📄 tmt.s
字号:
_TMT_Disable_Timer
; Disable the count-down timer.
; TMD_Timer_State = TM_NOT_ACTIVE;
MOV r1,#1 ; Build TM_NOT_ACTIVE value
LDR r0,Timer_State ; Build address to timer state var
STR r1,[r0,#0] ; Change timer state to not active
BX r14 ; Return to caller
;}
;************************************************************************
;*
;* FUNCTION
;*
;* TMT_Retreive_TS_Timer
;*
;* DESCRIPTION
;*
;* This function returns the time-sliced task pointer.
;*
;* CALLED BY
;*
;* TMC_Timer_HISR Timer HISR
;*
;* CALLS
;*
;* None
;*
;* INPUTS
;*
;* None
;*
;* OUTPUTS
;*
;* TMD_Time_Slice_Task Time sliced task pointer
;*
;* HISTORY
;*
;* NAME DATE REMARKS
;*
;* C. Meredith 03-01-1994 Created initial version 1.1
;* D. Lamie 03-18-1994 Verified version 1.1
;*
;************************************************************************
;NU_TASK TMT_Retrieve_TS_Task (VOID)
;{
.def $TMT_Retrieve_TS_Task
$TMT_Retrieve_TS_Task ; Dual-state interworking veneer
.state16
BX r15
NOP
.state32
B _TMT_Retrieve_TS_Task
.def _TMT_Retrieve_TS_Task
_TMT_Retrieve_TS_Task
; Read the current TMD_Time_Slice_Task variable and load for
; return to caller.
LDR r1,Slice_Task ; Build address to timer slice var
LDR r0,[r1,#0] ; Get task pointer to be returned
; Return to caller time slice value back to caller
BX r14 ; Return to caller
;}
;************************************************************************
;*
;* FUNCTION
;*
;* TMT_Timer_Interrupt
;*
;* DESCRIPTION
;*
;* This function processes the actual hardware interrupt.
;* Processing includes updating the system clock and the count-
;* down timer and the time-slice timer. If one or both of the
;* timers expire, the timer HISR is activated.
;*
;* CALLED BY
;*
;* Interrupt Vector
;*
;* CALLS
;*
;* TCT_Activate_HISR Activate timer HISR
;* TCT_Interrupt_Context_Save Save interrupted context
;* TCT_Interrupt_Context_Restore Restore interrupted context
;*
;* INPUTS
;*
;* None
;*
;* OUTPUTS
;*
;* None
;*
;* HISTORY
;*
;* NAME DATE REMARKS
;*
;* W. Lamie 02-15-1994 Created initial version 1.0
;* D. Lamie 02-15-1994 Verified version 1.0
;*
;************************************************************************
;VOID TMT_Timer_Interrupt(void)
;{
.def _TMT_Timer_Interrupt
_TMT_Timer_Interrupt
MRS r1,CPSR ; Pickup current CPSR
ORR r1,r1,#LOCKOUT ; Set the interrupt lockout bits
MSR CPSR,r1 ; Lockout interrupts
; Increment the system clock.
; TMD_System_Clock++;
LDR r0,System_Clock ; Pickup system clock address
LDR r1,[r0,#0] ; Pickup system clock contents
ADD r1,r1,#1 ; Increment system clock
STR r1,[r0,#0] ; Store new system clock value
; Determine if the count-down timer is active.
; if (TMD_Timer_State == TM_ACTIVE)
; {
LDR r1,Timer_State ; Build address to timer state flag
LDR r0,[r1,#0] ; Pickup timer state
MOV r3,#2 ; Build expired value
CMP r0,#0 ; Is there a timer active?
BNE TMT_No_Timer_Active ; No, skip timer processing
; Decrement the count-down timer.
; TMD_Timer--;
LDR r0,Timer ; Build timer address
LDR r2,[r0,#0] ; Pickup the current timer value
; Test if the Timer is at 0 and if so skip the decrement
cmp r2,#1
beq EXPIRED
SUBS r2,r2,#1 ; Decrement the timer value
STR r2,[r0,#0] ; Store the new timer value
bne TMT_No_Timer_Active ; Skip over the Set Timer State
; Determine if the timer has expired. If so, modify the state
; to indicate that it has expired.
; if (TMD_Timer == 0)
; TMD_Timer_State = TM_EXPIRED;
EXPIRED:
STREQ r3,[r1,#0] ; Change the timer state to
; expired
; }
TMT_No_Timer_Active:
; Determine if the time-slice timer is active. Note that the parameters
; for the time-slice are controlled by the Thread Control (TC)
; component.
; if (TMD_Time_Slice_State == TM_ACTIVE)
; {
LDR r0,Slice_State ; Build time slice state address
LDR r2,[r0,#0] ; Pickup time slice state
CMP r2,#0 ; Is there a time slice active?
BNE TMT_No_Time_Slice_Active ; No, skip time slice processing
; Decrement the time slice counter.
; TMD_Time_Slice--;
LDR r2,Time_Slice ; Build time slice address
LDR r3,[r2,#0] ; Pickup the time slice value
SUBS r3,r3,#1 ; Decrement the time slice
STR r3,[r2,#0] ; Store the new time slice value
; Determine if the time-slice timer has expired. If so, modify the
; time-slice state to indicate that it has.
; if (TMD_Time_Slice == 0)
; {
BNE TMT_No_Time_Slice_Active ; Has time slice expired?
; TMD_Time_Slice_State = TM_EXPIRED;
MOV r3,#2 ; Build TM_EXPIRED value
STR r3,[r0,#0] ; Indicate time slice is expired
; Copy the current thread into the time-slice task pointer.
; TMD_Time_Slice_Task = TCD_Current_Thread;
LDR r2,Current_Thread ; Pickup current thread pointer adr
LDR r2,[r2,#0] ; Pickup current thread pointer
LDR r3,Slice_Task ; Pickup time slice task pointer ad
STR r2,[r3,#0] ; Store current thread pointer
; ((TC_TCB *) TCD_Current_Thread) -> tc_cur_time_slice = 1;
MOV r3,#1 ; For safety, place a minimal time-
STR a4,[a3,#20h]! ; slice into the task's control
; block
; }
; }
TMT_No_Time_Slice_Active:
; Determine if either of the basic timers have expired. If so,
; activate the timer HISR.
; if ((TMD_Timer_State == TM_EXPIRED) ||
; (TMD_Time_Slice_State == TM_EXPIRED))
; {
LDR r1,[r1,#0] ; Pickup timer state
CMP r1,#2 ; Does it indicate expiration?
LDRNE r0,[r0,#0] ; Pickup time slice state
CMPNE r0,#2 ; Does it indicate expiration?
BXNE r14 ; Return if no expiration
; Activate the HISR timer function.
; TCT_Activate_HISR(&TMD_HISR);
STR r14,[r13, #-4]! ; Save r14 on the stack
LDR r0,HISR ; Build address of timer HISR
BL _TCT_Activate_HISR ; Activate timer HISR
LDR r14,[r13], #4 ; Recover return address
; }
BX r14 ; Return to caller
;}
.end
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -