;
;----------------------------------------------------------------------------
;
; Copyright (c) 1992 Tiger Labs, Corp. All Rights Reserved.
;
; This Source File Represents An Unpublished Work Of Tiger Labs, And May
; Not Be Copied, Duplicated Or Reproduced In Any Form Or Manner, Mechanical
; Or Electronic, Or By Any Means Not Mentioned Here, Without Prior Written
; Permission Of Tiger Labs, Corp.
;
;----------------------------------------------------------------------------
;
; RSG.ASM - The Ready-Set-Go! Boat Racing Timer. Version 1.00.
;
; Notes:
;
; The LCD Is Connected Sort Of Funny. The High Order Digit Is Used To
; Control The 1, The LOBAT Symbol, And The Colon. LCD Segments Are Numbered
; Clockwise, With 'A' Being At The Top, 'F' Being The Upper Left Segment,
; And 'G' Being The Center Horizontal Segment.
;
;
;----------------------------------------------------------------------------
;
; EQUATES For This Module
;
P87C751 equ -1 ; 0 For Emulator, -1 For 87C751 Processor
;
PUPTIM equ 180 ; Unit Stays On For 3 Minutes Of Inactivity
PDNTIM equ 30 ; If 0:00 And No Activity, 30 Seconds
HRNPON equ 5 ; Horn Time At Power On
HRNEXP equ 150 ; Horn Time For 0:00 (# 20ms Intervals)
HRNWRN equ 50 ; Horn Time For 5:00, 1:00
HRNLTS equ 25 ; Horn Time For 0:10 ... 0:01
ELPTIM equ 50 ; This Is 1 / Timer Rate
;
DEFSEC equ 0 ; 0 Seconds On Display At Startup
DEFMIN equ 10 ; 10 Minutes On Display At Startup
;
DIGIT0 equ 11000000b ; Bits To Select Digit 0
DIGIT1 equ 10000000b ; Bits To Select Digit 1
DIGIT2 equ 01000000b ; Bits To Select Digit 2
DIGIT3 equ 00000000b ; Bits To Select Digit 3
;
POS_GO bit acc.0 ; Bit Position For GO Switch
POS_SET bit acc.1 ; Bit Position For SET Switch
VAL_GO equ 001h ; Value For GO Switch
VAL_SET equ 002h ; Value For SET Switch
VAL_RST equ 003h ; Value For RST Switch
;
; Set Timing Constants
;
if P87C751
CLOCK equ 3 ; 1 For 12Mhz, 2 For 6Mhz, 3 For 4Mhz
TMRRATE equ 0-(20000/CLOCK) ; Switch Polled Every 20 Milliseconds
;
else
;
CLOCK equ 1 ; 1 For 12Mhz, 2 For 6Mhz, 3 For 4Mhz
TMRRATE equ 0-(20000/CLOCK) ; Switch Polled Every 20 Milliseconds
endif
;
; Define Port Equates. Determine If On 87C751 Or Emulator
;
if P87C751
DATA0 bit p3.0 ; Data Line 0 For LCD Controller
DATA1 bit p3.1 ; Data Line 1 For LCD Controller
DATA2 bit p3.2 ; Data Line 2 For LCD Controller
DATA3 bit p3.3 ; Data Line 3 For LCD Controller
DS1 bit p3.4 ; Data Register Select 0 For LCD Controller
DS2 bit p3.5 ; Data Register Select 1 For LCD Controller
LCDCS bit p3.6 ; Chip Select For LCD Controller (Active Low)
HORN bit p3.7 ; Piezo Horn Bit (Active Low)
;
SWT_GO bit p1.0 ; GO Switch Input (Active Low)
SWT_SET bit p1.1 ; SET Switch Input (Active Low)
LOW_BAT bit p1.2 ; Low Battery Warning Input
CPU_ON bit p1.3 ; CPU Power Control Output (Active Low)
;
else
;
DATA0 bit p1.0 ; Data Line 0 For LCD Controller
DATA1 bit p1.1 ; Data Line 1 For LCD Controller
DATA2 bit p1.2 ; Data Line 2 For LCD Controller
DATA3 bit p1.3 ; Data Line 3 For LCD Controller
DS1 bit p1.4 ; Data Register Select 0 For LCD Controller
DS2 bit p1.5 ; Data Register Select 1 For LCD Controller
LCDCS bit p1.6 ; Chip Select For LCD Controller (Active Low)
HORN bit p1.7 ; Piezo Horn Bit (Active Low)
;
SWT_GO bit p3.2 ; GO Switch Input (Active Low)
SWT_SET bit p3.3 ; SET Switch Input (Active Low)
CPU_ON bit p3.4 ; CPU Power Control Output (Active Low)
LOW_BAT bit p3.5 ; Low Battery Warning Input
endif
page
;
;----------------------------------------------------------------------------
;
; Equates For Registers Processor Doesn't Know About. These Are In Lower Case
; Since They're Processor Registers, And Not User Variables.
;
i2con equ 098h ; I2C Bus Control Register
i2dat equ 099h ; I2C Bus Data Register
i2cfg equ 0d8h ; I2C Bus Configuration Register
i2str equ 0f8h ; I2C Bus Status Register
i2ine bit ie.4 ; I2C Interrupt Enable Bit
;
tl equ 08ah ; Timer Low Byte
th equ 08ch ; Timer High Byte
tlr equ 08bh ; Timer Low Reload Byte
thr equ 08dh ; Timer High Reload Byte
page
;
;----------------------------------------------------------------------------
;
; Data Storage Locations
;
rseg bit
TMRRUN ds 1 ; Timer Running In Interrupt Loop When Set
TMRDONE ds 1 ; Timer Has Reached 0 Flag When Set
PWROFF ds 1 ; Time To Power Off When Set
HRNSND ds 1 ; Sound Horn While Set
LBSTAT ds 1 ; Low Battery Status
MODESPG ds 1 ; Switch Press Good If Set
MODESWT ds 1 ; Current Mode Of Switch
;
rseg data
TIMSEC ds 1 ; Seconds Counter
TIMMIN ds 1 ; Minutes Counter
SWTSTAT ds 1 ; Switch Status
PWRTMR ds 1 ; Power Off Delay Counter
HRNTMR ds 1 ; Horn Timer
SECELP ds 1 ; 10 Millisecond Counter
TOS ds 22 ; Top Of Stack Pointer
page
;
;----------------------------------------------------------------------------
;
; Systems Always Powers Up To Location 0. Set Up Interrupt, Etc
;
cseg
ajmp SSTART ; Reset Vector
db 0 ; 1 NOP
reti ; Return From IE0 Interrupt
db 0,0,0,0,0,0,0 ; 7 NOPS
ajmp SWITCH ; Process TF0 Interrupt
db 0,0,0,0,0,0 ; 6 NOPS
reti ; Return From IE1 Interrupt
db 0,0,0,0,0,0,0 ; 7 NOPS
reti ; Return From TF1 Interrupt
db 0,0,0,0,0,0,0 ; 7 NOPS
reti ; Return From I2C Interrupt
page
;
;----------------------------------------------------------------------------
;
; Copyright Notice (Even Though Security Bit Is Burned), And Obligatory
; Self Praise, And Ownership Rights.
;
db 'Copyright (c) 1992 By Tiger Labs, Corp.'
db 'All Rights Reserved.'
db 'Version 1.00'
db 0
db 'Tiger Labs Corporation'
db '100 Nobel Court'
db 'Alpharetta, GA 30202'
db '404-475-8789'
db 0
db 'Written By John C. Wren'
db 0
;
;----------------------------------------------------------------------------
;
; SSTART - System Entry Point. Configure Parameters
;
SSTART mov sp,#TOS ; Set Stack Pointer
mov ie,#000h ; No Interrupts (Yet)
mov psw,#000h ; Clear Flags, Select Register Set 0
mov pcon,#000h ; No Power Down
;
; Now Setup Timers Modes. Actual Timer Rate Set By ISR
;
acall PTINIT ; Init Ports
acall E0INIT ; Init External Interrupt 0
acall E1INIT ; Init External Interrupt 1
acall ICINIT ; Init I2C Bus Interface
acall SWINIT ; Init Switches
acall PWINIT ; Init Power
acall TMINIT ; Init Second Counter
acall HNINIT ; Init Horn
acall LBINIT ; Init Low Battery Status
acall T0INIT ; Init Timer 0
acall T1INIT ; Init Timer 1
setb ea ; Enable Entire Interrupt Structure
ajmp USTART ; Go Start User Code
;
;----------------------------------------------------------------------------
;
; USTART - Start Of User Code
;
USTART mov TIMSEC,#DEFSEC ; Default Seconds
mov TIMMIN,#DEFMIN ; Default Minutes
acall DSPDIG ; Display Current Timer
;
; Power Down Processor. Timer Events Wake Us Up.
;
UST1 clr MODESPG ; Acknowledge Button Press, If Any
orl pcon,#00000001b ; Set Power Down Mode
nop ; Safety Net
jb TMRDONE,UST2 ; If Timer Done, Go Enable Horn
jb PWROFF,UST3 ; Timer To Power Off? Snooooooze.
jb MODESPG,UST4 ; If Button Was Pressed, Deal With It...
sjmp UST1 ; Huh? Well, Just Go Back To Sleep...
;
; Timer Expired, So Enable Horn
;
UST2 mov HRNTMR,#HRNEXP ; Setup Horn Timer On Duration
setb HRNSND ; Enable Horn
clr TMRDONE ; Don't Keep Setting Off Horn
mov SECELP,#1 ; Reset Counter
sjmp UST1 ; And Go Back To Sleep
;
; Power Timer Expired, So Shut Us Down
;
UST3 clr CPU_ON ; Turn Us Off
sjmp UST3 ; Don't Wander Around Memory
;
; Must Have Had Button Press. Figure Out What To Do.
;
UST4 mov a,SWTSTAT ; Get Switch Value
cjne a,#VAL_RST,UST5 ; If Not RST Switch, Skip
clr TMRRUN ; Timer Not Running
clr TMRDONE ; Timer Not Done
mov TIMSEC,#DEFSEC ; Default Seconds
mov TIMMIN,#DEFMIN ; Default Minutes
acall DSPDIG ; Display Current Timer
sjmp UST1 ; Go Back To Sleep
;
UST5 cjne a,#VAL_GO,UST6 ; If Not Run Switch, Skip
acall CHKZERO ; See If Time At 0:00
jz UST1 ; If So, Don't Do Anything
mov SECELP,#ELPTIM ; Setup Second Elapsed Counter
setb TMRRUN ; Start Timer Running
sjmp UST1 ; Make It So, Number 1
;
UST6 cjne a,#VAL_SET,UST7 ; If Not Set Switch, Skip
jb TMRRUN,UST1 ; Can't Change Timer While Running
acall SETDEC ; Decrement Minutes
acall DSPDIG ; Display Current Timer
sjmp UST1 ; Go Back To Sleep
;
UST7 sjmp UST1 ; Go Back To Sleep
page
;
;----------------------------------------------------------------------------
;
; SWITCH - Handles Polling The Switch.
;
SWITCH push psw ; Save PSW
push acc ; Save A
;
; If Running Emulator, Reload The Standard 8051 Style Timer
;
if !P87C751
clr tr0 ; Stop Counter
mov a,#low (TMRRATE+7); Get Reset Value
add a,tl0 ; Add Timer Overflow Count
mov tl0,a ; Reset Timer Low
mov a,#high (TMRRATE+7); Get Reset Value
addc a,th0 ; Add Overflow Value
mov th0,a ; Reset Timer High
setb tr0 ; Start Timer Running Again
endif
;
; Unless It's A 1 Second Interval, Don't Check The Timeout Timer, And Don't
; Decrement The Timer Display.
;
mov a,SECELP ; Get Second Counter
dec a ; Decrement It
mov SECELP,a ; Store It Back
jnz SWT2 ; If Not 0, Don't Decrement Power Off Counter
mov SECELP,#ELPTIM ; Reset Counter
;
; If Timer Running, Decrement The Timer Value, And Update Display. If The
; Timer Value Goes To 0, Set The TMRDONE Flag.
;
jnb TMRRUN,SWT1 ; If Timer Not Running, Skip
acall DECTIME ; Decrement The Time
acall DSPDIG ; Display Current Timer
acall CHKHORN ; See If We Need To Sound Horn Based On Time
;
; If Timer Not Running, Horn Not Sounding, And No Keystrokes, Then Decrement
; The Power Off Timer. If It Goes To 0, Set The PWROFF Bit.
;
SWT1 jb TMRRUN,SWT2 ; If Timer Running, Don't Do Power Off Timer
jb HRNSND,SWT2 ; If Horn Sounding, Don't Do Power Off Timer
mov a,PWRTMR ; Get Power Off Counter
dec a ; Decrement It
mov PWRTMR,a ; Store It Back
jnz SWT2 ; If Not 0, Don't Set Power Off
setb PWROFF ; Tell Unit To Go Sleepyby...
;
; Check The HRNSND Bit. If Set, Then Start Decrementing The Horn Timer. Once
; The Horn Timer Goes To 0, Disable The Horn, And Reset The Horn Timer.
;
SWT2 jnb HRNSND,SWT3 ; If Horn Not Sounding, Skip
clr HORN ; Enable Horn
mov a,HRNTMR ; Get Horn Duration Timer
dec a ; Decrement Horn Timer
mov HRNTMR,a ; Store Horn Duration Timer Back
jnz SWT6 ; While Not 0, Don't Disable Horn
clr HRNSND ; Mark Horn As Not Sounding
setb HORN ; Disable Horn
;
; Check Battery Low Status. If A Change In It, And The Timer Isn't Running,
; Update The Display.
;
SWT3 jb TMRRUN,SWT4 ; If Timer Running, It Updated Display
clr a ; Clear For Operation
mov c,LBSTAT ; Get Low Battery Status
mov acc.0,c ; Move To Acc
mov c,LOW_BAT ; Compare To Current Input Status
addc a,#0 ; Acc Will Be 0 (No Change) 1 (Change) 2 (NC)
cjne a,#1,SWT4 ; If Not Change, Don't Update Display
acall DSPDIG ; Display Timer
mov c,LOW_BAT ; Get Low Battery Input
mov LBSTAT,c ; Store Into Low Battery Status
;
; Determine If A Button Has Been Pressed
;
SWT4 clr a ; Clear For Load
mov c,SWT_GO ; Get GO Switch
mov POS_GO,c ; Move Into Acc.0
mov c,SWT_SET ; Get SET Switch
mov POS_SET,c ; Move Into Acc.1
cjne a,#003h,SWT5 ; If Not 03, Switch Changing
clr MODESWT ; No Switches Being Pressed
sjmp SWT6 ; Return
;
SWT5 mov PWRTMR,#PUPTIM ; Pressing Buttons Sets The Long Duration Timer
jb MODESWT,SWT6 ; If Switch Already Being Pressed, Skip
jb MODESPG,SWT6 ; If Last Switch Not Read, Discard This One
xrl a,#00000011b ; Make Positive Logic
mov SWTSTAT,a ; Store Switch Reading
setb MODESWT ; Set Switch Status As Being Pressed
setb MODESPG ; Say This Is A Fresh Switch Reading
;
; Recover Processor State, Return To Interruptee
;
SWT6 pop acc ; Recover Acc
pop psw ; Recover PSW
reti ; Return From Interrupt
page
;
;----------------------------------------------------------------------------
;
; SETDEC - Decrement The Minutes Portion Of The Timer. This Is Called When
; The SET Switch Is Bumped. Counter Starts At 10 Minutes, Goes
; Down To 1. Going Below 1 Wraps Back To 10.
;
SETDEC mov a,TIMMIN ; Get Minutes
jz SET1 ; If Already 0, Just Reset
dec a ; Subtract 1
mov TIMMIN,a ; Store It Back
jnz SET2 ; If Not 0, Skip
SET1 mov TIMMIN,#DEFMIN ; Else, Reset To Default Minutes
SET2 ret ; Return To Caller
page
;
;----------------------------------------------------------------------------
;
; DECTIME - Decrement The Time In The TIMSEC And TIMMI Variables. If The
; Value Underflows, Set The TMRDONE Flag. Otherwise, Return.
;
DECTIME mov a,TIMSEC ; Get Seconds
dec a ; Subtract 1
mov TIMSEC,a ; Store It Back
cjne a,#-1,DEC1 ; If No Underflow, Exit
mov TIMSEC,#59 ; Reset Seconds To 59
mov a,TIMMIN ; Get Minutes
dec a ; Subtract 1
mov TIMMIN,a ; Store It Back
;
DEC1 acall CHKZERO ; See If Time At 0 Minutes, 0 Seconds
jnz DEC2 ; If Not 0:00, Don't Mark As Done
clr TMRRUN ; Timer Not Running
setb TMRDONE ; Set The Timer Done Flag
mov PWRTMR,#PDNTIM ; Set Short Power Off Time
DEC2 ret ; Return To Caller
page
;
;----------------------------------------------------------------------------
;
; CHKHORN - See If It's One Of Those Times When We Need To Sound The Horn.
; This Occurs At 5:00 And 1:00 (Horn On For 1 Full Second), Then
; At 0:10 ... 0:01 (Horn On For 500 Milliseconds). Minutes Table
; Supports To 19 Minutes In Case We Ever Go That High (Max Display
; Range Of LCD)
;
CHKHORN mov a,TIMMIN ; Get Minutes
mov dptr,#CHKTAB ; Point To Base Of Table
movc a,@a+dptr ; Get Table Entry
jb acc.7,CHKH1 ; If Bit 7 Set, Must Be A Minute Warning
jb acc.6,CHKH3 ; If Bit 6 Set, Need To Only Test Seconds
ret ; Otherwise, Nothing Doing...
;
CHKH1 mov a,TIMSEC ; Get Seconds
jnz CHKH2 ; If Not Even Minute, No Noise
mov HRNTMR,#HRNWRN ; Store Warning Duration
setb HRNSND ; Enable Horn
CHKH2 ret ; Return To Caller
;
CHKH3 mov a,TIMSEC ; Get Seconds
jz CHKH5 ; If 0 Seconds, No Horn Chirp
cjne a,#11,CHKH4 ; Compare To 11
CHKH4 jnc CHKH5 ; If Greater Than 10 Seconds, Skip
mov HRNTMR,#HRNLTS ; Last 10 Seconds Chirp
setb HRNSND ; Enable Horn
CHKH5 ret ; Return To Caller
;
CHKTAB db 01000000b ; 0 Minutes, Check Seconds
db 10000000b ; 1 Minutes, Chirp At 1:00
db 00000000b ; 2 Minutes, No Noise
db 00000000b ; 3 Minutes, No Noise
db 00000000b ; 4 Minutes, No Noise
db 10000000b ; 5 Minutes, Chirp At 5:00
db 00000000b ; 6 Minutes, No Noise
db 00000000b ; 7 Minutes, No Noise
db 00000000b ; 8 Minutes, No Noise
db 00000000b ; 9 Minutes, No Noise
db 00000000b ; 10 Minutes, No Noise
db 00000000b ; 11 Minutes, No Noise
db 00000000b ; 12 Minutes, No Noise
db 00000000b ; 13 Minutes, No Noise
db 00000000b ; 14 Minutes, No Noise
db 00000000b ; 15 Minutes, No Noise
db 00000000b ; 16 Minutes, No Noise
db 00000000b ; 17 Minutes, No Noise
db 00000000b ; 18 Minutes, No Noise
db 00000000b ; 19 Minutes, No Noise
page
;
;----------------------------------------------------------------------------
;
; CHKZERO - Check To See If The Timer Is At 0 Minutes, 0 Seconds
;
CHKZERO mov a,TIMMIN ; Get The Minutes
orl a,TIMSEC ; OR In The Seconds
ret ; Return To Caller
;
;----------------------------------------------------------------------------
;
; DSPDIG - Display The Minutes And Seconds To The LCD Display.
;
DSPDIG mov a,TIMSEC ; Get Seconds
mov b,#10 ; Divide By 10
div ab ; Do The Divide
mov a,b ; Get Low Part
orl a,#DIGIT0 ; Select Digit 0
acall WRTDIG ; Write It
;
mov a,TIMSEC ; Get SEconds
mov b,#10 ; Divide By 10
div ab ; Do The Divide
orl a,#DIGIT1 ; Select Digit 1
acall WRTDIG ; Write It
;
mov a,TIMMIN ; Get Minutes
mov b,#10 ; Divide By 10
div ab ; Do The Divide
mov a,b ; Get Low Part
orl a,#DIGIT2 ; Select Digit 2
acall WRTDIG ; Write It
;
mov a,TIMMIN ; Get Minutes
mov b,#10 ; Divide By 10
div ab ; Do The Divide
mov c,LOW_BAT ; Get Low Battery Indicator
mov acc.1,c ; Set Into C
anl a,#00000011b ; Redundant, But VERY Safe
mov dptr,#CNVTAB ; Point To Conversion Table
movc a,@a+dptr ; Get Conversion Value
orl a,#DIGIT3 ; Select Digit 3
acall WRTDIG ; Write It
ret ; Return To Caller
;
CNVTAB db 004h ; Colon + LOBAT
db 000h ; Colon + 1 + LOBAT
db 001h ; Colon
db 007h ; Colon + 1
page
;
;----------------------------------------------------------------------------
;
; WRTDIG - Write Digit. Low 4 Bits Of Acc Has Digit To Display, Top 4
; Bits Are The Digit Number. Digit 0 Is The Left Most Digit.
;
WRTDIG mov c,acc.6 ; Get Low Order Bit Of Digit Select
mov DS1,c ; Set To LCD Controller
mov c,acc.7 ; Get High Order Bit Of Digit Select
mov DS2,c ; Set To LCD Controller
mov c,acc.0 ; Get Bit 0 Of Data
mov DATA0,c ; Set To LCD Controller
mov c,acc.1 ; Get Bit 1 Of Data
mov DATA1,c ; Set To LCD Controller
mov c,acc.2 ; Get Bit 2 Of Data
mov DATA2,c ; Set To LCD Controller
mov c,acc.3 ; Get Bit 3 Of Data
mov DATA3,c ; Set To LCD Controller
clr LCDCS ; Drive Chip Select Low To Strobe
setb LCDCS ; Bring Back High
ret ; Return To Caller
page
;
;----------------------------------------------------------------------------
;
; PTINIT - Set Chip Enables, Etc
;
PTINIT setb CPU_ON ; Make Sure We Stay Awake
setb LCDCS ; No Chip Select To LCD Controller
setb SWT_GO ; Make GO Switch An Input
setb SWT_SET ; Make SET Switch An Input
setb LOW_BAT ; Make Low Battery An Input
ret ; Return To Caller
page
;
;----------------------------------------------------------------------------
;
; E0INIT - Initialize External Interrupt 0 Sub-System
;
E0INIT clr ex0 ; No External Interrupt
ret ; Return To Caller
page
;
;----------------------------------------------------------------------------
;
; E1INIT - Initialize External Interrupt 1 Sub-System
;
E1INIT clr ex1 ; No External Interrupt
ret ; Return To Caller
page
;
;----------------------------------------------------------------------------
;
; ICINIT - Initialize I2C Bus Interface Sub-System
;
ICINIT clr i2ine ; Make Sure No I2C Interrupts Occur
ret ; Return To Caller
;
;----------------------------------------------------------------------------
;
; SWINIT - Initialize The Switch Buttons
;
SWINIT clr MODESPG ; No Buttons Pressed
clr MODESWT ; No Switches Currently Pressed
mov SECELP,#ELPTIM ; Setup Second Elapsed Counter
ret ; Return To Caller
page
;
;----------------------------------------------------------------------------
;
; PWINIT - Initalize Power Timer
;
PWINIT clr PWROFF ; Don't Power Off
mov PWRTMR,#PUPTIM ; Long Duration Time To Remain On
ret ; Return To Caller
page
;
;----------------------------------------------------------------------------
;
; HNINIT - Turn Horn Off,
;
HNINIT clr HORN ; Enable Horn
setb HRNSND ; Don't Sound Horn
mov HRNTMR,#HRNPON ; Turn
ret ; Return To Caller
page
;
;----------------------------------------------------------------------------
;
; TMINIT - Make Sure Timer Running Bit (TMRRUN) Is Cleared, Along With The
; Timer Done Status Bit (TMRDONE).
;
TMINIT clr TMRRUN ; Timer Not Running In ISR
clr TMRDONE ; Timer Not Done
ret ; Return To Caller
page
;
;----------------------------------------------------------------------------
;
; LBINIT - Initialize Low Battery Status. Make Sure Flags Different So
; At Least One Update Takes Place.
;
LBINIT mov c,LOW_BAT ; Get Low Battery Status
cpl c ; Switch States
mov LBSTAT,c ; Store Into Low Battery Status
ret ; Return To Caller
page
;
;----------------------------------------------------------------------------
;
; T0INIT - Initialize Timer 0 Sub-System
;
T0INIT mov tcon,#00000000b ; Gate=0, C/T=0, TR=0, IT0, IT1 Level Sensitive
;
if P87C751
mov a,#low (TMRRATE); Get Low Of Interrupt Time
mov tlr,a ; Set Timer Reload Value Low
mov tl,a ; Set Timer Value Low
mov a,#high (TMRRATE); Get High Of Interrupt Time
mov thr,a ; Set Timer Reload Value High
mov th,a ; Set Timer Value High
;
else
;
mov a,tmod ; Get TMOD status
anl a,#0f0h ; Don't Change Timer 1 Bits
orl a,#001h ; Set 16 Bit Timer/Counter
mov tmod,a ; Store To Real TMOD Register
mov a,#low (TMRRATE); Get Low Of Interrupt Time
mov tl0,a ; Set Timer Reload Value Low
mov a,#high (TMRRATE); Get High Of Interrupt Time
mov th0,a ; Set Timer Reload Value High
endif
;
setb et0 ; Allow Timer Overflow Interrupts
setb tr0 ; Start Timer Running
ret ; Return To Caller
page
;
;----------------------------------------------------------------------------
;
; T1INIT - Initialize Timer 1 Sub-System
;
T1INIT clr et1 ; No Interrupt From Fixed Timer 1
ret ; Return To Caller
page
end
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