420
Bit 3—Stop Bit Length (STOP):
Selects 1 or 2 bits as the stop bit length in asynchronous mode.
The STOP bits setting is only valid in asynchronous mode. If clocked synchronous mode is set the
STOP bit setting is invalid since stop bits are not added.
Bit 3
STOP
Description
0
1 stop bit: In transmission, a single 1 bit (stop bit) is added to the end of each
transmitted character before it is sent
(Initial value)
1
2 stop bits: In transmission, two 1 bits (stop bits) are added to the end of each
transmitted character before it is sent
In reception, only the first stop bit is checked, regardless of the STOP bit setting. If the second
stop bit is 1, it is treated as a stop bit; if it is 0, it is treated as the start bit of the next transmit
character.
Bit 2—Multiprocessor Mode (MP):
Selects multiprocessor format. When multiprocessor format
is selected, the PE bit and O/
E
bit parity settings are invalid. The MP bit setting is only valid in
asynchronous mode; it is invalid in clocked synchronous mode.
For details of the multiprocessor communication function, see section 12.3.3, Multiprocessor
Communication Function.
Bit 2
MP
Description
0
Multiprocessor function disabled
(Initial value)
1
Multiprocessor format selected
Bits 1 and 0—Clock Select 1 and 0 (CKS1, CKS0):
These bits select the clock source for the
baud rate generator. The clock source can be selected from , /4, /16, and /64, according to the
setting of bits CKS1 and CKS0.
For the relation between the clock source, the bit rate register setting, and the baud rate, see
section 12.2.8, Bit Rate Register.
Bit 1
Bit 0
CKS1
CKS0
Description
0
0
clock
(Initial value)
1
/4 clock
1
0
/16 clock
1
/64 clock