Datasheet

Assembly Code Example
(1)
TIM16_ReadTCNTn:
; Save global interrupt flag
in r18,SREG
; Disable interrupts
cli
; Read TCNTn into r17:r16
in r16,TCNTnL
in r17,TCNTnH
; Restore global interrupt flag
out SREG,r18
ret
The assembly code example returns the TCNTn value in the r17:r16 register pair.
C Code Example
(1)
unsigned int TIM16_ReadTCNTn( void )
{
unsigned char sreg;
unsigned int i;
/* Save global interrupt flag */
sreg = SREG;
/* Disable interrupts */
_CLI();
/* Read TCNTn into i */
i = TCNTn;
/* Restore global interrupt flag */
SREG = sreg;
return i;
}
Note:
1. The example code assumes that the part specific header file is included. For I/O registers located in
extended I/O map, “IN”, “OUT”, “SBIS”, “SBIC”, “CBI”, and “SBI” instructions must be replaced with
instructions that allow access to extended I/O. Typically “LDS” and “STS” combined with “SBRS”,
“SBRC”, “SBR”, and “CBR”.
Atomic Write
The following code examples show how to do an atomic write of the TCNTn register contents. Writing any
of the OCRnA/B or ICRn registers can be done by using the same principle.
Assembly Code Example
(1)
TIM16_WriteTCNTn:
; Save global interrupt flag
in r18,SREG
; Disable interrupts
cli
; Set TCNTn to r17:r16
out TCNTnH,r17
out TCNTnL,r16
; Restore global interrupt flag
out SREG,r18
ret
The assembly code example requires that the r17:r16 register pair contains the value to
be written to TCNTn.
C Code Example
(1)
void TIM16_WriteTCNTn( unsigned int i )
{
ATmega328PB
TC1, 3, 4 - 16-bit Timer/Counter1, 3, 4 with PWM
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001906C-page 161