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registers, Figure 39), Preliminary – Rainbow Electronics T89C51CC02 User Manual

Page 55: Registers

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Rev.A - May 17, 2001

55

Preliminary

T89C51CC02

12.6. Registers

TCON (S:88h)
Timer/Counter Control Register.

Reset Value= 0000 0000b

Figure 39. TCON Register

7

6

5

4

3

2

1

0

TF1

TR1

TF0

TR0

IE1

IT1

IE0

IT0

Bit Number Bit Mnemonic

Description

7

TF1

Timer 1 Overflow Flag

Cleared by hardware when processor vectors to interrupt routine.
Set by hardware on Timer/Counter overflow, when Timer 1 register overflows.

6

TR1

Timer 1 Run Control Bit

Clear to turn off Timer/Counter 1.
Set to turn on Timer/Counter 1.

5

TF0

Timer 0 Overflow Flag

Cleared by hardware when processor vectors to interrupt routine.
Set by hardware on Timer/Counter overflow, when Timer 0 register overflows.

4

TR0

Timer 0 Run Control Bit

Clear to turn off Timer/Counter 0.
Set to turn on Timer/Counter 0.

3

IE1

Interrupt 1 Edge Flag

Cleared by hardware when interrupt is processed if edge-triggered (see IT1).
Set by hardware when external interrupt is detected on INT1# pin.

2

IT1

Interrupt 1 Type Control Bit

Clear to select low level active (level triggered) for external interrupt 1 (INT1#).
Set to select falling edge active (edge triggered) for external interrupt 1.

1

IE0

Interrupt 0 Edge Flag

Cleared by hardware when interrupt is processed if edge-triggered (see IT0).
Set by hardware when external interrupt is detected on INT0# pin.

0

IT0

Interrupt 0 Type Control Bit

Clear to select low level active (level triggered) for external interrupt 0 (INT0#).
Set to select falling edge active (edge triggered) for external interrupt 0.