HD64F7051SFJ20V Renesas Electronics America, HD64F7051SFJ20V Datasheet - Page 420

• Manufacturer Part Number: HD64F7051SFJ20V
• Description: MCU 5V 256K J-TEMP PB-FREE QFP-1
• Manufacturer: Renesas Electronics America
• Series: SuperH® SH7050r

Specifications of HD64F7051SFJ20V

• Core Processor: SH-2
• Core Size: 32-Bit
• Speed: 20MHz
• Connectivity: EBI/EMI, SCI
• Peripherals: DMA, WDT
• Number Of I /o: 102
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 10K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 168-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Section 13 Serial Communication Interface (SCI)
When an external clock is input at the SCK pin, it must have a frequency equal to 16 times the
desired bit rate.
When the SCI operates on an internal clock, it can output a clock signal at the SCK pin. The
frequency of this output clock is equal to the bit rate. The phase is aligned as in figure 13.3 so that
the rising edge of the clock occurs at the center of each transmit data bit.
SCI Initialization (Asynchronous Mode): Before transmitting or receiving, clear the TE and RE
bits to 0 in the serial control register (SCR), then initialize the SCI as follows.
When changing the operation mode or communication format, always clear the TE and RE bits to
0 before following the procedure given below. Clearing TE to 0 sets TDRE to 1 and initializes the
transmit shift register (TSR). Clearing RE to 0, however, does not initialize the RDRF, PER, FER,
and ORER flags and receive data register (RDR), which retain their previous contents.
When an external clock is used, the clock should not be stopped during initialization or subsequent
operation. SCI operation becomes unreliable if the clock is stopped.
Figure 13.4 is a sample flowchart for initializing the SCI. The procedure is as follows (the steps
correspond to the numbers in the flowchart):
1. Select the communication format in the serial mode register (SMR).
2. Write the value corresponding to the bit rate in the bit rate register (BRR) unless an external
3. Select the clock source in the serial control register (SCR). Leave RIE, TIE, TEIE, MPIE, TE
4. Wait for at least the interval required to transmit or receive one bit, then set TE or RE in the
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REJ09B0273-0500
Figure 13.3 Output Clock and Communication Data Phase Relationship (Asynchronous
clock is used.
and RE cleared to 0. If clock output is selected in asynchronous mode, clock output starts
immediately after the setting is made to SCR.
serial control register (SCR) to 1. Also set RIE, TIE, TEIE and MPIE as necessary. Setting TE
or RE enables the SCI to use the TxD or RxD pin. The initial states are the marking transmit
state, and the idle receive state (waiting for a start bit).
0
D0
D1
D2
D3
1 frame
D4
D5
Mode)
D6
D7
0/1
1
1