AT90CAN64 Atmel Corporation, AT90CAN64 Datasheet - Page 230

• Manufacturer Part Number: AT90CAN64
• Manufacturer: Atmel Corporation

Specifications of AT90CAN64

• Flash (kbytes): 64 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 8
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 2
• Can: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 8
• Input Capture Channels: 2
• Pwm Channels: 7
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Figure 18-18. Formats and States in the Slave Transmitter Mode
18.8.5
Table 18-7.
230
Status Code
(TWSR)
Prescaler Bits
are 0
0xF8
0x00
Reception of the
own slave address
and one or
more data bytes
Arbitration lost as master
and addressed as slave
Last data byte transmitted.
Switched to not addressed
slave (TWEA = ’0’)
AT90CAN32/64/128
Miscellaneous States
Status of the Two-wire Serial Bus
and Two-wire Serial Interface
Hardware
No relevant state information
available; TWINT = “0”
Bus error due to an illegal START
or STOP condition
Miscellaneous States
From master to slave
From slave to master
S
There are two status codes that do not correspond to a defined TWI state, see
Status 0xF8 indicates that no relevant information is available because the TWINT flag is not
set. This occurs between other states, and when the TWI is not involved in a serial transfer.
Status 0x00 indicates that a bus error has occurred during a Two-wire Serial Bus transfer. A bus
error occurs when a START or STOP condition occurs at an illegal position in the format frame.
Examples of such illegal positions are during the serial transfer of an address byte, a data byte,
or an acknowledge bit. When a bus error occurs, TWINT is set. To recover from a bus error, the
TWSTO flag must set and TWINT must be cleared by writing a logic one to it. This causes the
TWI to enter the not addressed slave mode and to clear the TWSTO flag (no other bits in TWCR
are affected). The SDA and SCL lines are released, and no STOP condition is transmitted.
SLA
To/from TWDR
No TWDR action
No TWDR action
R
DATA
Application Software Response
0xA8
0xB0
A
A
n
To TWCR
STA
No TWCR action
0
A
STO
1
DATA
Any number of data bytes
and their associated acknowledge bits
This number (contained in TWSR) corresponds
to a defined state of the Two-wire Serial Bus. The
prescaler bits are zero or masked to zero
TWINT
1
TWEA
X
0xB8
A
is sent on the bus. In all cases, the bus is released and
TWSTO is cleared.
Wait or proceed current transfer
Only the internal hardware is affected, no STOP condition
DATA
Next Action Taken by TWI Hardware
0xC0
0xC8
A
A
P or S
All 1’s
Table
7679H–CAN–08/08
P or S
18-7.