哪位高手给讲讲定时器？

我现在用的是5502的板子，在板上UARTONCHIP测试程序中，GPT_Config MyGptConfig {0,0,0,0,0,0x56c4,0x0003,0...}函数中的0x56c4,0x0003是怎样计算出来的?能不能把具体的计算过程告诉我?我对这个问题已经困惑很久了，查了很多的资料始终也没弄明白，知道的朋友们给我讲讲吧，谢谢了！！呜呜

#include <stdio.h>
#include <csl.h>
#include <csl_chip.h>
#include <csl_irq.h>
#include <csl_gpt.h>
#include <csl_uart.h>
#include \"Uart_Function.h\"

/* Reference start of interrupt vector table */
/* This symbol is defined in file, vectors.s55 */
extern void VECSTART(void);

/* Function/ISR prototypes */
interrupt void Timer0Isr(void);

/* Create a TIMER_Handle object for use with TIMER_open */
GPT_Handle hGpt;
Uint16 Counter;
Uint16 EventId0; // 定时器0所对应的事件ID号

/****************************************************************/
/* Define and initialize the GPT module configuration structure */
/* Input fast peripheral clock is 100MHz */
/* Generate character interval interrupt Note:1etu=1/9600秒 */
/*--------------------------------------------------------------*/
/* 10etu 0x19708 1.042ms */
/* 12etu 0x1E870 1.250ms */
/* 14etu 0x239D8 1.459ms */
/* 20etu 0x32E10 2.084ms */
/* 40etu 0x65C20 4.168ms */
/****************************************************************/
GPT_Config MyGptConfig = {
0, //Emulation management register
0, //GPIO interrupt control register
0, //GPIO enable register
0, //GPIO direction register
0, //GPIO data register
//0x39D8, //Timer period register 1(主频为200MHz)
//0x0002, //Timer period register 2
0x56C4, //Timer period register 1(主频为300MHz)
0x0003, //Timer period register 2
0, //Timer period register 3
0，
GPT_GPTCTL1_RMK( //Timer control register 1
GPT_GPTCTL1_TIEN_NOT_GATED,
GPT_GPTCTL1_CLKSRC_VBUS,
GPT_GPTCTL1_ENAMODE_CONTINUOUS,
GPT_GPTCTL1_PWID_INACTIVE_1CYCLE,
GPT_GPTCTL1_CP_CLOCK_MODE,
GPT_GPTCTL1_INVIN_DONT_INVERT_OUTPUT,
GPT_GPTCTL1_INVOUT_DONT_INVERT_OUTPUT
,
GPT_GPTCTL2_RMK( //Timer control register 2
GPT_GPTCTL2_TIEN_NOT_GATED,
GPT_GPTCTL2_CLKSRC_VBUS,
GPT_GPTCTL2_ENAMODE_CONTINUOUS,
GPT_GPTCTL2_PWID_INACTIVE_1CYCLE,
GPT_GPTCTL2_CP_CLOCK_MODE,
GPT_GPTCTL2_INVIN_DONT_INVERT_OUTPUT,
GPT_GPTCTL2_INVOUT_DONT_INVERT_OUTPUT
,
GPT_GPTGCTL1_RMK( //Global timer control register
GPT_GPTGCTL1_PSC34_DEFAULT,
GPT_GPTGCTL1_TIMMODE_DEFAULT,
GPT_GPTGCTL1_TIM34RS_IN_RESET,
GPT_GPTGCTL1_TIM12RS_IN_RESET

};

在帮助里面找C55x Chip Support Library中的GPT Module，里面有GPT_Config的结构说明：
Structure

GPT_Config

Members

Uint16 gptemu //Emulation management register
Uint16 gptgpint //GPIO interrupt control register
Uint16 gptgpen //GPIO enable register
Uint16 gptgpdir //GPIO direction register
Uint16 gptgpdat //GPIO data register
Uint16 gptprd1 //Timer period register 1
Uint16 gptprd2 //Timer period register 2
Uint16 gptprd3 //Timer period register 3
Uint16 gptprd4 //Timer period register 4
Uint16 gptctl1 //Timer control register 1
Uint16 gptctl2 //Timer control register 2

Uint16 gptgctl1 //Global timer control register

Description

This is the GPT configuration structure used to configure a GPT device. The user should create and initalize this structure before passing its address to the GPT_config function.

看这个结构，都是寄存器的设置，因此如果你要找相应的寄存器的说明的话，就要找相应的文档：
TMS320VC5501/5502 DSP Timers Reference Guide。