Intel MCS 51 User Manual

intel.
M=@-51 PROGRAMMER’SGUIDE AND INSTRUCTION SET
TCON: TIMER/COUNTER CONTROL REGISTER. BIT ADDRESSABLE.
TFl
TR1 TFO
TRO IE1
IT1
IEO
ITO
TFl
TR1
TFO
TRO
IEI
IT1
IEO
ITO
TCON.7 Timer 1overflowflag.Setby hardwarewhenthe Timer/Counter 1overtlows.Clearedby hsrd-
ware as processorvectorsto the interrupt serviceroutine.
TCON.6 Timer 1run controlbit. Set/ckared by softwareto turn Timer/Counter 1ON/OFF.
TCON.5 Timer Ooverflowflag.Setby hardwarewhenthe Timer/CounterOoverflows.Clearedby hsrd-
ware as proceasorvectorsto the seMce routine.
TCON.4 TixnerOrun control bit. Set/clearedby softwareto turn Timer/Counter OON/OFF.
TCON.3 External Interrupt 1 edge flag. Set by hardware when Extemsf Interrupt edge is detected.
Clearedby hardware wheninterrupt is proeesaed.
TCON.2 Interrupt 1type controlbit. Set/cleared by sotlwsre to specifyfalling edgeflowleveltriggered
ExternalInterrupt.
TCON.1 ExternalInterrupt Oedgeflag.Setby hardwarewhenExternalInterrupt edgedeteeted.Cleared
by hardware wheninterrupt is proeeased.
TCGN.O Interrupt Otype controlbit. Set/cleared by sotlwsre to specifyfsflingedge/lowleveltriggered
ExternalInterrupt.
TMOD: TIMER/COUNTER MODE CONTROL REGISTER. NOT BIT
ADDRESSABLE.
TIMER 1 TIMER O
GATE WhenTRx(inTCON)isset rmdGATE = 1,TIMEIUCOUNTERxwillrun onlywhileINTxpinishigh
(hardwareecmtrol).When GATE = O,TWIER./C0UNTERxwill run only while TRx = 1 (software
control).
CiT’
Timeror Counterseleetor.Ckred forTimeroperation(inputfrominternalsystemclock).Setfor Coun-
ter operation(input from Tx input
pin).
Ml
Modeselectorbit. (NOTE 1)
MO
Modeselectorbit. (NOTE 1)
NOTE1:
Ml MO
Operating Mode
o
00 13-bitTimer (MCSA8 compatible)
o
1
1
16-bitTimer/Counter
1
02
8-bit Auto-ReloadTimer/Counter
1
1
3
mimero).TLoisan a-bitTimer/Countercontrolledby
the standard Timero
controlbite,THOisan 8-bitTimerand is controlledbyTimer 1 controlbits.
1
1
3
(Timer 1) Timer/Counter1 stopped.
2-14

Intel MCS 51 Specifications

General

Brand	Intel
Model	MCS 51
Category	Microcontrollers
Language	English