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Timer/counter0 control register – tccr0 – Rainbow Electronics AT90C8534 User Manual

Page 25

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AT90C8534

25

Figure 27. Timer/Counter0 Block Diagram

Timer/Counter0 Control Register – TCCR0

Bits 7..3 – Res: Reserved Bits

These bits are reserved bits in the AT90C8534 and always read zero.

Bits 2, 1, 0 – CS02, CS01, CS00: Clock Select0, Bits 2, 1 and 0

The Clock Select0 bits 2, 1 and 0 define the prescaling source of Timer/Counter0.

The Stop condition provides a Timer Enable/Disable function. The prescaled CK modes are scaled directly from the CK
oscillator clock.

Bit

7

6

5

4

3

2

1

0

$33 ($53)

CS02

CS01

CS00

TCCR0

Read/Write

R

R

R

R

R

R/W

R/W

R/W

Initial value

0

0

0

0

0

0

0

0

Table 4. Clock 0 Prescale Select

CS02

CS01

CS00

Description

0

0

0

Stop, Timer/Counter0 is stopped.

0

0

1

CK

0

1

0

CK/8

0

1

1

CK/64

1

0

0

CK/256

1

0

1

CK/1024

1

1

0

Reserved

1

1

1

Reserved

8-BIT DA

T

A

BUS

T/C0 CONTROL

REGISTER (TCCR0)

TIMER/COUNTER0

(TCNT0)

0

7

T/C CLK SOURCE

CONTROL

LOGIC

CS02

CS01

CS00

CK

T/C0 OVER-

FLOW IRQ

TIMER INT. MASK

REGISTER (TIMSK)

TOIE0

TOIE1

TIMER INT. FLAG

REGISTER (TIFR)

TOV0

TOV1