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|
! user.s - this is the user level code used to test the timer device
!
! this file should be loaded before the supervisor code has been
! loaded.
!
!
! One word of caution.... make sure that the user level program
! starts at location 0x20 -- or change the definition
! of MAIN in the start_timer. code
SAFE = 4000 ! the address of a safe location in the user's
! data segment -- the timer interrupt will
! increment this value
!----------------------------------------------------------------------
! start:
! just wait for a wile and print the value in
! memory location 4
!
.text
.global start
start:
! clear the value in memory location 4000
set SAFE, %i0
clr [%i0]
! set up the outer loop
set 20, %l0
top_outer:
! inner delay loop
set 400, %l1
deccc %l0
top_inner:
bne top_inner
deccc %l1
! report the value in memory location 4000
ld [%i0], %o0
ta 4
deccc %l0
bne top_outer
nop
ta 0
|
