DF2357F20 Renesas Electronics America, DF2357F20 Datasheet - Page 519

• Manufacturer Part Number: DF2357F20
• Description: IC H8S MCU FLASH 5V 128K 128QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2300r

Specifications of DF2357F20

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: SCI, SmartCard
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 87
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 128-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

14.3.2
In asynchronous mode, characters are sent or received, each preceded by a start bit indicating the start of communication
and one or two stop bits indicating the end of communication. Serial communication is thus carried out with
synchronization established on a character-by-character basis.
Inside the SCI, the transmitter and receiver are independent units, enabling full-duplex communication. Both the
transmitter and the receiver also have a double-buffered structure, so that data can be read or written during transmission
or reception, enabling continuous data transfer.
Figure 14-2 shows the general format for asynchronous serial communication.
In asynchronous serial communication, the transmission line is usually held in the mark state (high level). The SCI
monitors the transmission line, and when it goes to the space state (low level), recognizes a start bit and starts serial
communication.
One serial communication character consists of a start bit (low level), followed by data (in LSB-first order), a parity bit
(high or low level), and finally one or two stop bits (high level).
In asynchronous mode, the SCI performs synchronization at the falling edge of the start bit in reception. The SCI samples
the data on the 8th pulse of a clock with a frequency of 16 times the length of one bit, so that the transfer data is latched at
the center of each bit.
Data Transfer Format: Table 14-10 shows the data transfer formats that can be used in asynchronous mode. Any of 12
transfer formats can be selected according to the SMR setting.
Operation in Asynchronous Mode
Serial
data
1
Start
bit
1 bit
0
LSB
Figure 14-2 Data Format in Asynchronous Communication
D0
One unit of transfer data (character or frame)
(Example with 8-Bit Data, Parity, Two Stop Bits)
D1
D2
Transmit/receive data
D3
7 or 8 bits
D4
D5
D6
MSB
D7
Parity
bit
1 bit,
or none
0/1
Rev.6.00 Oct.28.2004 page 489 of 1016
Stop bit
1
1 or
2 bits
1
Idle state
(mark state)
1
REJ09B0138-0600H