Operations In Operation Mode 0 - Fujitsu MB95630H Series Hardware Manual

MB95630H Series
22.6.1

Operations in Operation Mode 0

Operation mode 0 operates as clock asynchronous mode (UART).
■ Operations in UART/SIO Operation Mode 0
Clock asynchronous mode (UART) is selected when the MD bit in the UART/SIO serial mode
control register 1 (SMC1n) is set to "0".
● Baud rate
The serial clock is selected by the CKS bit in the SMC1n register. Be sure to select the
dedicated baud rate generator at this time.
The baud rate is equivalent to the output clock frequency of the dedicated baud rate generator,
divided by four. The UART can perform communication within the range from −3% to +3% of
the selected baud rate.
The baud rate generated by the dedicated baud rate generator is obtained from the equation
illustrated below. (For information about the dedicated baud rate generator, see "CHAPTER 23
UART/SIO DEDICATED BAUD RATE GENERATOR".)
Figure 22.6-1 Baud Rate Calculation when Using Dedicated Baud Rate Generator
Baud rate value =
UART prescaler select register (PSSRn)
Prescaler select (PSS[1:0])
Table 22.6-2 Sample Asynchronous Transfer Rates Based on Dedicated Baud Rate Generator
(Machine clock = 10 MHz, 16 MHz, 16.25 MHz)
Dedicated baud rate generator setting
Prescaler select Baud rate counter
PSS[1:0] setting BRS[7:0]
1 (Setting value: 0,0)
1 (Setting value: 0,0)
1 (Setting value: 0,0)
1 (Setting value: 0,0)
1 (Setting value: 0,0)
2 (Setting value: 0,1)
4 (Setting value: 1,0)
8 (Setting value: 1,1)
MN702-00009-1v0-E
Machine clock (MCLK)
1
×
4
2
4
8
Internal
Total division ratio
UART
(PSS × BRS × 4)
division
20 4
22 4
44 4
87 4
130 4
130 4
130 4
130 4
FUJITSU SEMICONDUCTOR LIMITED
22.6 Operations and Setting Procedure Example
2
×
:
255
UART baud rate setting register (BRSRn)
Baud rate setting (BRS[7:0])
Baud rate
(10 MHz /
Total division
ratio)
80 125000
88 113636
176 56818
348 28736
520 19231
1040 9615
2080 4808
4160 2404
CHAPTER 22 UART/SIO
[bps]
Baud rate Baud rate
(16 MHz / (16.25 MHz /
Total division Total division
ratio) ratio)
200000 203125
181818 184659
90909 92330
45977 46695
30769 31250
15385 15625
7692 7813
3846 3906
463