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可以
- |* Q! l& z1 t' C/ C" E- o/ }2 l不过这个通常是需要看MCU的手册的，按照MCU手册上面的关于MEM CLOCK这部分# c- r0 z) i4 \" K
6 Q: C, `1 n3 T
通常在系统启动的时候进行寄存器部分的设置拿三星的2410来说' y1 s# r8 G. ?+ N/ \0 I
AREA Init,CODE,READONLY: f4 `, s% c! \3 T7 i, H
ENTRY
7 c9 j# T7 J3 N _: g8 u b HandlerUndef ;handler for Undefined mode7 H2 `8 H3 p$ r
b HandlerSWI ;handler for SWI interrupt$ t3 q7 C* f9 {1 M. O( _; x
b HandlerPabort ;handler for PAbort# j4 o+ m8 {9 l; j# c4 _4 c. U
b HandlerDabort ;handler for DAbort4 ] p4 S4 j" C" h2 u- ]2 z8 J
b . ;reserved3 e4 R4 }& R9 @* r# ?: D
b HandlerIRQ ;handler for IRQ interrupt # R( G! x* {# L. T
b HandlerFIQ ;handler for FIQ interrupt, i0 @# _+ v! n5 L% X8 I$ h& M8 _
初始化中断向量表。。。。- [% j- p% `% C# {
在初始化堆栈前必须做外部SDRAM内存的硬件初始化，这个时候就会根据硬件手册设置好相应的
# c5 A. l+ @5 b7 D. q% v....................
: H9 D0 s" L: f, u$ @ ;Set memory control registers3 y8 ?' K1 R& q% s) E
ldr r0,=SMRDATA
, |, {1 P5 C6 I8 V+ k9 |( Y ldr r1,=BWSCON ;BWSCON Address" F0 h3 G5 {% h
add r2, r0, #52 ;End address of SMRDATA% {7 M) t, O; z$ ~
.................: M4 N2 G v/ B
;@0x20% ~" k9 g ~ [# x8 |$ i5 m
b EnterPWDN
( f# K! X4 w9 P; u c: E' NSMRDATA DATA$ k, V' I$ t- h) @* {, z
; Memory configuration should be optimized for best performance
( O" p. G2 I* |6 U; ~$ m; The following parameter is not optimized.
1 ~8 k x* [4 u4 u" E+ A/ h; S; Memory access cycle parameter strategy6 Q0 |6 e2 q& @
; 1) The memory settings is safe parameters even at HCLK=75Mhz.! A# w* X* Z# E" f! a/ F
; 2) SDRAM refresh period is for HCLK=75Mhz.
8 x( A* h7 r' }. Z7 P3 k2 d9 d% Q! s6 `9 N# k" Q6 t& H2 g, y2 X
DCD (0+(B1_BWSCON<<4)+(B2_BWSCON<<8)+(B3_BWSCON<<12)+(B4_BWSCON<<16)+(B5_BWSCON<<20)+(B6_BWSCON<<24)+(B7_BWSCON<<28))
0 L) h- I6 [" U& N/ [ DCD ((B0_Tacs<<13)+(B0_Tcos<<11)+(B0_Tacc<<8)+(B0_Tcoh<<6)+(B0_Tah<<4)+(B0_Tacp<<2)+(B0_PMC)) ;GCS0
) X1 U- S8 ], j( C6 E- k2 { DCD ((B1_Tacs<<13)+(B1_Tcos<<11)+(B1_Tacc<<8)+(B1_Tcoh<<6)+(B1_Tah<<4)+(B1_Tacp<<2)+(B1_PMC)) ;GCS1 . Z, ]" r' @6 ?; R+ N, M
DCD ((B2_Tacs<<13)+(B2_Tcos<<11)+(B2_Tacc<<8)+(B2_Tcoh<<6)+(B2_Tah<<4)+(B2_Tacp<<2)+(B2_PMC)) ;GCS2
5 K" N6 Z* d; a9 M DCD ((B3_Tacs<<13)+(B3_Tcos<<11)+(B3_Tacc<<8)+(B3_Tcoh<<6)+(B3_Tah<<4)+(B3_Tacp<<2)+(B3_PMC)) ;GCS3
; ^+ K. z$ h1 n# } DCD ((B4_Tacs<<13)+(B4_Tcos<<11)+(B4_Tacc<<8)+(B4_Tcoh<<6)+(B4_Tah<<4)+(B4_Tacp<<2)+(B4_PMC)) ;GCS4
& x* x/ Z/ x+ G0 W6 _ DCD ((B5_Tacs<<13)+(B5_Tcos<<11)+(B5_Tacc<<8)+(B5_Tcoh<<6)+(B5_Tah<<4)+(B5_Tacp<<2)+(B5_PMC)) ;GCS5
/ u2 M# b/ d9 Z$ E' ^ I( i/ z DCD ((B6_MT<<15)+(B6_Trcd<<2)+(B6_SCAN)) ;GCS6( y9 Y, R3 y- b3 q- q- Z. U
DCD ((B7_MT<<15)+(B7_Trcd<<2)+(B7_SCAN)) ;GCS7# F$ s- C& @2 ]9 @/ q
; DCD ((REFEN<<23)+(TREFMD<<22)+(Trp<<20)+(Trc<<18)+(Tchr<<16)+REFCNT) ;Tchr not used bit
5 i8 h; L7 A6 {7 e/ t DCD ((REFEN<<23)+(TREFMD<<22)+(Trp<<20)+(Trc<<18)+REFCNT) 0 N; H0 E/ n4 |. _3 Q ^/ H* F3 ?7 G
; Q1 s, A4 l' N. A3 m% W" S0 o- M M$ X0 L0 m- r, c$ E$ ~
5 K0 ^( j2 a0 S; H3 Q0 ~- k( M N
; DCD 0x32 ;SCLK power saving mode, ARM core burst disable, BANKSIZE 128M/128M
# E2 [4 Z5 }* t# o/ m DCD 0xb2 ;SCLK power saving mode, ARM core burst enable , BANKSIZE 128M/128M - 11/29/2002
6 N! Q4 a4 K* j8 N1 A
& _- M% `, m& A7 M2 r DCD 0x30 ;MRSR6 CL=3clk
% P' p% c8 {2 r8 r5 [( g DCD 0x30 ;MRSR7
# Y, W% U( u- C" N; DCD 0x20 ;MRSR6 CL=2clk/ O$ G; w* A. v: {
; DCD 0x20 ;MRSR7 |
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发表于 2009-7-6 10:21
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