Baud Rate Of The External Clock (One-To-One Mode) - Fujitsu F2MC-16LX Hardware Manual

21.6.3

Baud Rate of the External Clock (One-to-one Mode)

Indicates the formula for the settings and the baud rates for selecting the external clock,
as UART transfer clock.
Baud Rate of the External Clock (One-to-one Mode)
Selecting the baud rate of external clock (one-to-one mode) requires the following three settings.
Write "0" in MD bit of UART prescaler control registers 0 to 3 (UTCR0 to UTCR3), and "1" to CKS bit,
and select the baud rate resulting from the external clock (one-to-one mode).
Set SCK pins 0 to 3 to Enter (DDR4: bit4=0, bit7=0, DDR9: bit2=0, bit5=0).
Write "0" in SCKE bit of the serial mode registers 0 to 3 (SMR0 to SMR3) to define the pin as external
clock input pin.
It is used in the synchronous modes.
Calculation expression for baud rate
When the baud rate resulting from the external clock (one-to-one mode) is selected (UTCR0 to UTCR3:
MD=0, CKS=1), resulted baud rate is as follows (f for the frequency of the external clock).
Synchronous = f' (bps)
f': External clock frequency
However, the maximum of f' is up to 1/8 of the machine clocks.
CHAPTER 21 UART
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