UART0 to UART2
M30240 Group
Rev.1.00 Sep 24, 2003 Page 80 of 360
UARTi (i = 0 to 2) has two operation modes: a clock synchronous serial I/O mode and a clock
asynchronous serial I/O mode (UART mode). The contents of the serial I/O mode select bits (bits 0 to 2
at addresses 03A0
16
, 03A8
16
and 0378
16
) determine whether UARTi is used as a clock synchronous
serial I/O or as a UART. Although a few functions are different, UART0 and UART1 have almost the
same functions.
UART0 through UART2 are almost equal in their functions with minor exceptions.Table 1.24 shows the
comparison of functions of UART0 through UART2, and Figure 1.76, Figure 1.77, Figure 1.78, Figure
1.79, and Figure 1.80 show the registers related to UARTi.
Note 1: Only during clock synchronous serial I/O mode.
Note 2: Only during clock synchronous serial I/O mode and 8-bit UART mode.
Note 3: Only during UART mode.
Note 4: Used for SIM interface.
Table 1.24: Comparison of functions of UART0 through UART2
Function UART0 UART1 UART2
CLK polarity selection Possible (Note 1) Possible (Note 1) Possible (Note 1)
LSB first / MSB first selection Possible (Note 1) Possible (Note 1) Possible (Note 2)
Continuous receive mode selection Possible (Note 1) Possible (Note 1) Possible (Note 1)
Transfer clock output from multiple pins selection Impossible Possible (Note 1) Impossible
Serial data logic switch Impossible Impossible Possible (Note 4)
Sleep mode selection Possible (Note 3) Possible (Note 3) Impossible
TxD, RxD I/O polarity switch Impossible Impossible Possible
TxD, RxD port output format CMOS output CMOS output CMOS output
Parity error signal output Impossible Impossible Possible (Note 4)
Bus collision detection Impossible Impossible Possible
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