ATMEGA1284PR212-MU Atmel, ATMEGA1284PR212-MU Datasheet - Page 217

• Manufacturer Part Number: ATMEGA1284PR212-MU
• Description: BUNDLE ATMEGA1284P/RF212 QFN
• Manufacturer: Atmel

Specifications of ATMEGA1284PR212-MU

• Frequency: 2.4GHz
• Modulation Or Protocol: 802.15.4 Zigbee, 6LoWPAN, ISM
• Data Interface: PCB, Surface Mount
• Memory Size: 128kB Flash, 4kB EEPROM, 16kB RAM
• Antenna Connector: PCB, Surface Mount
• Package / Case: 44-QFN, 32-QFN
• Processor Series: ATMEGA128x
• Core: AVR8
• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 128 KB
• Data Ram Size: 16 KB
• Development Tools By Supplier: ATAVRRZ541, ATAVRRAVEN, ATAVRRZUSBSTICK, ATAVRISP2, ATAVRRZ201
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Power - Output: -
• Operating Temperature: -
• Applications: -
• Sensitivity: -
• Data Rate - Maximum: -
• Current - Transmitting: -
• Current - Receiving: -
• Lead Free Status / Rohs Status: Details

8059D–AVR–11/09
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Assembly Code Example
ldi
out
wait1:
in
sbrs r16,TWINT
rjmp wait1
in
andi r16, 0xF8
cpi
brne ERROR
ldi
out
ldi
out
wait2:
in
sbrs r16,TWINT
rjmp wait2
in
andi r16, 0xF8
cpi
brne ERROR
ldi
out
ldi
out
r16, (1<<TWINT)|(1<<TWSTA)|
(1<<TWEN)
TWCR, r16
r16,TWCR
r16,TWSR
r16, START
r16, SLA_W
TWDR, r16
r16, (1<<TWINT) | (1<<TWEN)
TWCR, r16
r16,TWCR
r16,TWSR
r16, MT_SLA_ACK
r16, DATA
TWDR, r16
r16, (1<<TWINT) | (1<<TWEN)
TWCR, r16
• When the TWINT Flag is set, the user must update all TWI Registers with the value relevant for
• After all TWI Register updates and other pending application software tasks have been
In the following an assembly and C implementation of the example is given. Note that the code
below assumes that several definitions have been made, for example by using include-files.
the next TWI bus cycle. As an example, TWDR must be loaded with the value to be transmitted
in the next bus cycle.
completed, TWCR is written. When writing TWCR, the TWINT bit should be set. Writing a one
to TWINT clears the flag. The TWI will then commence executing whatever operation was
specified by the TWCR setting.
C Example
TWCR = (1<<TWINT)|(1<<TWSTA)|
while (!(TWCR & (1<<TWINT)))
if ((TWSR & 0xF8) != START)
TWDR = SLA_W;
TWCR = (1<<TWINT) | (1<<TWEN); Load SLA_W into TWDR Register.
while (!(TWCR & (1<<TWINT)))
if ((TWSR & 0xF8) !=
MT_SLA_ACK)
TWDR = DATA;
TWCR = (1<<TWINT) | (1<<TWEN); Load DATA into TWDR Register.
(1<<TWEN)
;
ERROR();
;
ERROR();
Comments
Send START condition
Wait for TWINT Flag set. This
indicates that the START condition
has been transmitted
Check value of TWI Status
Register. Mask prescaler bits. If
status different from START go to
ERROR
Clear TWINT bit in TWCR to start
transmission of address
Wait for TWINT Flag set. This
indicates that the SLA+W has been
transmitted, and ACK/NACK has
been received.
Check value of TWI Status
Register. Mask prescaler bits. If
status different from MT_SLA_ACK
go to ERROR
Clear TWINT bit in TWCR to start
transmission of data
ATmega1284P
217