DF36912GFH Renesas Electronics America, DF36912GFH Datasheet - Page 267

• Manufacturer Part Number: DF36912GFH
• Description: MCU 3/5V 8K 32-LQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8/300H Tinyr

Specifications of DF36912GFH

• Core Processor: H8/300H
• Core Size: 16-Bit
• Speed: 12MHz
• Connectivity: I²C, SCI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 18
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

14.8.4
In asynchronous mode, SCI3 operates on a basic clock with a frequency of 16 times the transfer
rate. In reception, SCI3 samples the falling edge of the start bit using the basic clock, and performs
internal synchronization. Receive data is latched internally at the rising edge of the 8th pulse of the
basic clock as shown in figure 14.20. Thus, the reception margin in asynchronous mode is given
by formula (1) below.
Legend N : Ratio of bit rate to clock (N = 16)
Assuming values of F (absolute value of clock rate deviation) = 0 and D (clock duty) = 0.5 in
formula (1), the reception margin can be given by the formula.
However, this is only the computed value, and a margin of 20% to 30% should be allowed for in
system design.
M = (0.5 –
D : Clock duty (D = 0.5 to 1.0)
L : Frame length (L = 9 to 12)
F : Absolute value of clock rate deviation
M = {0.5 – 1/(2
Receive Data Sampling Timing and Reception Margin in Asynchronous Mode
Internal basic
clock
Receive data
(RxD)
Synchronization
sampling timing
Data sampling
timing
Figure 14.20 Receive Data Sampling Timing in Asynchronous Mode
2N
1
) –
16)}
0
D – 0.5
8 clocks
Start bit
N
100 [%] = 46.875%
16 clocks
– (L – 0.5) F
7
Section 14 Serial Communication Interface 3 (SCI3)
100(%)
15 0
Rev. 3.00 Sep. 14, 2006 Page 237 of 408
D0
7
... Formula (1)
REJ09B0105-0300
15 0
D1