In addition to increasing the frame length (frm_length register = 9600) as stated in Triple Speed Ethernet User Guide, the following parameters found in the file triple_speed_ethernet_iniche.h must be modified as shown in order to enable the TSE MAC driver to handle Jumbo packets.
/* System Constant Definition Used in the TSE Driver Code */
#define ALTERA_TSE_PKT_INIT_LEN 1528
#define ALTERA_TSE_ADMIN_STATUS_DOWN 2
#define ALTERA_TSE_ADMIN_STATUS_UP 1
#define ALTERA_TSE_MAX_MTU_SIZE 1514
#define ALTERA_TSE_MIN_MTU_SIZE 14
#define ALTERA_TSE_HAL_ADDR_LEN 6
triple_speed_ethernet_iniche.h is located at the following installation directory:- <altera_installation>\ip\altera\triple_speed_ethernet\lib\sopc_builder\altera_triple_speed_ethernet\UCOSII\inc\iniche\triple_speed_ethernet_iniche.h