ATMEGA1284P-AU Atmel, ATMEGA1284P-AU Datasheet - Page 222
![MCU AVR 128K ISP FLASH 44-TQFP](/photos/6/70/67042/313-44-tqfp_sml.jpg)
ATMEGA1284P-AU
Manufacturer Part Number
ATMEGA1284P-AU
Description
MCU AVR 128K ISP FLASH 44-TQFP
Manufacturer
Atmel
Series
AVR® ATmegar
Datasheets
1.ATMEGA644PA-PU.pdf
(581 pages)
2.ATMEGA644PA-PU.pdf
(32 pages)
3.ATMEGA1284PR231-AU.pdf
(380 pages)
Specifications of ATMEGA1284P-AU
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
128KB (64K x 16)
Program Memory Type
FLASH
Eeprom Size
4K x 8
Ram Size
16K 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-TQFP, 44-VQFP
Processor Series
ATMEGA128x
Core
AVR8
Data Bus Width
8 bit
Data Ram Size
16 KB
Interface Type
2-Wire, SPI, USART
Maximum Clock Frequency
20 MHz
Number Of Programmable I/os
32
Number Of Timers
3
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
3rd Party Development Tools
EWAVR, EWAVR-BL
Development Tools By Supplier
ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT, ATAVRRAVEN, ATAVRRZUSBSTICK
Minimum Operating Temperature
- 40 C
On-chip Adc
10 bit, 8 Channel
Package
44TQFP
Device Core
AVR
Family Name
ATmega
Maximum Speed
20 MHz
Operating Supply Voltage
2.5|3.3|5 V
Data Rom Size
4 KB
Height
1.05 mm
Length
10.1 mm
Supply Voltage (max)
5.5 V
Supply Voltage (min)
1.8 V
Width
10.1 mm
Controller Family/series
AVR MEGA
No. Of I/o's
32
Eeprom Memory Size
4KB
Ram Memory Size
16KB
Cpu Speed
20MHz
Rohs Compliant
Yes
For Use With
ATSTK600-TQFP44 - STK600 SOCKET/ADAPTER 44-TQFPATSTK600 - DEV KIT FOR AVR/AVR32
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
ATMEGA1284P-AU
Manufacturer:
ATMEL
Quantity:
1 000
Company:
Part Number:
ATMEGA1284P-AU
Manufacturer:
ATMEL
Quantity:
748
Part Number:
ATMEGA1284P-AU
Manufacturer:
MICROCHIP/微芯
Quantity:
20 000
8059D–AVR–11/09
Figure 19-13. Data Transfer in Master Receiver Mode
A START condition is sent by writing the following value to TWCR:
TWEN must be written to one to enable the 2-wire Serial Interface, TWSTA must be written to
one to transmit a START condition and TWINT must be set to clear the TWINT Flag. The TWI
will then test the 2-wire Serial Bus and generate a START condition as soon as the bus
becomes free. After a START condition has been transmitted, the TWINT Flag is set by hard-
ware, and the status code in TWSR will be 0x08 (See
MR mode, SLA+R must be transmitted. This is done by writing SLA+R to TWDR. Thereafter the
TWINT bit should be cleared (by writing it to one) to continue the transfer. This is accomplished
by writing the following value to TWCR:
When SLA+R have been transmitted and an acknowledgement bit has been received, TWINT is
set again and a number of status codes in TWSR are possible. Possible status codes in Master
mode are 0x38, 0x40, or 0x48. The appropriate action to be taken for each of these status codes
is detailed in
when the TWINT Flag is set high by hardware. This scheme is repeated until the last byte has
been received. After the last byte has been received, the MR should inform the ST by sending a
NACK after the last received data byte. The transfer is ended by generating a STOP condition or
a repeated START condition. A STOP condition is generated by writing the following value to
TWCR:
A REPEATED START condition is generated by writing the following value to TWCR:
After a repeated START condition (state 0x10) the 2-wire Serial Interface can access the same
Slave again, or a new Slave without transmitting a STOP condition. Repeated START enables
TWCR
value
TWCR
value
TWCR
value
TWCR
value
SDA
SCL
Table 19-3 on page
TWINT
TWINT
TWINT
TWINT
1
1
1
1
Device 1
RECEIVER
MASTER
TWEA
TWEA
TWEA
TWEA
X
X
X
X
TRANSMITTER
Device 2
SLAVE
TWSTA
TWSTA
TWSTA
TWSTA
223. Received data can be read from the TWDR Register
0
1
0
1
Device 3
TWSTO
TWSTO
TWSTO
TWSTO
0
0
1
0
........
Table 19-2 on page
TWWC
TWWC
TWWC
TWWC
Device n
X
X
X
X
V
CC
TWEN
TWEN
TWEN
TWEN
ATmega1284P
1
1
1
1
R1
220). In order to enter
R2
–
0
–
0
–
0
–
0
TWIE
TWIE
TWIE
TWIE
X
X
X
X
222