage regulator that powers the rest of the system.This allows for the MCU to be completely powered off while the transceiver is in sleep mode waiting for the proper wake up frame. 

    If the MCU is to remain active while the transceiver is in sleep mode, there are other IO-voltage signals that can be used to indicate that a wake event has occurred. This includes the RXD pin which will latch low when a wake up request is received (see datasheet section 10.4.4.1) and the nINT function of the SDO pin which will assert low whenever any of the enabled interrupts (which can include CANINT for bus wake conditions) are set. Note that all IO-level signals will require that Vio is present on the supply for TCAN1145. 

    Let me know if this is clear and if you have any more questions. 

    Regards, 
    Eric Schott 

  • 0 in reply to Eric Schott1
    Prodigy 50 points

    Thank you so much for detailed information about detecting the transit to standby scenario.

  • 0 in reply to Eric Schott1
    Prodigy 50 points

    Hi Eric,

    I have TCAN1145 tranceiver IC connected to AURIX TC364 controller.

    I wanted to know one thing that after selective wakeup using wakeup frame when transceiver transit to standby state, how AURIX controller will get to know about this state transition (i.e. wakeup has occured) via interrupt. 

    When i put transceiver in sleep state, i observed that it sets the CANSLNT bit of INT_1 register. So even if i configure SDO pin as an interrupt pin, i will get the interrupt on this pin in sleep state also due to setting of CANSLNT bit so this mechanism is not useful for me for wakeup detection. Is my understanding correct?

    If yes then please suggest how AURIX controller can get an idea about sleep to standby transition after wakeup without checking MODE_CTRL register.

  • 0 in reply to smita wadekar
    TI__Guru 53575 points

    Hi Smita,

    The nINT pin only asserts when enabled interrupts are set. Interrupts can be enabled or disabled using their corresponding interrupt enable registers (55h-59h). This can be used to disable the CANSLT interrupt so that it won't have any impact on the nINT pin status. 

    If Vio is present, the RXD pin will also assert when the transceiver wakes from sleep mode into standby mode.This is the primary method of wake recognition used in many systems where the MCU remains active in sleep mode. For systems where the INH signal enables the MCU power, it is possible to completely unpower the MCU while the transceiver is in sleep mode. When the transceiver wakes into standby mode, the INH pin will go high to enable power to the MCU causing a POR event that the MCU can recognise as a wake condition. 

    Regards, 
    Eric Schott