ATMEGA32A-PU Atmel, ATMEGA32A-PU Datasheet - Page 172

• Manufacturer Part Number: ATMEGA32A-PU
• Description: MCU AVR 32K FLASH 16MHZ 40-PDIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA32A-PU

• 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: 32
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Processor Series: ATMEGA32x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: 2-Wire, SPI, USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Package: 40PDIP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 16 MHz
• Operating Supply Voltage: 3.3|5 V
• Data Rom Size: 1024 B
• Height: 4.83 mm
• Length: 52.58 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Width: 13.97 mm
• Controller Family/series: AVR MEGA
• No. Of I/o's: 32
• Eeprom Memory Size: 1KB
• Ram Memory Size: 2KB
• Cpu Speed: 16MHz
• Rohs Compliant: Yes
• For Use With: ATSTK524 - KIT STARTER ATMEGA32M1/MEGA32C1ATSTK600 - DEV KIT FOR AVR/AVR32ATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

19.12 Examples of Baud Rate Setting
Table 19-9.
8155C–AVR–02/11
Baud
Rate
(bps)
2400
4800
9600
14.4k
19.2k
28.8k
38.4k
57.6k
76.8k
115.2k
UBRR
25
12
6
3
2
1
1
0
–
–
Examples of UBRR Settings for Commonly Used Oscillator Frequencies
U2X = 0
f
-18.6%
osc
-7.0%
Error
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
–
–
= 1.0000MHz
• Bit 15 – URSEL: Register Select
This bit selects between accessing the UBRRH or the UCSRC Register. It is read as zero when
reading UBRRH. The URSEL must be zero when writing the UBRRH.
• Bit 14:12 – Reserved Bits
These bits are reserved for future use. For compatibility with future devices, these bit must be
written to zero when UBRRH is written.
• Bit 11:0 – UBRR11:0: USART Baud Rate Register
This is a 12-bit register which contains the USART baud rate. The UBRRH contains the four
most significant bits, and the UBRRL contains the 8 least significant bits of the USART baud
rate. Ongoing transmissions by the transmitter and receiver will be corrupted if the baud rate is
changed. Writing UBRRL will trigger an immediate update of the baud rate prescaler.
For standard crystal and resonator frequencies, the most commonly used baud rates for asyn-
chronous operation can be generated by using the UBRR settings in
which yield an actual baud rate differing less than 0.5% from the target baud rate, are bold in the
table. Higher error ratings are acceptable, but the receiver will have less noise resistance when
the error ratings are high, especially for large serial frames (see
Range” on page
UBRR
51
25
12
8
6
3
2
1
1
0
U2X = 1
-18.6%
-3.5%
-7.0%
Error
0.2%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
163). The error values are calculated using the following equation:
UBRR
47
23
11
7
5
3
2
1
0
1
U2X = 0
Error[%]
f
-25.0%
osc
Error
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
= 1.8432MHz
=
⎛
⎝
BaudRate
------------------------------------------------------- - 1
UBRR
95
47
23
15
11
BaudRate
7
5
3
2
1
U2X = 1
Closest Match
Error
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
–
UBRR
⎞
⎠
51
25
12
•
8
6
3
2
1
1
0
100%
U2X = 0
“Asynchronous Operational
f
-18.6%
-3.5%
-7.0%
osc
Table
Error
0.2%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
ATmega32A
= 2.0000MHz
19-9. UBRR values
UBRR
103
51
25
16
12
8
6
3
2
1
U2X = 1
-3.5%
-7.0%
Error
0.2%
0.2%
0.2%
2.1%
0.2%
8.5%
8.5%
8.5%
172