ATMEGA169 ATMEL [ATMEL Corporation], ATMEGA169 Datasheet - Page 99

• Manufacturer Part Number: ATMEGA169
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

2514P–AVR–07/06
The following code examples show how to do an atomic read of the TCNT1 Register
contents. Reading any of the OCR1A/B or ICR1 Registers can be done by using the
same principle.
Note:
The assembly code example returns the TCNT1 value in the r17:r16 register pair.
Assembly Code Example
C Code Example
TIM16_ReadTCNT1:
unsigned int TIM16_ReadTCNT1( void )
{
}
; Save global interrupt flag
in
; Disable interrupts
cli
; Read TCNT1 into r17:r16
in
in
; Restore global interrupt flag
out SREG,r18
ret
unsigned char sreg;
unsigned int i;
/* Save global interrupt flag */
sreg = SREG;
/* Disable interrupts */
__disable_interrupt();
/* Read TCNT1 into i */
i = TCNT1;
/* Restore global interrupt flag */
SREG = sreg;
return i;
1. See “About Code Examples” on page 6.
r18,SREG
r16,TCNT1L
r17,TCNT1H
(1)
(1)
ATmega169/V
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