ATMEGA8HVD-4MX Atmel, ATMEGA8HVD-4MX Datasheet - Page 85

• Manufacturer Part Number: ATMEGA8HVD-4MX
• Description: MCU AVR 8K FLASH 2.1-8V 4MHZ QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8HVD-4MX

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 4MHz
• Peripherals: POR, WDT
• Number Of I /o: 5
• 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): 2 V ~ 2.4 V
• Data Converters: A/D 1x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 18-MLF® Exposed Pad (Staggered Leads), DFN
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32ATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Connectivity: -

16.9.1
8052B–AVR–09/08
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 OCRnA/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
written to TCNTnH/L.
If writing to more than one 16-bit register where the high byte is the same for all registers writ-
ten, 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
5.
ATmega4HVD/8HVD
85