ATMEGA164PA-MCH Atmel, ATMEGA164PA-MCH Datasheet - Page 232
![MCU AVR 16KB FLASH 20MHZ 44-VQFN](/photos/12/13/121316/313-44-qfn_sml.jpg)
ATMEGA164PA-MCH
Manufacturer Part Number
ATMEGA164PA-MCH
Description
MCU AVR 16KB FLASH 20MHZ 44-VQFN
Manufacturer
Atmel
Series
AVR® ATmegar
Specifications of ATMEGA164PA-MCH
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
32
Program Memory Size
16KB (8K 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
44-VQFN Exposed Pad
For Use With
ATSTK600-TQFP44 - STK600 SOCKET/ADAPTER 44-TQFP
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
- Current page: 232 of 581
- Download datasheet (27Mb)
20.8
8272A–AVR–01/10
Multi-master Systems and Arbitration
Note that data is transmitted both from Master to Slave and vice versa. The Master must instruct
the Slave what location it wants to read, requiring the use of the MT mode. Subsequently, data
must be read from the Slave, implying the use of the MR mode. Thus, the transfer direction must
be changed. The Master must keep control of the bus during all these steps, and the steps
should be carried out as an atomical operation. If this principle is violated in a multimaster sys-
tem, another Master can alter the data pointer in the EEPROM between steps 2 and 3, and the
Master will read the wrong data location. Such a change in transfer direction is accomplished by
transmitting a REPEATED START between the transmission of the address byte and reception
of the data. After a REPEATED START, the Master keeps ownership of the bus. The following
figure shows the flow in this transfer.
Figure 20-19. Combining Several TWI Modes to Access a Serial EEPROM
If multiple masters are connected to the same bus, transmissions may be initiated simultane-
ously by one or more of them. The TWI standard ensures that such situations are handled in
such a way that one of the masters will be allowed to proceed with the transfer, and that no data
will be lost in the process. An example of an arbitration situation is depicted below, where two
masters are trying to transmit data to a Slave Receiver.
Figure 20-20. An Arbitration Example
Several different scenarios may arise during arbitration, as described below:
• Two or more masters are performing identical communication with the same Slave. In this
• Two or more masters are accessing the same Slave with different data or direction bit. In this
164A/164PA/324A/324PA/644A/644PA/1284/1284P
case, neither the Slave nor any of the masters will know about the bus contention.
case, arbitration will occur, either in the READ/WRITE bit or in the data bits. The masters trying
to output a one on SDA while another Master outputs a zero will lose the arbitration. Losing
masters will switch to not addressed Slave mode or wait until the bus is free and transmit a new
START condition, depending on application software action.
S
S = START
SDA
SCL
Transmitted from master to slave
SLA+W
TRANSMITTER
Device 1
MASTER
A
Master Transmitter
ADDRESS
TRANSMITTER
Device 2
MASTER
Device 3
RECEIVER
A
SLAVE
Rs = REPEATED START
Rs
Transmitted from slave to master
........
SLA+R
Device n
V
CC
A
Master Receiver
R1
DATA
R2
P = STOP
A
P
232
Related parts for ATMEGA164PA-MCH
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![atmega164-20pu](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
8-bit Microcontroller With 16/32/64k Bytes In-system Programmable Flash - Atmel Corporation
Manufacturer:
ATMEL Corporation
Datasheet:
![ATMEGA164](/images/no-image3.png)
Part Number:
Description:
8-bit Microcontroller with 16/32/64K Bytes In-System Programmable Flash
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
![ATmega16](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
![ATMEGA16-16AU](/photos/6/70/67042/313-44-tqfp_tmb.jpg)
Part Number:
Description:
IC AVR MCU 16K 16MHZ 5V 44TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA16-16MU](/photos/12/13/121316/313-44-qfn_tmb.jpg)
Part Number:
Description:
IC AVR MCU 16K 16MHZ 5V 44-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA16-16PU](/photos/6/70/67049/453-40-dip_tmb.jpg)
Part Number:
Description:
IC AVR MCU 16K 16MHZ 5V 40DIP
Manufacturer:
Atmel
Datasheet:
![ATMEGA16-16MQ](/photos/12/13/121316/313-44-qfn_tmb.jpg)
Part Number:
Description:
MCU AVR 16K FLASH 16MHZ 44-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA16-16PC](/photos/6/70/67049/453-40-dip_tmb.jpg)
Part Number:
Description:
IC AVR MCU 16K 16MHZ COM 40-DIP
Manufacturer:
Atmel
Datasheet:
![ATMEGA16-16MC](/photos/12/13/121316/313-44-qfn_tmb.jpg)
Part Number:
Description:
IC AVR MCU 16K 16MHZ COM 44-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA16-16PI](/photos/6/70/67049/453-40-dip_tmb.jpg)
Part Number:
Description:
IC AVR MCU 16K 16MHZ IND 40-DIP
Manufacturer:
Atmel
Datasheet:
![ATMEGA16-16MI](/photos/12/13/121316/313-44-qfn_tmb.jpg)
Part Number:
Description:
IC AVR MCU 16K 16MHZ IND 44-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA16-16AI](/photos/6/70/67042/313-44-tqfp_tmb.jpg)
Part Number:
Description:
IC AVR MCU 16K 16MHZ IND 44-TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA16-16AU SL383](/photos/6/70/67042/313-44-tqfp_tmb.jpg)
Part Number:
Description:
IC MCU 8BIT 16KB FLASH 44TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA16-16AQ](/photos/6/70/67042/313-44-tqfp_tmb.jpg)
Part Number:
Description:
MCU AVR 16K FLASH 16MHZ 44-TQFP
Manufacturer:
Atmel
Datasheet: