interrupt handling

Hello There,

using below peace of code i am trying to read external 8 bit data from DATA_IN bus.during edge_capture interrupt arrive, though it read almost all data but it miss 2-3 data during reading.

LPKtCount = 178

PktSize = 1472

if(edge_capture)

{

edge_capture = 0; //reset interrupt

imgbuff[lpktcount][count++] = iord_altera_avalon_pio_data(data_in_base);

if(count == pktsize) //check end of packet-data -->1472

{

count = 0; //point to start of packet data

lpktcount++; //increment packet count

}

}

//-------------------------------------------------------------------------

ImgBuff[MaxPacket][PktSize] is a two dimentional array which hold the Incomind data (8 bit). Writing data in Array only during Edge_capture Interrupt arrive (LOAD).

Every time edge_capture interrupt get high it load the data from external sybc_detct and write in to two dimentional array. But some time it misse the data and read next data.

(for sake simplicity i have give count sequence as a input data)

As shown in print screen of output highlighted part, where 39 is the Address and 40 is the data. This position 39:40 is not a fix position next time it miss some different value.

Address is locally generated counter but reading data from external sync_detect (from 8 bit bus).

7. I have seen (On Logic Analyzer) that external sync _detect gives proper data mean it is not missing any data. Please suggest Guide where went wrong in my code.

I have assign highest priority to this load pulse.

Please see PrintScreen of

1. Hardware (Nios-II and Sync_Detect)

2. Software Output (Highleted)

regards

kaushal kanwariya