TMS570LS3137: recieving 2 bytes of data through spi and transmit 1 byte of data through CAN

 i am a beginner , having some doubt.. my task is to recieve 100 bytes of data through spi and transmit the same through can.

by studying the TRM of TMS570LS3137, i understood at max 2 bytes of data can be recieved through spi function mibspiGetData(). and through can 1 byte of data can be transferred through canTransmit() function.

My questions are:

1. I studied CAN can transmit 0-8 bytes of data, but canTransmit() function is limiting it to 1 byte , why so ?

2. also i am facing problem in accessing 1 byte data (for can transmit ) from 2byte data stored in buffer after spi . Please help me with this

my code:

/* USER CODE BEGIN (0) */
/* USER CODE END */

/* Include Files */

#include "sys_common.h"
#include "mibspi.h"
#include "can.h"

/* USER CODE BEGIN (1) */
int data;
int *pdata;
uint16 rxbuffer[];
uint8 RB[];
uint8 buff;

/* USER CODE END */

/** @fn void main(void)
* @brief Application main function
* @note This function is empty by default.
*
* This function is called after startup.
* The user can use this function to implement the application.
*/

/* USER CODE BEGIN (2) */
/* USER CODE END */

int main(void)
{
/* USER CODE BEGIN (3) */
mibspiInit();
canInit();

int i,j;

for(i=0;i<10;i++)
{
for(j=0;j<5;j++)
{
rxbuffer[]= *(pdata);
pdata++;

mibspiGetData(mibspiREG1,0,rxbuffer);

}

/*stuck over here...*/

/* USER CODE END */
return 0 ;
}