ATTINY40-MMHR Atmel, ATTINY40-MMHR Datasheet - Page 93

• Manufacturer Part Number: ATTINY40-MMHR
• Description: MCU AVR 4KB FLASH 12MHZ 3X3 QFN
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY40-MMHR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 12MHz
• Connectivity: I²C, SPI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 18
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

12.9.1
8263A–AVR–08/10
Reusing the temporary high byte register
The following code examples show how to do an atomic write of the TCNT1H/L register con-
tents. Writing any of the OCR1A/B registers can be done by using the same principle.
Note:
The assembly code example requires that the r17:r16 register pair contains the value to be writ-
ten to TCNT1H/L.
If writing to more than one 16-bit register where the high byte is the same for all registers written,
then the high byte only needs to be written once. However, note that the same rule of atomic
operation described previously also applies in this case.
Assembly Code Example
TIM1_WriteTCNT1:
C Code Example
void TIM1_WriteTCNT1( unsigned int i )
{
}
; Save global interrupt flag
in r18,SREG
; Disable interrupts
cli
; Set TCNT
out TCNT1H,r17
out TCNT1L,r16
; Restore global interrupt flag
out SREG,r18
ret
unsigned char sreg;
/* Save global interrupt flag */
sreg = SREG;
/* Disable interrupts */
_CLI();
/* Set TCNT1 to i */
TCNT1H = (i >> 8);
TCNT1L = (unsigned char)i;
/* Restore global interrupt flag */
SREG = sreg;
See
“Code Examples” on page
1
to r17:r16
6.
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