ATMEGA8515L-8MU Atmel, ATMEGA8515L-8MU Datasheet - Page 63

• Manufacturer Part Number: ATMEGA8515L-8MU
• Description: IC AVR MCU 8K 8MHZ 3V 44-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8515L-8MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: EBI/EMI, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 35
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-VQFN Exposed Pad
• Processor Series: ATMEGA8x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: SPI, USART
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 35
• Number Of Timers: 2
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Minimum Operating Temperature: - 40 C
• For Use With: ATAVRISP2 - PROGRAMMER AVR IN SYSTEMATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Details

Digital Input Enable and Sleep
Modes
2512K–AVR–01/10
The following code example shows 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 Figure 30, the digital input signal can be clamped to ground at the input of
the Schmitt Trigger. The signal denoted SLEEP in the figure, is set by the MCU Sleep
Controller in Power-down mode and 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 “Alternate Port Func-
tions” on page 64.
If a logic high level (“one”) is present on an Asynchronous External Interrupt pin config-
ured as “Interrupt on Rising Edge, Falling Edge, or Any Logic Change on Pin” while the
external interrupt is not enabled, the corresponding 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.
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-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.
r16,(1<<PB7)|(1<<PB6)|(1<<PB1)|(1<<PB0)
r17,(1<<DDB3)|(1<<DDB2)|(1<<DDB1)|(1<<DDB0)
PORTB,r16
DDRB,r17
r16,PINB
(1)
ATmega8515(L)
CC
/2.
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