DF2345TE20 Renesas Electronics America, DF2345TE20 Datasheet - Page 470

• Manufacturer Part Number: DF2345TE20
• Description: MCU 5V 128K 100-TQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2300r

Specifications of DF2345TE20

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: SCI, SmartCard
• Peripherals: POR, PWM, WDT
• Number Of I /o: 71
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 4K 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: 100-TQFP, 100-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Other names: HD64F2345TE20; HD64F2345TE20

Section 12 Serial Communication Interface (SCI)
Clock
Either an internal clock generated by the on-chip baud rate generator or an external clock input at
the SCK pin can be selected as the SCI’s serial clock, according to the setting of the C/A bit in
SMR and the CKE1 and CKE0 bits in SCR. For details of SCI clock source selection, see table
12.9.
When an external clock is input at the SCK pin, the clock frequency should be 16 times the bit rate
used.
When the SCI is operated on an internal clock, the clock can be output from the SCK pin. The
frequency of the clock output in this case is equal to the bit rate, and the phase is such that the
rising edge of the clock is in the middle of the transmit data, as shown in figure 12.3.
0
D0
D1
D2
D3
D4
D5
D6
D7
0/1
1
1
1 frame
Figure 12.3 Relation between Output Clock and Transfer Data Phase
(Asynchronous Mode)
Data Transfer Operations
SCI initialization (asynchronous mode): Before transmitting and receiving data, you should first
clear the TE and RE bits in SCR to 0, then initialize the SCI as described below.
When the operating mode, transfer format, etc., is changed, the TE and RE bits must be cleared to
0 before making the change using the following procedure. When the TE bit is cleared to 0, the
TDRE flag is set to 1 and TSR is initialized. Note that clearing the RE bit to 0 does not change the
contents of the RDRF, PER, FER, and ORER flags, or the contents of RDR.
When an external clock is used the clock should not be stopped during operation, including
initialization, since operation is uncertain.
Rev. 4.00 Feb 15, 2006 page 444 of 900
REJ09B0291-0400