U-Timer Operation - Fujitsu FR60 Hardware Manual

8.3

U-TIMER Operation

This section describes calculation of a baud rate for the U-TIMER and the timing in
cascade mode.
■ Calculation of Baud Rate
The UART uses the underflow flip-flop (f.f. in the block diagram) of the corresponding U-TIMER
(from U-TIMER0 to UART0 or from U-TIMER1 to UART1 or from U-TIMER2 to UART2) as the
clock source for baud rates.
❍ Asynchronous (start-stop synchronization) mode
The UART uses the U-TIMER output divided by 16.
[If UCC1=0]
[If UCC1=1]
❍ CLK synchronous mode
[If UCC1=0]
[If UCC1=1]
Note:
When U-TIMER is used as a baud rate in UART mode 2 (CLK synchronous mode), setting "0" to
UTIMR is prohibited.
φ
bps =
(2n+2) × 16
n : UTIMR (reload value)
φ :
Peripheral machine clock frequency
φ
bps =
(2n+3) × 16
Maximum bps 34 MHz 531250 bps, 68 MHz 1062500 bps
φ
bps =
(2n+2)
n: UTIMR (reload value)
φ: Peripheral machine clock frequency
φ
(Varies depending on the gear)
bps =
(2n+3)
Maximum bps 34 MHz 8500000 bps, 68 MHz 17000000 bps
(Varies depending on the gear)
CHAPTER 8 U-TIMER
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