topic Re: CRC failed on 802.15.4 MAC/PHY ??? in 8-bit Microcontrollers https://community.nxp.com/t5/8-bit-Microcontrollers/CRC-failed-on-802-15-4-MAC-PHY/m-p/130664#M2539 <HTML><HEAD></HEAD><BODY>But how could the packet get corrupted after the MAC sends it to the app using an MCPS_Data.indication? The MAC uses a memory pool from which it allocates its messages dynamically. Only my packet handling function should be accessing its memory until I free it, unless of course the memory management (Freescale code) has a problem???<BR /><BR />Thanks<BR />Marc</BODY></HTML> Fri, 31 Mar 2006 06:41:47 GMT Marc 2006-03-31T06:41:47Z CRC failed on 802.15.4 MAC/PHY ??? https://community.nxp.com/t5/8-bit-Microcontrollers/CRC-failed-on-802-15-4-MAC-PHY/m-p/130662#M2537 <HTML><HEAD></HEAD><BODY><SPAN>Hi,</SPAN><BR /><BR /><SPAN>We've modified the EVK Switch demo to be sending direct data packets at full speed from a coordinator to an FFD device (RX on when idle). We only send one 102 byte packet at a time, waiting for a positive or negative acknoledgement before re-sending. This sends approximately 120 packets per second.</SPAN><BR /><BR /><SPAN>We're sending dummy data but we've added our own little simple 8 bit checksum inside the data packet. At reception on the device, we verify the checksum and enter a dead loop if it fails.</SPAN><BR /><BR /><SPAN>We've notice that the program will enter the dead loop after some varying amount of time (from 15 min, to a couple of hours). This would indicate that the received data was incorrect, but that the CRC of the MAC/PHY still accepted it.</SPAN><BR /><BR /><SPAN>Is this possible? Any ideas?</SPAN><BR /><BR /><SPAN>Marc</SPAN></BODY></HTML> Fri, 31 Mar 2006 04:24:05 GMT https://community.nxp.com/t5/8-bit-Microcontrollers/CRC-failed-on-802-15-4-MAC-PHY/m-p/130662#M2537 Marc 2006-03-31T04:24:05Z Re: CRC failed on 802.15.4 MAC/PHY ??? https://community.nxp.com/t5/8-bit-Microcontrollers/CRC-failed-on-802-15-4-MAC-PHY/m-p/130663#M2538 <HTML><HEAD></HEAD><BODY>HI Marc:<BR /><BR />The first thing that occurs to me is that your packet gets corrupted in the middle of the process (after being received, but before finishing the checksum check).<BR /><BR />Maybe another interrupt is causing this, or a second packet overwriting the first packet, or a NULL packet?<BR /><BR />Regards,<BR /><BR />Alex</BODY></HTML> Fri, 31 Mar 2006 06:20:54 GMT https://community.nxp.com/t5/8-bit-Microcontrollers/CRC-failed-on-802-15-4-MAC-PHY/m-p/130663#M2538 alex_spotw 2006-03-31T06:20:54Z Re: CRC failed on 802.15.4 MAC/PHY ??? https://community.nxp.com/t5/8-bit-Microcontrollers/CRC-failed-on-802-15-4-MAC-PHY/m-p/130664#M2539 <HTML><HEAD></HEAD><BODY>But how could the packet get corrupted after the MAC sends it to the app using an MCPS_Data.indication? The MAC uses a memory pool from which it allocates its messages dynamically. Only my packet handling function should be accessing its memory until I free it, unless of course the memory management (Freescale code) has a problem???<BR /><BR />Thanks<BR />Marc</BODY></HTML> Fri, 31 Mar 2006 06:41:47 GMT https://community.nxp.com/t5/8-bit-Microcontrollers/CRC-failed-on-802-15-4-MAC-PHY/m-p/130664#M2539 Marc 2006-03-31T06:41:47Z Re: CRC failed on 802.15.4 MAC/PHY ??? https://community.nxp.com/t5/8-bit-Microcontrollers/CRC-failed-on-802-15-4-MAC-PHY/m-p/130665#M2540 <HTML><HEAD></HEAD><BODY>HI:<BR /><BR />I haven't use the MAC code, but the SMAC that did have questionable programming techniques, like reeentrant interrupts for changing modes (from Idle to TX, to RX, etc).<BR /><BR />You might want to code review the MCS code to try to find memory leaks.<BR /><BR />Regards,<BR /><BR />Alex</BODY></HTML> Fri, 31 Mar 2006 22:37:36 GMT https://community.nxp.com/t5/8-bit-Microcontrollers/CRC-failed-on-802-15-4-MAC-PHY/m-p/130665#M2540 alex_spotw 2006-03-31T22:37:36Z Re: CRC failed on 802.15.4 MAC/PHY ??? https://community.nxp.com/t5/8-bit-Microcontrollers/CRC-failed-on-802-15-4-MAC-PHY/m-p/130666#M2541 <HTML><HEAD></HEAD><BODY>Do you have any suggestions as to what to look for?<BR /><BR />Thanks<BR />Marc</BODY></HTML> Wed, 05 Apr 2006 03:06:47 GMT https://community.nxp.com/t5/8-bit-Microcontrollers/CRC-failed-on-802-15-4-MAC-PHY/m-p/130666#M2541 Marc 2006-04-05T03:06:47Z