Subversion Repositories potato

# The Potato Processor - A simple RISC-V based processor for FPGAs

# (c) Kristian Klomsten Skordal 2014 - 2015 

# Report bugs and issues on 

# Simplified timer interrupt test.

#include "riscv_test.h"

#include "test_macros.h"

#define TIMER_DELTA_T   10

#define MIE_STIE MIP_STIP

RVTEST_RV32M

RVTEST_CODE_BEGIN

        li s8, 0  # Number of timer interrupts taken

        li s9, 10 # Number of timer interrupts to wait for

        # Set the time of the next timer interrupt:

        csrr a0, mtime

        addi a0, a0, TIMER_DELTA_T

        csrw mtimecmp, a0

        # Enable the timer interrupt:

        li a0, (1 << 7)

        csrs mie, a0

        csrs mstatus, MSTATUS_IE

wait_for_count:

        # TODO: wfi not yet supported

        j wait_for_count

mtvec_handler:

        li t0, (1 << 31) + 1 # Interrupt bit set + timer interrupt exception code

        csrr t1, mcause

        bne t0, t1, fail # Fail if not timer interrupt

        addi s8, s8, 1

        beq s8, s9, pass # Pass the test if the correct number of interrupts have been taken

        # Reset the timer:

        csrr a0, mtime

        addi a0, a0, TIMER_DELTA_T

        csrw mtimecmp, a0

        eret

TEST_PASSFAIL

RVTEST_CODE_END

.data

RVTEST_DATA_BEGIN

        TEST_DATA

RVTEST_DATA_END