option.s

来自「杭州立宇泰ARMsys－P型ARM开发板BIOS代码」· S 代码 · 共 34 行

;汇编程序设置  2005.5.17 

;**********OPTIONS*******************************
;_RAM_STARTADDRESS  EQU   0xc000000
_ISR_STARTADDRESS   EQU   0xc7ff000	;GCS6:8MB SDRAM
_IRQ_BASEADDRESS   EQU   0xc000000 	;GCS6:8MB SDRAM

;16位或者32位总线设置 BUSWIDTH; 16,32
                GBLA    BUSWIDTH
BUSWIDTH	SETA    16

;"DRAM"OR"SDRAM"
                GBLS    BDRAMTYPE
BDRAMTYPE	SETS    "SDRAM"

;这个值在Flash存储器编程时应该为真 his value has to be TRUE on ROM program.
;这个值在SDRAM存储器编程时应该为假 This value has to be FALSE in RAM program.
                GBLL    PLLONSTART
PLLONSTART      SETL    {TRUE}
;PLLONSTART      SETL    {FALSE}

	GBLA	PLLCLK
PLLCLK		SETA	64000000

	[	PLLCLK = 64000000	
;系统主频计算公式如下：
;Fout = (8+ M_DIV)*Fin/[(2+P_DIV)*2]
M_DIV	EQU	56	;Fin=8MHz Fout = ((56+8)/8)*8 =64MHz   
P_DIV	EQU	2
S_DIV	EQU	1
	]

;************************************************
	END