SAM7SE256 Atmel Corporation, SAM7SE256 Datasheet - Page 303

• Manufacturer Part Number: SAM7SE256
• Manufacturer: Atmel Corporation

Specifications of SAM7SE256

• Flash (kbytes): 256 Kbytes
• Pin Count: 144
• Max. Operating Frequency: 48 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 88
• Ext Interrupts: 88
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 1
• Uart: 3
• Ssc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 32
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: sdram
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

30.4.2.3
30.4.2.4
30.4.2.5
6222F–ATARM–14-Jan-11
Receiver Ready
Receiver Overrun
Parity Error
Figure 30-3. Start Bit Detection
Figure 30-4. Character Reception
When a complete character is received, it is transferred to the DBGU_RHR and the RXRDY sta-
tus bit in DBGU_SR (Status Register) is set. The bit RXRDY is automatically cleared when the
receive holding register DBGU_RHR is read.
Figure 30-5. Receiver Ready
If DBGU_RHR has not been read by the software (or the Peripheral Data Controller) since the
last transfer, the RXRDY bit is still set and a new character is received, the OVRE status bit in
DBGU_SR is set. OVRE is cleared when the software writes the control register DBGU_CR with
the bit RSTSTA (Reset Status) at 1.
Figure 30-6. Receiver Overrun
Each time a character is received, the receiver calculates the parity of the received data bits, in
accordance with the field PAR in DBGU_MR. It then compares the result with the received parity
Example: 8-bit, parity enabled 1 stop
Sampling
RXRDY
Sampling Clock
RXRDY
OVRE
DRXD
DRXD
DRXD
Baud Rate
DRXD
Clock
S
S
0.5 bit
period
D0
D0
True Start Detection
D1
D1
period
D2
1 bit
D2
D3
D0
D3
D4
D4
D1
D5
D5
D6
D6
True Start
Detection
D2
D7
D7
P
P
D3
stop
S
S
D4
Read DBGU_RHR
D0
D0
D1
D1
D5
SAM7SE512/256/32
D2
D2
D3
D3
D6
D4
D4
D5
D5
D7
D6
D6
Parity Bit
D7
D7
P
P
stop
Stop Bit
D0
RSTSTA
303