ATMEGA64-16MJ Atmel, ATMEGA64-16MJ Datasheet - Page 70

• Manufacturer Part Number: ATMEGA64-16MJ
• Description: IC MCU AVR 64K 5V 16MHZ 64-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA64-16MJ

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-MLF®, 64-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Digital Input Enable
and Sleep Modes
Unconnected Pins
2490Q–AVR–06/10
The following code example show how to set Port B pins 0 and 1 high, 2 and 3 low, and define
the port pins from 4 to 7 as input with pull-ups assigned to port pins 6 and 7. The resulting pin
values are read back again, but as previously discussed, a nop instruction is included to be able
to read back the value recently assigned to some of the pins.
Note:
As shown in
Schmitt Trigger. The signal denoted SLEEP in the figure, is set by the MCU Sleep Controller in
Power-down mode, Power-save mode, Standby mode, and Extended Standby mode to avoid
high power consumption if some input signals are left floating, or have an analog signal level
close to V
SLEEP is overridden for port pins enabled as External Interrupt pins. If the External Interrupt
request is not enabled, SLEEP is active also for these pins. SLEEP is also overridden by various
other alternate functions as described in
If a logic high level (“one”) is present on an asynchronous External Interrupt pin configured as
“Interrupt on Any Logic Change on Pin” while the External Interrupt is not enabled, the corre-
sponding External Interrupt Flag will be set when resuming from the above mentioned sleep
modes, as the clamping in these sleep modes produces the requested logic change.
If some pins are unused, it is recommended to ensure that these pins have a defined level. Even
though most of the digital inputs are disabled in the deep sleep modes as described above, float-
Assembly Code Example
C Code Example
unsigned char i;
...
; Define pull-ups and set outputs high
; Define directions for port pins
ldi
ldi
out
out
; Insert nop for synchronization
nop
; Read port pins
in
...
...
/* Define pull-ups and set outputs high */
/* Define directions for port pins */
PORTB = (1<<PB7)|(1<<PB6)|(1<<PB1)|(1<<PB0);
DDRB = (1<<DDB3)|(1<<DDB2)|(1<<DDB1)|(1<<DDB0);
/* Insert nop for synchronization*/
_NOP();
/* Read port pins */
i = PINB;
...
1. For the assembly program, two temporary registers are used to minimize the time from pull-
CC
ups are set on pins 0, 1, 6, and 7, until the direction bits are correctly set, defining bit 2 and 3
as low and redefining bits 0 and 1 as strong high drivers.
/2.
r16,(1<<PB7)|(1<<PB6)|(1<<PB1)|(1<<PB0)
r17,(1<<DDB3)|(1<<DDB2)|(1<<DDB1)|(1<<DDB0)
PORTB,r16
DDRB,r17
r16,PINB
Figure
30, the digital input signal can be clamped to ground at the input of the
(1)
“Alternate Port Functions” on page
ATmega64(L)
71.
70