SH7052 Datasheet, PDF (490/919 Pages) Renesas Technology Corp – SuperHTM RISC engine

• Bit 0—Reserved: This bit always reads 0. Operation cannot be guaranteed if 1 is written.
14.2.10 Inversion of SCK Pin Signal
The signal input from the SCK pin and the signal output from the SCK pin can be inverted by
means of a port control register setting. See the section on port function control for details.
14.3 Operation
14.3.1 Overview
For serial communication, the SCI has an asynchronous mode in which characters are
synchronized individually, and a synchronous mode in which communication is synchronized with
clock pulses. Selection of asynchronous or synchronous mode and the transmission format is made
in the serial mode register (SMR) as shown in table 14.8. The SCI clock source is selected by the
C/A bit in the serial mode register (SMR) and the CKE1 and CKE0 bits in the serial control
register (SCR), as shown in table 14.9.
Asynchronous Mode:
• Data length is selectable: seven or eight bits.
• Parity and multiprocessor bits are selectable, as well as the stop bit length (one or two bits).
These selections determine the transmit/receive format and character length.
• In receiving, it is possible to detect framing errors (FER), parity errors (PER), overrun errors
(ORER), and the break state.
• An internal or external clock can be selected as the SCI clock source.
 When an internal clock is selected, the SCI operates using the on-chip baud rate generator
clock, and can output a clock with a frequency matching the bit rate.
 When an external clock is selected, the external clock input must have a frequency 16 times
the bit rate. (The on-chip baud rate generator is not used.)
Synchronous Mode:
• The communication format has a fixed 8-bit data length.
• In receiving, it is possible to detect overrun errors (ORER).
• An internal or external clock can be selected as the SCI clock source.
 When an internal clock is selected, the SCI operates using the on-chip baud rate generator
clock, and outputs a serial clock signal to external devices.
 When an external clock is selected, the SCI operates on the input serial clock. The on-chip
baud rate generator is not used.
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