HD6432621 Hitachi, HD6432621 Datasheet - Page 490

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

13.3
13.3.1
The SCI can carry out serial communication in two modes: asynchronous mode in which
synchronization is achieved character by character, and clocked synchronous mode in which
synchronization is achieved with clock pulses.
Selection of asynchronous or clocked synchronous mode and the transmission format is made
using SMR as shown in table 13-8. The SCI clock is determined by a combination of the C/A bit
in SMR and the CKE1 and CKE0 bits in SCR, as shown in table 13-9.
Asynchronous Mode
Clocked Synchronous Mode
446
Data length: Choice of 7 or 8 bits
Choice of parity addition, multiprocessor bit addition, and addition of 1 or 2 stop bits (the
combination of these parameters determines the transfer format and character length)
Detection of framing, parity, and overrun errors, and breaks, during reception
Choice of internal or external clock as SCI clock source
Transfer format: Fixed 8-bit data
Detection of overrun errors during reception
Choice of internal or external clock as SCI clock source
When internal clock is selected:
When external clock is selected:
When internal clock is selected:
When external clock is selected:
The SCI operates on the baud rate generator clock and a clock with the same frequency as
the bit rate can be output
A clock with a frequency of 16 times the bit rate must be input (the on-chip baud rate
generator is not used)
The SCI operates on the baud rate generator clock and a serial clock is output off-chip
The on-chip baud rate generator is not used, and the SCI operates on the input serial clock
Operation
Overview