ATMEGA88A-MMH Atmel, ATMEGA88A-MMH Datasheet - Page 195
![IC MCU AVR 8K FLASH 28QFN](/photos/12/32/123209/28m1-vqfn_sml.jpg)
ATMEGA88A-MMH
Manufacturer Part Number
ATMEGA88A-MMH
Description
IC MCU AVR 8K FLASH 28QFN
Manufacturer
Atmel
Series
AVR® ATmegar
Specifications of ATMEGA88A-MMH
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
28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
- Current page: 195 of 566
- Download datasheet (23Mb)
19.9.1
19.10 Examples of Baud Rate Setting
8271C–AVR–08/10
Using MPCMn
setting, but has to be used differently when it is a part of a system utilizing the Multi-processor
Communication mode.
If the Receiver is set up to receive frames that contain 5 to 8 data bits, then the first stop bit indi-
cates if the frame contains data or address information. If the Receiver is set up for frames with
nine data bits, then the ninth bit (RXB8n) is used for identifying address and data frames. When
the frame type bit (the first stop or the ninth bit) is one, the frame contains an address. When the
frame type bit is zero the frame is a data frame.
The Multi-processor Communication mode enables several slave MCUs to receive data from a
master MCU. This is done by first decoding an address frame to find out which MCU has been
addressed. If a particular slave MCU has been addressed, it will receive the following data
frames as normal, while the other slave MCUs will ignore the received frames until another
address frame is received.
For an MCU to act as a master MCU, it can use a 9-bit character frame format (UCSZn = 7). The
ninth bit (TXB8n) must be set when an address frame (TXB8n = 1) or cleared when a data frame
(TXB = 0) is being transmitted. The slave MCUs must in this case be set to use a 9-bit character
frame format.
The following procedure should be used to exchange data in Multi-processor Communication
mode:
1. All Slave MCUs are in Multi-processor Communication mode (MPCMn in
2. The Master MCU sends an address frame, and all slaves receive and read this frame. In
3. Each Slave MCU reads the UDRn Register and determines if it has been selected. If so,
4. The addressed MCU will receive all data frames until a new address frame is received.
5. When the last data frame is received by the addressed MCU, the addressed MCU sets
Using any of the 5- to 8-bit character frame formats is possible, but impractical since the
Receiver must change between using n and n+1 character frame formats. This makes full-
duplex operation difficult since the Transmitter and Receiver uses the same character size set-
ting. If 5- to 8-bit character frames are used, the Transmitter must be set to use two stop bit
(USBSn = 1) since the first stop bit is used for indicating the frame type.
Do not use Read-Modify-Write instructions (SBI and CBI) to set or clear the MPCMn bit. The
MPCMn bit shares the same I/O location as the TXCn Flag and this might accidentally be
cleared when using SBI or CBI instructions.
For standard crystal and resonator frequencies, the most commonly used baud rates for asyn-
chronous operation can be generated by using the UBRRn settings in
which yield an actual baud rate differing less than 0.5% from the target baud rate, are bold in the
ATmega48A/48PA/88A/88PA/168A/168PA/328/328
UCSRnA is set).
the Slave MCUs, the RXCn Flag in UCSRnA will be set as normal.
it clears the MPCMn bit in UCSRnA, otherwise it waits for the next address byte and
keeps the MPCMn setting.
The other Slave MCUs, which still have the MPCMn bit set, will ignore the data frames.
the MPCMn bit and waits for a new address frame from master. The process then
repeats from 2.
Table
. UBRRn values
195
Related parts for ATMEGA88A-MMH
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![ATMEGA88-20AI](/photos/6/91/69154/313-32-tqfp_tmb.jpg)
Part Number:
Description:
IC MCU AVR 8K 5V 20MHZ 32-TQFP
Manufacturer:
Atmel
Datasheet:
![ATmega88](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
![ATmega88 Automotive](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
![ATMEGA88-15MZ](/photos/30/99/309943/qfn-32_tmb.jpg)
Part Number:
Description:
MCU AVR 8K FLASH 15MHZ 32-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA88-20AU](/photos/6/91/69154/313-32-tqfp_tmb.jpg)
Part Number:
Description:
IC AVR MCU 8K 20MHZ 5V 32TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA88-20MU](/images/manufacturer_photos/0/0/78/atmel_tmb.jpg)
Part Number:
Description:
IC AVR MCU 8K 20MHZ 5V 32-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA88-20PU](/photos/7/21/72189/453-28-dip_tmb.jpg)
Part Number:
Description:
IC AVR MCU 8K 20MHZ 5V 28DIP
Manufacturer:
Atmel
Datasheet:
![ATMEGA88-20AJ](/photos/6/91/69154/313-32-tqfp_tmb.jpg)
Part Number:
Description:
IC MCU AVR 8K 5V 20MHZ 32-TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA88-20MI](/images/manufacturer_photos/0/0/78/atmel_tmb.jpg)
Part Number:
Description:
IC MCU AVR 8K 5V 20MHZ 32-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA88-20MJ](/images/manufacturer_photos/0/0/78/atmel_tmb.jpg)
Part Number:
Description:
IC MCU AVR 8K 5V 20MHZ 32-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA88-20PI](/photos/7/21/72189/453-28-dip_tmb.jpg)
Part Number:
Description:
IC MCU AVR 8K 5V 20MHZ 28-DIP
Manufacturer:
Atmel
Datasheet:
![ATMEGA88-20PJ](/photos/7/21/72189/453-28-dip_tmb.jpg)
Part Number:
Description:
IC MCU AVR 8K 5V 20MHZ 28-DIP
Manufacturer:
Atmel
Datasheet:
![ATMEGA88-20AUR](/images/manufacturer_photos/0/0/78/atmel_tmb.jpg)
Part Number:
Description:
MCU AVR 8K FLASH 20MHZ 32TQFP
Manufacturer:
Atmel
Datasheet: