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CHAPTER 13 UART
13.4.7 Serial Switch Register (SSEL)

The serial switch register (SSEL) switches the P30/UCK/SCK, P31/UO/SO, and P32/UI/SI

pins between UART and 8-bit serial I/O.

Serial Switch Register (SSEL)
Figure 13.4-9 Serial Switch Register (SSEL)
SSEL
0
1
bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
003BHSSEL -------0B
R/W
R/W
Address Initial value
Serial switch bit
Sets UART.
Sets 8-bit serial I/O.
: Readable/Writable
: Unused
: Initial value
Table 13.4-5 Description of the Serial Switch Register (SSEL) Bits
Bit name Description
bit7
to
bit1 Unused bits The values read out from these bits are undefined.
Writing values to these bits does not affect any operations.
bit0 SSEL:
Serial switch bit When this bit is "0", UART is used.
When this bit is "1", 8-bit serial I/O is used.