ATMEGA88PA-CCU Atmel, ATMEGA88PA-CCU Datasheet - Page 35

• Manufacturer Part Number: ATMEGA88PA-CCU
• Description: IC MCU AVR 8K FLASH 32VQFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA88PA-CCU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 23
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VFQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.9
8.10
8271C–AVR–08/10
Clock Output Buffer
Timer/Counter Oscillator
Figure 8-4.
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in
Table
Table 8-16.
When applying an external clock, it is required to avoid sudden changes in the applied clock fre-
quency to ensure stable operation of the MCU. A variation in frequency of more than 2% from
one clock cycle to the next can lead to unpredictable behavior. If changes of more than 2% is
required, ensure that the MCU is kept in Reset during the changes.
Note that the System Clock Prescaler can be used to implement run-time changes of the internal
clock frequency while still ensuring stable operation. Refer to
36
The device can output the system clock on the CLKO pin. To enable the output, the CKOUT
Fuse has to be programmed. This mode is suitable when the chip clock is used to drive other cir-
cuits on the system. The clock also will be output during reset, and the normal operation of I/O
pin will be overridden when the fuse is programmed. Any clock source, including the internal RC
Oscillator, can be selected when the clock is output on CLKO. If the System Clock Prescaler is
used, it is the divided system clock that is output.
ATmega48A/48PA/88A/88PA/168A/168PA/328/328P uses the same crystal oscillator for Low-
frequency Oscillator and Timer/Counter Oscillator. See
page 32
ATmega48A/48PA/88A/88PA/168A/168PA/328/328P share the Timer/Counter Oscillator Pins
(TOSC1 and TOSC2) with XTAL1 and XTAL2. When using the Timer/Counter Oscillator, the
system clock needs to be four times the oscillator frequency. Due to this and the pin sharing, the
ATmega48A/48PA/88A/88PA/168A/168PA/328/328
BOD enabled
Fast rising power
Slowly rising power
for details.
Power Conditions
8-16.
for details on the oscillator and crystal requirements.
External Clock Drive Configuration
Start-up Times for the External Clock Selection
EXTERNAL
SIGNAL
CLOCK
Start-up Time from Power-
down and Power-save
PB7
Reserved
6 CK
6 CK
6 CK
XTAL2
XTAL1
GND
”Low Frequency Crystal Oscillator” on
Additional Delay from
”System Clock Prescaler” on page
Reset (V
14CK + 4.1 ms
14CK + 65 ms
14CK
CC
= 5.0V)
SUT1...0
00
01
10
11
35