Port for AT89C51ED2

Hi all. I am trying to do a port for Atmel AT89C51ED2 (type 8052 as Cygnal) derived from port for Cygnal. AT89C51ED2 have 1792 bytes of XRAM. I have only three tasks, idle ,vErrorChecks and my test task. When the perogram try to do first time xTaskCreate it does not succeed to allocate memory (pvPortMalloc=NULL). I have #define configMINIMAL_STACK_SIZE    ( ( unsigned portSHORT ) 200 – ( unsigned portSHORT ) configSTACK_START ) #define configTOTAL_HEAP_SIZE        ( ( size_t ) ( 1 * 896 ) ) Is XRAM of AT89C51ED2 sufficient for this port or the problem is elsewhere?