Registers – Rainbow Electronics AT89C5122 User Manual

Page 152

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152

AT8xC5122/23

4202E–SCR–06/06

Registers

Timer/Counter Control Register

Reset Value = 0000 0000b

Table 88. TCON (S:88h)

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 the hardware when processor vectors interrupt routine.
Set by the hardware 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 the hardware when processor vectors interrupt routine or by software
when the interrupt is disabled
Set by the hardware 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 the hardware when interrupt is processed if edge-triggered (see IT1).
Set by the hardware when external interrupt is detected on the 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 the hardware when interrupt is processed if edge-triggered (see IT0).
Set by the 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.

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