|
1
|
//*----------------------------------------------------------------------------
|
|
2
|
//* ATMEL Microcontroller Software Support - ROUSSET -
|
|
3
|
//*----------------------------------------------------------------------------
|
|
4
|
//* The software is delivered "AS IS" without warranty or condition of any
|
|
5
|
//* kind, either express, implied or statutory. This includes without
|
|
6
|
//* limitation any warranty or condition with respect to merchantability or
|
|
7
|
//* fitness for any particular purpose, or against the infringements of
|
|
8
|
//* intellectual property rights of others.
|
|
9
|
//*----------------------------------------------------------------------------
|
|
10
|
//* File Name : Cstartup_SAM7.c
|
|
11
|
//* Object : Low level initializations written in C for GCC Tools
|
|
12
|
//* Creation : 12/Jun/04
|
|
13
|
//* 1.2 28/Feb/05 JPP : LIB change AT91C_WDTC_WDDIS & PLL
|
|
14
|
//* 1.3 21/Mar/05 JPP : Change PLL Wait time
|
|
15
|
//*----------------------------------------------------------------------------
|
|
16
|
|
|
17
|
// Include the board file description
|
|
18
|
#include <board.h>
|
|
19
|
|
|
20
|
// The following functions must be write in ARM mode this function called directly
|
|
21
|
// by exception vector
|
|
22
|
extern void AT91F_Spurious_handler (void);
|
|
23
|
extern void AT91F_Default_IRQ_handler (void);
|
|
24
|
extern void AT91F_Default_FIQ_handler (void);
|
|
25
|
|
|
26
|
//*----------------------------------------------------------------------------
|
|
27
|
//* \fn AT91F_LowLevelInit
|
|
28
|
//* \brief This function performs very low level HW initialization
|
|
29
|
//* this function can be use a Stack, depending the compilation
|
|
30
|
//* optimization mode
|
|
31
|
//*----------------------------------------------------------------------------
|
|
32
|
void
|
|
33
|
AT91F_LowLevelInit (void)
|
|
34
|
{
|
|
35
|
volatile int i;
|
|
36
|
|
|
37
|
//* Debounce power supply
|
|
38
|
for(i=0;i<1024;i++);
|
|
39
|
|
|
40
|
AT91PS_PMC pPMC = AT91C_BASE_PMC;
|
|
41
|
//* Set Flash Waite sate
|
|
42
|
// Single Cycle Access at Up to 30 MHz, or 40
|
|
43
|
// if MCK = 47923200 I have 50 Cycle for 1 usecond ( flied MC_FMR->FMCN
|
|
44
|
AT91C_BASE_MC->MC_FMR = ((AT91C_MC_FMCN) & (48 << 16)) | AT91C_MC_FWS_1FWS;
|
|
45
|
|
|
46
|
//* Set MCK at 47 923 200
|
|
47
|
// 1 Enabling the Main Oscillator:
|
|
48
|
// SCK = 1/32768 = 30.51 uSecond
|
|
49
|
// Start up time = 8 * 6 / SCK = 56 * 30.51 = 1,46484375 ms
|
|
50
|
pPMC->PMC_MOR = ((AT91C_CKGR_OSCOUNT) & (0x06 << 8)) | AT91C_CKGR_MOSCEN;
|
|
51
|
// Wait the startup time
|
|
52
|
while (!(pPMC->PMC_SR & AT91C_PMC_MOSCS));
|
|
53
|
// 2 Checking the Main Oscillator Frequency (Optional)
|
|
54
|
// 3 Setting PLL and divider:
|
|
55
|
// - div by 24 Fin = 0,7680 =(18,432 / 24)
|
|
56
|
// - Mul 125: Fout = 96,0000 =(0,7680 *125)
|
|
57
|
// for 96 MHz the erroe is 0.16%
|
|
58
|
// Field out NOT USED = 0
|
|
59
|
// PLLCOUNT pll startup time estimate at : 0.844 ms
|
|
60
|
// PLLCOUNT 28 = 0.000844 /(1/32768)
|
|
61
|
#if 0
|
|
62
|
pPMC->PMC_PLLR = ((AT91C_CKGR_DIV & 0x05) |
|
|
63
|
(AT91C_CKGR_PLLCOUNT & (28 << 8)) |
|
|
64
|
(AT91C_CKGR_MUL & (25 << 16)));
|
|
65
|
#else
|
|
66
|
pPMC->PMC_PLLR = ((AT91C_CKGR_DIV & 24) |
|
|
67
|
(AT91C_CKGR_PLLCOUNT & (28 << 8)) |
|
|
68
|
(AT91C_CKGR_MUL & (125 << 16)));
|
|
69
|
#endif
|
|
70
|
|
|
71
|
// Wait the startup time
|
|
72
|
while (!(pPMC->PMC_SR & AT91C_PMC_LOCK));
|
|
73
|
while (!(pPMC->PMC_SR & AT91C_PMC_MCKRDY));
|
|
74
|
// 4. Selection of Master Clock and Processor Clock
|
|
75
|
// select the PLL clock divided by 2
|
|
76
|
pPMC->PMC_MCKR = AT91C_PMC_PRES_CLK_2;
|
|
77
|
while (!(pPMC->PMC_SR & AT91C_PMC_MCKRDY));
|
|
78
|
|
|
79
|
pPMC->PMC_MCKR |= AT91C_PMC_CSS_PLL_CLK;
|
|
80
|
while (!(pPMC->PMC_SR & AT91C_PMC_MCKRDY));
|
|
81
|
|
|
82
|
// Set up the default interrupts handler vectors
|
|
83
|
AT91C_BASE_AIC->AIC_SVR[0] = (int) AT91F_Default_FIQ_handler;
|
|
84
|
for (i = 1; i < 31; i++)
|
|
85
|
{
|
|
86
|
AT91C_BASE_AIC->AIC_SVR[i] = (int) AT91F_Default_IRQ_handler;
|
|
87
|
}
|
|
88
|
AT91C_BASE_AIC->AIC_SPU = (int) AT91F_Spurious_handler;
|
|
89
|
|
|
90
|
}
|
