ATMEGA8HVA-4TU Atmel, ATMEGA8HVA-4TU Datasheet - Page 89

• Manufacturer Part Number: ATMEGA8HVA-4TU
• Description: MCU AVR 8K FLASH 4MHZ 28-TSOP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8HVA-4TU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: SPI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 7
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 9 V
• Data Converters: A/D 5x12b
• Oscillator Type: External
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 28-TSOP
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32ATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

17.9.1
8024A–AVR–04/08
Reusing the temporary high byte register
The following code examples show how to do an atomic write of the TCNTnH/L register con-
tents. Writing any of the OCRnB/A 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 TCNTnH/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
TIMn_WriteTCNTn:
C Code Example
void TIMn_WriteTCNTn( unsigned int i )
{
}
; 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
unsigned char sreg;
unsigned int i;
/* Save global interrupt flag */
sreg = SREG;
/* Disable interrupts */
_CLI();
/* Set TCNTn to i */
TCNTn = i;
/* Restore global interrupt flag */
SREG = sreg;
See “About Code Examples” on page 7.
ATmega8HVA/16HVA
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