Operation Of The U-Timer - Fujitsu FR60 Hardware Manual

6.2.3

Operation of the U-TIMER

This section describes the U-TIMER operation.
■ Calculation of Baud Rate
The UART uses the underflow flip-flop (f.f. in the block diagram shown in Figure 6.2-1 ) of the
corresponding U-TIMER (from U-TIMER0 to UART0, from U-TIMER1 to UART1, from U-TIMER2 to
UART2, from U-TIMER3 to UART3, or from U-TIMER4 to UART4) as the clock source for baud rates.
●
Asynchronous (start-stop synchronization) mode
The UART uses the U-TIMER output divided by 8.
bps =
bps =
Maximum bps peripheral machine clock (CLKP): 25MHz, 1562500bps
●
CLK synchronous mode
bps =
bps =
Maximum bps peripheral machine clock (CLKP): 25MHz, 12500000bps
Note:
Please do not set UTIMR (reload register) to "0" when you use U-TIMER by Mode 2 (CLK
synchronous mode) of UART as baud rate.
(2n+2) 8
UCC 1=1
(2n+3) 8
(2n+2)
UCC 1=1
(2n+3)
: UTIMR (reload value)
n
: Peripheral machine clock frequency
UCC 1=0
(Varies depending on the gear)
n: UTIMR (reload value)
: Peripheral machine clock frequency
UCC 1=0
(Varies depending on the gear)
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