Rainbow-electronics ATmega103L Manuel d'utilisateur télécharger pdf (Page 45)

ATmega603/103

If the noise canceler function is enabled, the actual trigger condition for the capture event is monitored over 4 samples, and

all 4 must be equal to activate the capture flag.

Timer/Counter1 Control Register A - TCCR1A

•

Bits 7..6 - COM1A1, COM1A0: Compare Output Mode1A, bits 1 and 0

The COM1A1 and COM1A0 control bits determine any output pin action following a compare match in Timer/Counter1.

Any output pin actions affect pin OC1A - Output CompareA pin 1. This is an alternative function to an I/O port, and the cor-

responding direction control bit must be set (one) to control an output pin. The control configuration is shown in Table 16..

•

Bits 5..4 - COM1B1, COM1B0: Compare Output Mode1B, bits 1 and 0

The COM1B1 and COM1B0 control bits determine any output pin action following a compare match in Timer/Counter1.

Any output pin actions affect pin OC1B - Output CompareB. Since this is an alternative function to an I/O port, the corre-

sponding direction control bit must be set (one) to control an output pin. The following control configuration is given:

Note: X = A or B.

In PWM mode, these bits have a different function. Refer to Table 17 for a detailed description.

• Bits 3..2 - Res: Reserved bits

These bits are reserved bits in the ATmega603/103 and always read zero.

•

Bits 1..0 - PWM11, PWM10: Pulse Width Modulator Select Bits

These bits select PWM operation of Timer/Counter1 as specified in Table 19. This mode is described on page 49.

Bit 7 6 5 4 3 2 1 0

$2F ($4F) COM1A1 COM1A0 COM1B1 COM1B0 - - PWM11 PWM10 TCCR1A

Read/Write R/W R/W R/W R/W R R R/W R/W

Initial value 0 0 0 0 0 0 0 0

Table 16. Compare 1 Mode Select

COM1X1 COM1X0 Description

0 0 Timer/Counter1 disconnected from output pin OC1X

0 1 Toggle the OC1X output line.

1 0 Clear the OC1X output line (to zero).

1 1 Set the OC1X output line (to one).

Table 17. PWM Mode Select

PWM11 PWM10 Description

0 0 PWM operation of Timer/Counter1 is disabled

0 1 Timer/Counter1 is an 8-bit PWM

1 0 Timer/Counter1 is a 9-bit PWM

1 1 Timer/Counter1 is a 10-bit PWM

1 2 ... 40 41 42 43 44 45 46 47 48 49 50 ... 125 126

Pas de commentaire

Rainbow-electronics ATmega103L Manuel d'utilisateur Page 45