File size: 3,381 Bytes
73a586d | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 | #include <stdint.h>
#include <mips/cpu.h>
#include "mfp_memory_mapped_registers.h"
// run types
#define COMPATIBILITY 0
#define VECTOR 1
// config start
#define RUNTYPE VECTOR
#define MIPS_TIMER_PERIOD 0x200
// config end
void mipsTimerInit(void)
{
mips32_setcompare(MIPS_TIMER_PERIOD); //set compare (TOP) value to turn timer on
mips32_setcount(0); //reset counter
}
void mipsTimerReset(void)
{
mips32_setcount(0); //reset counter as it reached the TOP value
mips32_setcompare(MIPS_TIMER_PERIOD); //clear timer interrupt flag
}
void mipsInterruptInit(void)
{
#if RUNTYPE == COMPATIBILITY
//compatibility mode, one common handler
mips32_bicsr (SR_BEV); // Status.BEV 0 - place handlers in kseg0 (0x80000000)
mips32_biccr (CR_IV); // Cause.IV, 0 - general exception handler (offset 0x180)
mips32_bissr (SR_IE | SR_HINT5 | SR_SINT1); // interrupt enable, HW5,SW1 - unmasked
#elif RUNTYPE == VECTOR
//vector mode, multiple handlers
mips32_bicsr (SR_BEV); // Status.BEV 0 - place handlers in kseg0 (0x80000000)
mips32_biscr (CR_IV); // Cause.IV, 1 - special int vector (offset 0x200),
// where 0x200 - base for other vectors
uint32_t intCtl = mips32_getintctl(); // get IntCtl reg value
mips32_setintctl(intCtl | INTCTL_VS_32); // set interrupt table vector spacing (0x20 in our case)
// see exceptions.S for details
mips32_bissr (SR_IE | SR_HINT5 | SR_SINT0 | SR_SINT1); // interrupt enable, HW5 and SW0,SW1 - unmasked
#endif
}
volatile uint32_t n;
void __attribute__ ((interrupt, keep_interrupts_masked)) _mips_general_exception ()
{
MFP_RED_LEDS = MFP_RED_LEDS | 0x1;
uint32_t cause = mips32_getcr();
//check that this is interrupt exception
if((cause & CR_XMASK) == 0)
{
//check for timer interrupt
if(cause & CR_HINT5)
{
MFP_RED_LEDS = MFP_RED_LEDS | 0x10;
n++;
mipsTimerReset();
mips32_biscr(CR_SINT1); //request for software interrupt 1
MFP_RED_LEDS = MFP_RED_LEDS & ~0x10;
}
//check for software interrupt 1
else if (cause & CR_SINT1)
{
MFP_RED_LEDS = MFP_RED_LEDS | 0x8;
mips32_biccr(CR_SINT1); //clear software interrupt 1 flag
MFP_RED_LEDS = MFP_RED_LEDS & ~0x8;
}
}
MFP_RED_LEDS = MFP_RED_LEDS & ~0x1;
}
void __attribute__ ((interrupt, keep_interrupts_masked)) __mips_isr_sw0 ()
{
MFP_RED_LEDS = MFP_RED_LEDS | 0x2;
mips32_biccr(CR_SINT0); //clear software interrupt 0 flag
MFP_RED_LEDS = MFP_RED_LEDS & ~0x2;
}
void __attribute__ ((interrupt, keep_interrupts_masked)) __mips_isr_hw5 ()
{
MFP_RED_LEDS = MFP_RED_LEDS | 0x4;
n++;
mipsTimerReset();
mips32_biscr(CR_SINT0); //request for software interrupt 0
mips32_biscr(CR_SINT1); //request for software interrupt 1
MFP_RED_LEDS = MFP_RED_LEDS & ~0x4;
}
int main ()
{
n = 0;
mipsTimerInit();
mipsInterruptInit();
for (;;)
MFP_7_SEGMENT_HEX = n;
return 0;
}
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