Dp83848+ network cable hot plug

Process description

 

1 Power failure and interruption

         The power down and interrupt functions are in the 7 Foot reuse . By default , This pin As power-off input , The interrupt function is disabled . Set up MICR position 0 (INT_OE)(0x11h) Configure the pin as an active low-level interrupt output .

2 Power down control mode

        PWRDOWN_INT The pin can be asserted as low to place the device in Power Down Pattern . This is equivalent to the basic mode control register BMCR (0x00h) Set the 11 position ( Power on ). An external control signal is used to drive the pin low , It overcomes the disadvantage of weak internal pull-up resistance . in addition , By using an external pull-down resistor , The device can be configured to initialize to Power Down State in PWRDOWN_INT On the pin . Because the device will still respond to the access of the management register , Set up MICR In the register INT_OE Bit will be disabled PWRDOWN_INT Input , Allow the device to exit the power-off state .

3 Interrupt mechanism

         The interrupt function is controlled by register access . By default , All interrupt sources are disabled . take MICR（0x11h） Bit 1（INTEN） Set up 1 Will make the interrupt output , It depends on MISR（0x12h） Interrupt mask set in the low byte of . When an interrupt condition occurs ,PWRDOWN_INT Pin asynchronously set to low level . Can be read through MISR To determine the interrupt source . MISR One or more of them will be set to 1, Indicates all currently pending interrupts . Read MISR Will clear all pending interrupts .

Example ： To generate an interrupt when the link state changes or the energy detection power state changes , Steps are as follows ：
• take 0003h write in MICR Set up INTEN and INT_OE
• towards MISR write in 0060h Set up ED_INT_EN and LINK_INT_EN
• monitor PWRDOWN_INT Pin
         When PWRDOWN_INT Pin for low level , The user will read MISR Register to see ED_INT or LINK_INT Location 1, for example , The source of the interrupt . Read MISR after , Interrupt reset ,PWRDOWN_INT Pin will be set to invalid .

  register

  

 

Code instructions

1. DP83848 Of 7 foot INT Access MCU Of IO mouth ,IO Configured as an external interrupt ,

2. Set up MICR（0x11） Of INTEN and INT_OE Position as 1,

3. Set up MISR（0x12） Of ED_INT_EN and LINK_INT_EN Position as 1,

4. View in external interrupt MISR（0x12） in ED_INT and LINK_INT Whether the bit is set 1,

5. if ED_INT and LINK_INT position by 1, Further view BMSR（0x01） Of LINK STATUS and AUTO-NEGOTIATION Whether a is 1, if 1 It means that the network cable has been inserted , Initialize the network and create tcp link ; If not 1 It means that the network cable has been unplugged , close tcp link .