| Line 1... |
Line 1... |
; irq_test.a51 -- First interrupt service test.
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; irq_test.a51 -- Basic interrupt service test.
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;
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;
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; This progam is only meant to work in the simulation test bench, because it
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; This program is only meant to work in the simulation test bench, because it
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; requires the external interrupt inputs to be wired to the P1 output port.
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; requires the external interrupt inputs to be wired to the P1 output port.
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; They are in the simulation test bench entity but not in the synthesizable
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; They are in the simulation test bench entity but not in the synthesizable
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; demo top entity.
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; demo top entity.
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;
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;
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; Its purpose is to demonstrate the working of the interrupt service logic. No
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; Its purpose is to demonstrate the working of the interrupt service logic. No
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; actual tests are performed (other than the co-simulation tests), only checks.
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; actual tests are performed (other than the co-simulation tests), only checks.
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;
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;
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; This program makes the following assumptions about the MCU configuration:
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;
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; 1.- Port line P1.0 is wired to external input EXTINT0.0
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; 2.- The timer prescaler is set to 20us@50MHz.
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;
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; NOTE: I am aware that this code is perfectly hideous and nearly useless as a
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; test bench; it will have to do for the time being. I can seldom find quality
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; time for this project...
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;-------------------------------------------------------------------------------
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;-------------------------------------------------------------------------------
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; Include the definitions for the light52 derivative
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; Include the definitions for the light52 derivative
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$nomod51
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$nomod51
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$include (light52.mcu)
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$include (light52.mcu)
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ext_irq_ctr set 060h ; Incremented by external irq routine
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ext_irq_ctr set 060h ; Incremented by external irq routine
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timer_irq_ctr set 062h ; Incremented by timer irq routine
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uart_irq_ctr set 063h ; Incremented by uart irq routine
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irq_test_code set 064h ; Selects the behavior of the irq routines
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;-- Macros -------------------------------------------------------------
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;-- Macros -------------------------------------------------------------
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; putc: send character in A to console (UART)
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; putc: send character in A to console (UART)
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putc macro character
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putc macro character
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local putc_loop
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local putc_loop
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mov SBUF,character
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mov SBUF,character
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putc_loop:
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putc_loop:
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; This program will only ever run in the simulated environment, where
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; UART transmission is instantaneous. No need to loop here.
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;mov a,SCON
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;mov a,SCON
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;anl a,#10h
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;anl a,#10h
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;jz putc_loop
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;jz putc_loop
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endm
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endm
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| Line 52... |
Line 65... |
ljmp irq_wrong
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ljmp irq_wrong
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;-- Main test program --------------------------------------------------
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;-- Main test program --------------------------------------------------
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org 30h
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org 30h
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; Place a few utility routines here at the start so they are reachable
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; by CJNE.
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; Did not get expected IRQ: print failure message and block.
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fail_expected:
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mov DPTR,#text3
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call puts
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mov IE,#00h
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ajmp $
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; Got unexpected IRQ: print failure message and block.
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fail_unexpected:
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mov DPTR,#text1
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call puts
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mov IE,#00h
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ajmp $
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start:
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start:
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; Disable all interrupts.
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mov IE,#00 ; Disable all interrupts...
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mov IE,#00
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mov IP,#01 ; ...and set EXTINT as high-priority.
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mov irq_test_code,#00h ; Tell irq routines to only inc the counters
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;---- External interrupt test --------------------------------------
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;---- External interrupt test --------------------------------------
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; Basic interrupt test.
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; We'll be asserting the external interrupt request line 0, making
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; We'll be asserting the external interrupt request line 0, making
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; sure the interrupt enable flags work properly. No other interrupt
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; sure the interrupt enable flags work properly. No other interrupt
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; will be asserted simultaneously or while in the interrupt service
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; will be asserted simultaneously or while in the interrupt service
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; routine.
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; routine.
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| Line 82... |
Line 117... |
nop ; Wait a little...
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nop ; Wait a little...
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nop
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nop
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nop
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nop
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mov a,ext_irq_ctr ; ...and make sure the interrupt was NOT
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mov a,ext_irq_ctr ; ...and make sure the interrupt was NOT
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cjne a,#00,fail_unexpected ; serviced.
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cjne a,#00,fail_unexpected ; serviced.
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setb EXTINT0.0 ; Clear timer IRQ flag
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setb EXTINT0.0 ; Clear external IRQ flag
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; Trigger external IRQ with external and global IRQ enabled
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; Trigger external IRQ with external and global IRQ enabled
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mov P1,#00h ; Clear the external interrupt line...
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mov P1,#00h ; Clear the external interrupt line...
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mov IE,#81h ; ...before enabling interrupts globally.
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mov IE,#81h ; ...before enabling interrupts globally.
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mov ext_irq_ctr,#00 ; Reset the interrupt counter...
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mov ext_irq_ctr,#00 ; Reset the interrupt counter...
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| Line 94... |
Line 129... |
nop ; Give it some time to be acknowledged...
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nop ; Give it some time to be acknowledged...
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nop
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nop
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nop
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nop
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mov a,ext_irq_ctr ; ...and make sure it has been serviced.
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mov a,ext_irq_ctr ; ...and make sure it has been serviced.
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cjne a,#01,fail_expected
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cjne a,#01,fail_expected
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setb EXTINT0.0 ; Clear timer IRQ flag
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setb EXTINT0.0 ; Clear external IRQ flag
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; Somewhat less basic interrupt test: priorities.
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; Here we are going to use the test code byte (irq_test_code) to tell
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; the interrupt routines what we want them to do. Since we only use two
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; interrupt routines to test everything, each routine has to perform
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; a few different roles.
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; Basically we want to make sure that the irq priority rules hold:
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;
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; A.-Nothing can interrupt a high priority irq routine.
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; B.- Only a high-priority irq can interrupt a low-priority irq.
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; C.- Simultaneous irqs get ordered by their vector number.
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;
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; Rule C will NOT be tested in this program; and rules B and A get only
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; the most basic of basic tests.
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; Run test 1: Trigger another external interrupt while serving an
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; external interrupt. Since both are high-priority, the timer interrupt
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; should be ignored.
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mov irq_test_code,#01h
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mov P1,#00h ; Clear the external interrupt line...
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mov IE,#83h ; ...before enabling interrupts globally.
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mov ext_irq_ctr,#00 ; Reset the interrupt counter...
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mov P1,#01h ; ...and assert the external interrupt.
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nop ; Give it some time to be acknowledged...
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nop
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mov a,ext_irq_ctr ; ...and make sure it has been serviced.
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cjne a,#01,fail_expected
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setb EXTINT0.0 ; Clear external IRQ flag
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; Run test 2: Trigger Timer interrupt while serving an external
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; interrupt. Since the Timer irq is low-priority, it should be ignored.
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mov irq_test_code,#02h
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mov P1,#00h ; Clear the external interrupt line...
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mov IE,#83h ; ...before enabling interrupts globally.
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mov ext_irq_ctr,#00 ; Reset the interrupt counter...
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mov P1,#01h ; ...and assert the external interrupt.
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nop ; Give it some time to be acknowledged...
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nop
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mov a,ext_irq_ctr ; ...and make sure it has been serviced.
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cjne a,#01,fail_expected
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setb EXTINT0.0 ; Clear external IRQ flag
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; Run test 3: Trigger interrupts within the timer interrupt service
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; routine.
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mov irq_test_code,#03h
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mov timer_irq_ctr,#00h
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mov P1,#00h ; Clear the external interrupt line...
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mov IE,#83h ; ...before enabling interrupts globally.
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mov ext_irq_ctr,#00 ; Reset the interrupt counter...
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mov TSTAT,#01 ; Stop timer and clear timer interrupt...
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mov TH,#00h ; ...set counter = 000h...
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mov TL,#00h ;
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mov TCH,#00h ; ...and set Compare register = 0001h...
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mov TCL,#01h ;
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mov TSTAT,#030h ; ...then start counting.
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mov r1,#95 ; Wait for the timer IRQ to trigger...
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loop_001:
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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djnz r1,loop_001 ; ...then make sure the timer irq has
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mov a,timer_irq_ctr ; been triggered.
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cjne a,#01h,fail_expected_irq_bridge
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; End of irq test, print message and continue
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; End of irq test, print message and continue
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mov DPTR,#text2
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mov DPTR,#text2
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call puts
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call puts
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| Line 107... |
Line 212... |
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; All we will do here is make sure the counter changes at the right
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; All we will do here is make sure the counter changes at the right
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; time, i.e. 20us after being started. We will NOT test the full
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; time, i.e. 20us after being started. We will NOT test the full
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; functionality of the timer (not in this version of the test).
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; functionality of the timer (not in this version of the test).
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; Note that the irq tests above already assume the timer works... this
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; test is somewhat redundant.
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mov IE,#000h ; Disable all interrupts...
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mov IE,#000h ; Disable all interrupts...
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; ...and put timer in
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; ...and put timer in
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mov TSTAT,#00 ; Stop timer...
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mov TSTAT,#00 ; Stop timer...
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mov TH,#00 ; ...set counter = 0...
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mov TH,#00 ; ...set counter = 0...
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mov TL,#00 ;
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mov TL,#00 ;
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| Line 145... |
Line 253... |
call puts
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call puts
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;-- End of test program, enter single-instruction endless loop
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;-- End of test program, enter single-instruction endless loop
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quit: ajmp $
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quit: ajmp $
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fail_expected_irq_bridge:
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jmp fail_expected_irq
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fail_timer_error:
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fail_timer_error:
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mov DPTR,#text4
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mov DPTR,#text4
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call puts
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call puts
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mov IE,#00h
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mov IE,#00h
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ajmp $
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ajmp $
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; Did not get expected IRQ: print failure message and block.
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fail_expected:
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mov DPTR,#text3
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call puts
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mov IE,#00h
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ajmp $
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; Got unexpected IRQ: print failure message and block.
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fail_unexpected:
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mov DPTR,#text1
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call puts
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mov IE,#00h
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ajmp $
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; End of the test code. Now let's define a few utility routines.
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; End of the test code. Now let's define a few utility routines.
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;-- puts: output to UART a zero-terminated string at DPTR ----------------------
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;-- puts: output to UART a zero-terminated string at DPTR ----------------------
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puts:
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puts:
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mov r0,#00h
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mov r0,#00h
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| Line 183... |
Line 278... |
putc a
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putc a
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sjmp puts_loop
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sjmp puts_loop
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puts_done:
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puts_done:
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ret
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ret
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;-- irq_timer: interrupt routine for timer -------------------------------------
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;-- irq_ext: interrupt routine for external irq lines --------------------------
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; Note we don't bother to preserve any registers.
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; Note we don't bother to preserve any registers.
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irq_ext:
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irq_ext:
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mov P1,#00h ; Remove the external interrupt request
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mov P1,#00h ; Remove the external interrupt request
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mov EXTINT0,#0ffh ; Clear all external IRQ flags
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mov EXTINT0,#0ffh ; Clear all external IRQ flags
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inc ext_irq_ctr ; Increment irq counter
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inc ext_irq_ctr ; Increment irq counter
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; Ok, now check the test code byte to see what we have to do here.
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mov a,irq_test_code
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cjne a,#00h,irq_ext_0
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; Test 0: Just increment irq counter (already done).
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mov DPTR,#text0 ; Print IRQ message...
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mov DPTR,#text0 ; Print IRQ message...
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call puts
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call puts
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reti ; ...and quit
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reti ; ...and quit
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irq_ext_0:
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cjne a,#02h,irq_ext_1
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; Test 2: Trigger timer interrupt while in the service routine.
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; Verify that low-priority interrupts get ignored while in the service
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; routine of a high-priority interrupt.
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mov timer_irq_ctr,#00h
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mov TSTAT,#01 ; Stop timer and clear timer interrupt...
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mov TH,#00h ; ...set counter = 000h...
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mov TL,#00h ;
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mov TCH,#00h ; ...and set Compare register = 0001h.
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mov TCL,#01h ;
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mov IE,#82h ; Enable timer interrupt...
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mov TSTAT,#030h ; ...and start counting.
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mov r0,#95 ; Wait for the timer interrupt to trigger...
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irq_ext_test0_loop0:
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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djnz r0,irq_ext_test0_loop0 ; ...the make sure the timer irq has
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mov a,timer_irq_ctr ; NOT triggered.
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cjne a,#00h,fail_unexpected_irq
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reti
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irq_ext_1:
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cjne a,#01h,irq_ext_2
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; Test 1: Trigger external interrupt while in the service routine.
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; Verify that high-priority interrupts get ignored while in the service
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; routine of another high-priority interrupt.
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mov ext_irq_ctr,#00h
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mov irq_test_code,#00h
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mov IE,#81h ; ...enable the UART irq...
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mov P1,#01h ; ...and trigger it
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mov r0,#10 ; Give time for the irq to trigger...
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irq_ext_test2_loop0:
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nop
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djnz r0,irq_ext_test2_loop0 ; ...the make sure the Timer irq has
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mov a,ext_irq_ctr ; NOT triggered.
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cjne a,#00h,fail_unexpected_irq
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reti
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irq_ext_2:
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; Code byte irq_test_code not used; ignored.
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reti
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;-- irq_timer: interrupt routine for timer -------------------------------------
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; Note we don't bother to preserve any registers.
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irq_timer:
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irq_timer:
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; Check the test code to see what we have to do here.
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mov a,irq_test_code
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cjne a,#03,irq_timer_0
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; Test code 3: interrupts within timer irq service routine.
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; Trigger external interrupt within this irq service routine and make
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; sure it gets serviced.
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mov ext_irq_ctr,#00h
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mov irq_test_code,#00h
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mov IE,#81h ; ...enable the UART irq...
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mov P1,#01h ; ...and trigger it
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mov r0,#10 ; Give time for the irq to trigger...
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irq_timer_test3_loop0:
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nop
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djnz r0,irq_timer_test3_loop0 ; ...the make sure the Timer irq has
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mov a,ext_irq_ctr ; NOT triggered.
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cjne a,#01h,fail_expected_irq
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; Ok, now re-trigger the timer interrupt within the timer service
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; interrupt and make sure the new interrupt is not serviced.
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mov irq_test_code,#00h
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mov timer_irq_ctr,#00h
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mov TSTAT,#01 ; Stop timer and clear timer interrupt...
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mov TH,#00h ; ...set counter = 000h...
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mov TL,#00h ;
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mov TCH,#00h ; ...and set Compare register = 0001h...
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mov TCL,#01h ;
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mov TSTAT,#030h ; ...then start counting.
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mov r1,#95 ; Wait for the timer IRQ to trigger...
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irq_timer_test3_loop1:
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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djnz r1,irq_timer_test3_loop1 ; ...then make sure the timer irq has
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mov a,timer_irq_ctr ; been ignored.
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cjne a,#00h,fail_unexpected_irq
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inc timer_irq_ctr ; Increment timer interrupt counter...
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mov TSTAT,#01 ; Stop timer and clear timer interrupt.
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reti
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irq_timer_0:
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; Test code 0: increment irq counter.
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; Just increment the timer irq counter and quit.
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inc timer_irq_ctr ; Increment timer interrupt counter...
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mov TSTAT,#01 ; Stop timer and clear timer interrupt.
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reti ; ...and quit.
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irq_wrong:
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irq_wrong:
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ajmp irq_wrong
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ajmp irq_wrong
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; Utility functions -- error messages to console, etc.
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; Got unexpected IRQ: print failure message and block.
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fail_unexpected_irq:
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mov DPTR,#text1
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call puts
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mov IE,#00h
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ajmp $
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; Did not get expected IRQ: print failure message and block.
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fail_expected_irq:
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mov DPTR,#text3
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call puts
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mov IE,#00h
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ajmp $
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; End of the utility routines. Define constant data and we're done.
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; End of the utility routines. Define constant data and we're done.
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text0: db '',13,10,00h,00h
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text0: db '',13,10,00h,00h
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text1: db 'Unexpected IRQ',13,10,00h,00h
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text1: db 'Unexpected IRQ',13,10,00h,00h
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text2: db 'IRQ test finished, no errors',13,10,0
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text2: db 'IRQ test finished, no errors',13,10,0
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