DF71251AD50FPV Renesas Electronics America, DF71251AD50FPV Datasheet - Page 466

• Manufacturer Part Number: DF71251AD50FPV
• Description: MCU RISC FLASH 32K 8K 64LQFP
• Manufacturer: Renesas Electronics America
• Series: SuperH® SH Tinyr

Specifications of DF71251AD50FPV

• Core Processor: SH-2
• Core Size: 32-Bit
• Speed: 50MHz
• Connectivity: SCI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 37
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

12.4.2
In asynchronous mode, each transmitted or received character begins with a start bit and ends with
a stop bit. Serial communication is synchronized one character at a time.
The transmitting and receiving sections of the SCI are independent, so full duplex communication
is possible. Both the transmitter and receiver have a double-buffered structure so that data can be
read or written during transmission or reception, enabling continuous data transfer.
Figure 12.2 shows the general format of asynchronous serial communication. In asynchronous
serial communication, the communication line is normally held in the mark (high) state. The SCI
monitors the line and starts serial communication when the line goes to the space (low) state,
indicating a start bit. One serial character consists of a start bit (low), data (LSB first), parity bit
(high or low), and stop bit (high), in that order.
When receiving in asynchronous mode, the SCI synchronizes at the falling edge of the start bit.
The SCI samples each data bit on the eighth pulse of a clock with a frequency 16 times the bit rate.
Receive data is latched at the center of each bit.
Rev. 5.00 Mar. 06, 2009 Page 446 of 770
REJ09B0243-0500
Serial
data
Operation in Asynchronous Mode
Figure 12.2 Example of Data Format in Asynchronous Communication
1
Start
bit
1 bit
0
LSB
D0
(8-Bit Data with Parity and Two Stop Bits)
One unit of transfer data (character or frame)
D1
D2
Transmit/receive data
D3
7 or 8 bits
D4
D5
D6
MSB
D7
Parity
bit
1 bit or
none
0/1
Stop bit
1
1 or 2 bits
1
(mark state)
Idle state
1