AT90CAN32 Automotive Atmel Corporation, AT90CAN32 Automotive Datasheet - Page 183

• Manufacturer Part Number: AT90CAN32 Automotive
• Manufacturer: Atmel Corporation

Specifications of AT90CAN32 Automotive

• Flash (kbytes): 32 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): 2
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 125
• 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

17.7.1
7682C–AUTO–04/08
Sending Frames with 5 to 8 Data Bit
chronous operation is used, the clock on the XCKn pin will be overridden and used as
transmission clock.
A data transmission is initiated by loading the transmit buffer with the data to be transmitted. The
CPU can load the transmit buffer by writing to the UDRn I/O location. The buffered data in the
transmit buffer will be moved to the Shift Register when the Shift Register is ready to send a new
frame. The Shift Register is loaded with new data if it is in idle state (no ongoing transmission) or
immediately after the last stop bit of the previous frame is transmitted. When the Shift Register is
loaded with new data, it will transfer one complete frame at the rate given by the Baud Register,
U2Xn bit or by XCKn depending on mode of operation.
The following code examples show a simple USART0 transmit function based on polling of the
Data Register Empty (UDRE0) flag. When using frames with less than eight bits, the most signif-
icant bits written to the UDR0 are ignored. The USART0 has to be initialized before the function
can be used. For the assembly code, the data to be sent is assumed to be stored in Register
R16
Note:
The function simply waits for the transmit buffer to be empty by checking the UDRE0 flag, before
loading it with new data to be transmitted. If the Data Register Empty interrupt is utilized, the
interrupt routine writes the data into the buffer.
Assembly Code Example
C Code Example
.
USART0_Transmit:
void USART0_Transmit (unsigned char data)
{
}
; Wait for empty transmit buffer
lds
sbrs
rjmp
; Put data (r16) into buffer, sends the data
sts
ret
/* Wait for empty transmit buffer */
while ( ! ( UCSRA0 & (1<<UDRE0)));
/* Put data into buffer, sends the data */
UDR0 = data;
1. The example code assumes that the part specific header file is included.
r17, UCSR0A
r17, UDRE0
USART0_Transmit
UDR0, r16
(1)
(1)
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