CHAPTER 12 SERIAL INTERFACE 20
(b) Generation of baud rate transmit/receive clock from external clock input to ASCK20 pin
The transmit/receive clock is generated by scaling the clock input from the ASCK20 pin. The baud rate
of a clock generated from the clock input to the ASCK20 pin is estimated by using the following
expression.
fASCK
16
[Baud rate] =
[Hz]
fASCK: Frequency of clock input to the ASCK20 pin
Table 12-4. Relationship Between ASCK20 Pin Input Frequency
and Baud Rate (When BRGC20 Is Set to 80H)
Baud Rate (bps)
75
ASCK20 Pin Input Frequency (kHz)
1.2
2.4
150
300
4.8
600
9.6
1,200
2,400
4,800
9,600
19,200
31,250
38,400
19.2
38.4
76.8
153.6
307.2
500.0
614.4
User’s Manual U15075EJ1V0UM00
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NEC [ NEC ]
