interrupt_ethernet

#include <net_config.h>

void interrupt_ethernet (void) __irq

The interrupt_ethernet function is the ethernet controller interrupt request function that gets called immediately when the ethernet controller receives a new frame. The function first allocates a block of memory. It then reads and copies the packet from the ethernet controller into the allocated memory. The function puts the memory block pointer into the received frames queue by calling the put_in_queue function.

The interrupt_ethernet function is part of RL-TCPnet. The prototype is defined in net_config.h.

note

• You must provide the interrupt_ethernet function if the ethernet controller you use is different from the ones provided in the TCPnet source.
• You must provide the interrupt_ethernet function only if you want to use the ethernet controller in interrupt mode.
• When you call alloc_mem to allocate the block of memory, ensure that the most significant bit in its argument size is set to 1. This is to prevent system hang error when it is out of memory.

The interrupt_ethernet function does not return any value.

init_ethernet, send_frame

static void interrupt_ethernet (void) __irq {
  /* EMAC Ethernet Controller Interrupt function. */
  OS_FRAME *frame;
  U32 idx,int_stat,RxLen,info;
  U32 *sp,*dp;

  while ((int_stat = (MAC_INTSTATUS & MAC_INTENABLE)) != 0) {
    MAC_INTCLEAR = int_stat;
    if (int_stat & INT_RX_DONE) {
      /* Packet received, check if packet is valid. */
      idx = MAC_RXCONSUMEINDEX;
      while (idx != MAC_RXPRODUCEINDEX) {
        info = Rx_Stat[idx].Info;
        if (!(info & RINFO_LAST_FLAG)) {
          goto rel;
        }

        RxLen = (info & RINFO_SIZE) - 3;
        if (RxLen > ETH_MTU || (info & RINFO_ERR_MASK)) {
          /* Invalid frame, ignore it and free buffer. */
          goto rel;
        }
        /* Flag 0x80000000 to skip sys_error() call when out of memory. */
        frame = alloc_mem (RxLen | 0x80000000);
        /* if 'alloc_mem()' has failed, ignore this packet. */
        if (frame != NULL) {
          dp = (U32 *)&frame->data[0];
          sp = (U32 *)Rx_Desc[idx].Packet;
          for (RxLen = (RxLen + 3) >> 2; RxLen; RxLen--) {
            *dp++ = *sp++;
          }
          put_in_queue (frame);
        }
rel:    if (++idx == NUM_RX_FRAG) idx = 0;
        /* Release frame from EMAC buffer. */
        MAC_RXCONSUMEINDEX = idx;
      }
    }
    if (int_stat & INT_TX_DONE) {
      /* Frame transmit completed. */
    }
  }
  /* Acknowledge the interrupt. */
  VICVectAddr = 0;
}